Kansas State UniversityAgricultural Experiment Station and

Cooperative Extension Service

AnAnnotated Chronology of

RESEARCHHIGHLIGHTS

at theAgricultural Research Center—Hays

100TH ANNIVERSARY

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AN ANNOTATED CHRONOLOGY OFRESEARCH HIGHLIGHTS

Agricultural Research Center–HaysJohn R. Brethour, Keith R. Harmoney, Tom L. Harvey, Kenneth D. Kofoid, T. Joe Martin,

Dallas L. Seifers, Phillip W. Stahlman, and Carlyle A. Thompson

SUMMARY

This chronology was compiled by the current scientists at the Agricultural Research Center–Hays and

includes highlights of eight areas of research: beef cattle, entomology, plant pathology, range manage-

ment, soil, sorghum, weed management, and wheat. Investigations on these subjects have been conducted

for various periods of time from 50 years to nearly 100 years. Considerable research also was done on

forage crops from 1913 to 1969 mainly by Harold Hackerott and on alternative crops from 1971 to 1998

by William Stegmeier. Information about those areas, more details on research programs discussed here,

and a lengthy list of publications can be found in A History of the Agricultural Research Center–Hays,

The First 100 Years (Bulletin 663 of the Kansas Agricultural Experiment Station).

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Beef Cattle Research, John R. Brethour, Beef Cattle Scientist

Compiling this chronology revealed several common threads through the years.• An emphasis on topics that benefit producers in the region served by the station.• A focus on addressing the problem and getting practical answers to the topic or question at

hand.• A concern for quality research with sound experimental design and execution and appropriate

analysis and synthesis.• Conducting truly novel research; virtually all of the effort at Hays has been original and

independent.

1914. The first Roundup program was held. Testsreported were a comparison of cottonseed cakeand linseed meal for cows and use of rationswith wheat straw for growing out calves.

1931. The first wheat feeding trial was con-ducted. Wheat feeding became a major topicand continued to be so through the 1960s.

1932. The first comparisons were made ofdifferent sorghums: milo versus kafir grains andsorgo versus kafir silages. (Before the advent ofhybrids, sorghums were identified by species,and old feed analysis tables contain separateentries for kafir and milo.)

1933. A trial showed no response to a phospho-rus supplement, indicating that feeds grown inthe Hays area have adequate levels. (Based onthat study, we have never added phosphorus tothe feedlot rations. Retrospectively, we realizethat this has been an immense contribution tothe environment.)

1934. All studies during the year involved Rus-sian thistle, because that was the only plant thatgrew in the drought.

1920. C.W. McCampbell from the Animal Sci-ences Department in Manhattan took charge ofbeef cattle research at Hays. This added disci-pline to the tests. He continued in this capacityfor 25 years until 1945.

1920s. Emphasis was on roughages grown inwestern Kansas, especially fodders and stoversof sorghums: kafir, cane, and sudan. Extensiveresearch on chopping and grinding roughagesshowed no advantage to chopping but a re-sponse to grinding when forages contained seedsuch as kafir fodder. Research also showed thatprotein needs could be met with alfalfa hayinstead of purchased supplements.

The second annual Roundup was held April 1, 1915. In mostyears the program was held in April. As indicated by the fire,

everyone quickly learned to dress for cold weather onRoundup day.

View of research feedlot in 1937. The upright silos were torndown soon after this, and the sheds in the pens were removedin the 1960s.

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1930. The first beef cattle study using a repli-cated design was conducted. Good sciencerequires replication. Most cattle research facili-ties have large numbers of small pens to allowsuch replication. However, the procedure at Haysusually has been to replicate over time withdifferent cattle and environments. That providesa more critical assessment of treatment effects.

1930s. Intensive research showed little differenceamong protein supplements. That was animportant finding, because present knowledgeof rumen function explains why no differencewould have been expected.

1943. The first “systems” study was conducted inwhich the carryover effects of different levels ofwintering were followed through summergrazing and growth in the second winter. Be-cause the cattle project includes all stages of theproduction cycle, this approach can be executedeasily here—unlike many other locations.

1945. A.D. Webber briefly took charge of thebeef cattle research but was replaced by FrankKessler in 1947. The first cattle finishing trialin western Kansas was conducted. Previously,that side of the state had been regarded assuitable only for growing stocker cattle andshipping feeders east. This trial heralded the

cattle feeding industry of western Kansas. Thistrial also involved the first attempt to documentthe feeding value of the combine grain sorghums(e.g., Midland milo).

1949. The first breeding study to determine theeffect of sire on feed efficiency was conducted.Up to this time, the Station had focused onimproving the genetics of the cow herd todemonstrate the importance of careful selectionin building up the quality of commercial herdsin the region. But the cow herd had not beendirectly involved in research.

1950s. More research was conducted at Hays onfeeding wheat to cattle than at any other loca-tion. The major topics included relative value ofwheat to other grains, differences among wheattypes, and management of wheat in finishingrations.

1953. The first trial with feed additives consid-ered the antibiotics bacitracin and aureomycin.Many trials with additives were conducted untilthe 1980’s, but then diminished because privatefacilities had been developed to take on the roleof product testing.

1953. An intensive study of creep feeding started.This was a popular topic at that time but didnot withstand critical research. It was not anefficient or economical practice, and many of thecontentions of its advocates were proven untrue.

1955. The first trial with stilbestrol was con-ducted. This was the first of the growth-promot-ing hormones so pervasively used in cattleproduction. Stilbestrol eventually was removedfrom use because of human health concerns.

1955. A project was initiated to measure theheritability of feedlot gain by comparing theperformance of half-sib bulls with that of theirprogeny. This study validated performancetesting of sire candidates that is used widely tothis day.

One of the early livestock judging contests held in the 1930s.The judging contests traditionally were held the day after

Roundup (Saturday), and 4-H and FFA judging teams fromcounties and schools west of highway 81 were invited. This

event provided most rural youth an introducton to the researchcenter that they remembered all their lives.

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1957. John Brethour took over the beef cattleresearch program and conducted the first ofmany silage studies. The station had fourexperimental silos, and two more were added inthat year. Many of the details of silage manage-ment and also selection of best sorghum culti-vars for silage were established by the studiesconducted at this location.

1958. Studies began to follow cattle to the pack-ing plant and collect individual carcass data.Because treatment effects on carcass quality maybe as important as performance responses, thispractice has been used consistently through theensuing years.

1959. Ultrasound was used for the first time atthis location to evaluate cattle. Dr. Jim Stoufferfrom Cornell University brought his prototypeinstrument to measure cattle that were commit-ted to an extensive cutout study. The samecattle (Hereford steers) were evaluated byCharles Murphy of the USDA, and the datawere used to construct the yield grade equationthat is still in use.

1959. A toxic reaction was observed after sys-temic insecticide treatment for cattle grubs. Thisled to a revision in labeling of those pesticides,warning against use of the product after thegrub has matured because its destructionresulted in production of toxins that got intothe animal’s system.

1959. The first experiment using wheat in afinishing ration was conducted. Results indi-cated the advantage of using 50% wheat and50% rolled milo, which later was identified asbeing due to the associative effect of combiningrapidly and slowly digested grains.

1959. The first of many studies was conductedwith growth-promoting implants (stilbestrol).

1961. A high-concentrate finishing ration wasstudied for the first time. Until then, rationsthat were more concentrated than one part

silage to one part grain were suspect. Resultsshowed substantial advantages for the high-grainrations, and this response later was explained bythe negative associative effect that depressesroughage digestibility when grain exceeds about20% of the ration.

1961. Studies began on the use of ensiled high-moisture grain in feed.

1962. Studies showed that a simple finishingration of rolled milo, sorghum silage, and alfalfahay resulted in very satisfactory performance.

1963. All-concentrate finishing rations wereinvestigated. These worked very well in smallexperimental groups but proved disastrouswhen attempted in a commercial feedlot envi-ronment with large numbers of cattle per pen.This emphasized the importance of consideringevaluations of new ideas in field situations.

1963. We had our first access to a mainframecomputer (an IBM 1401 on the Fort Hays StateUniversity campus). We developed a generallinear model (GLM) statistical program thatpreceded the one now provided by the SASInstitute by 13 years. The program allowedimproved statistical precision in the cattleresearch and enhanced the scientific quality ofthe experiments. That computer had only 16Kmemory but could invert a 50 X 50 matrix ifintermediate calculations were exported ontopunch cards and reloaded for the next phase.That task took about 50 minutes.

1965. Research showed an advantage to feedingwaxy endosperm sorghum grain. This was animportant indication that endosperm mightaffect feeding value of different types of sor-ghum.

1966. Don Ely took over the research programfor two years; John Brethour resumed in 1968.Investigations started on the use of high levelsof urea to replace natural protein in cattlerations. Use of ammonium chloride to suppress

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urinary calculi and provide non-protein nitrogenalso was investigated.

1970. The first study was done with ultrasoundon live cattle to predict future carcass merit.

1971. Intensive evaluation of different wheattypes showed that hard red winter wheat wasequal or superior in cattle rations and thwartedinterest in developing a specific feed wheat.

1971. One of the “Holy Grails” in cattle produc-tion would be a method to induce marbling andartificially increase carcass grade. Preliminaryinvestigations suggested that dexamethasonemight effect such a response.

1972. We published the first report (from anylocation) that implants depress carcass grade.This observation was largely ignored untilproducers started selling on a grade and yieldbasis.

1972. Additions of thiamin and sodium bicarbon-ate enabled use of 100% wheat in a finishingration. Those additives appeared to circumventthe acidosis commonly encountered with high

wheat levels. (Later studies showed that iono-phores were equally effective in addressing thisproblem). Several trials were conducted withadded thiamin in stress situations and provokedmuch interest.

1973. We reported the first observation of aresponse to reimplanting cattle during thefinishing phase. It took another 10 years beforethis became a common feedlot practice.

1974. A preliminary trial was conducted compar-ing different breeds crossed on Hereford cows,including Simmental, Limousin, Charolais, andHolstein. The Continental breeds from Europehad just arrived in this country. This effort wasnot continued because the USDA Meat AnimalResearch Center opened in Nebraska with moreappropriate resources to conduct breed evalua-tions. But, in later years, the Hays projectevaluated breeds not included in the MARCprotocols, including Longhorn, White Park,Braford, and Wagyu.

1975. Intensive work began on feeding out youngbulls. One item driving this research was thepossibility that growth-promoting implantsmight be banned, so exploiting the naturalhormones in intact males would have merit.

View of part of the station cowherd and the arena at the 1974Roundup. The arena gradually evolved from portable open

bleachers into a comfortable roofed area. Only Hereford cattlewere maintained at the Hays Center until the time of this

picture. Then out-crossing with other breeds began.

Another view of the 1974 crowd at Roundup. In those years,before most producers also were encumbered by off-farm jobs,several hundred producers attended field days.

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1976. A study showed that an implanting proto-col over the lifetime of an animal could increasetotal gain by more than 100 pounds per animal.

1976. Research showed the advantage of finelyrolled milo over coarsely rolled milo. Citing thiswork and arguing that earlier values had beenobtained with improper processing, i.e., coarserolling, convinced the National Research Coun-cil to substantially increase the energy value ofmilo in feed analysis tables.

1977. We discovered that a novel combination ofa methane inhibitor and an ionophore had asynergistic effect in improving performance andfeed efficiency. Repeated trials with two differ-ent methane inhibitors confirmed this response,but we were unable to persuade the companiesto get the methane inhibitors cleared for use.

1977. We built an interactive program for aminicomputer that calculated balanced rationsfor cattle and then proceeded to select the least-cost formulation. This was farmed out for useby several feed companies and probably was thefirst of its kind.

1979. We attempted to develop a ration to studythe effect of ionophores plus a methane inhibi-tor to combat nitrate toxicity. The strange resultwas that rations with 5,000 to 20,000 ppmnitrate performed better, apparently becauserumen microorganisms were using nitrate as anonprotein nitrogen source.

1982. A summary of eight trials indicated thatfinely rolled milo had 94% the energy value ofrolled corn.

1982. We reported what may be the only trialsever conducted on feeding pearl millet to cattle.

1983. The first trials in the Western Hemispherewith Revalor and the first in the United Stateswith Finaplix (growth implants containingtrenbolone) were conducted. These are amongthe most widely used implants today.

1984. At this time, considerable interest existedin treating wheat straw with ammonia toincrease digestibility and crude protein. Sor-ghum hay was treated with ammonia, andconcrete evidence of toxicity was obtained.Putatively, ammonia reacted with plant sugars toform an imidazole compound that was absorbedby the cow and passed directly to the milk,which was especially lethal to calves. Theseresults were circulated widely and resulted inrecommendations against ammoniating rough-ages that might still contain sugar (e.g., sor-ghums, grass, and immature cereals).

1984. The first cattle trials in the country withzinc methionine (Zinpro) were conducted. Thiscaused nutritionists to suspect that organicsources of minerals might be more available thaninorganic sources.

1985. Developed the one calf heifer system, inwhich a female is bred and allowed to have onecalf, which is weaned early, while the 2-year-oldcow is fed for harvest. This may be the mostefficient of all beef cattle programs but is laborand management intensive. This research wasconducted during one of the “farm crises” andwas promoted as a program to enable maximumprofitability for operations with limited re-sources.

1987. Research began on applying ultrasoundtechnology to beef cattle production. The firsteffort was to exploit serial insonation anddevelop a model for the increase in backfatthickness during the finishing phase.

1988. We discovered that an artifact calledultrasonic speckle is an indicator of marbling(intramuscular fat).

1989. Research showed that cattle managementin a growing-grazing system needs to be attunedto cattle type.

1989. The first studies were conducted thatindicated improved feedlot profit from sorting

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cattle into outcome groups appropriate to thecarcass and performance potential of eachanimal.

1990. Research showed that light test weight milo(48 lb/bu) had 96% the feed value of normalmilo. We seem to receive more producer inquir-ies about the feed value of discounted grainsthan any other topic.

1991. Several experiments during this periodwith the breeding herd addressed improvedmethods of synchronization and timed breeding(artificial insemination).

1992. We perfected computer measurement ofultrasound images to estimate backfat thicknessand marbling score. That involved patternrecognition techniques and neural networktechnology. Three comparisons sponsored by theBeef Improvement Federation showed that theKSU system for estimating marbling was moreaccurate than other systems.

1993. A project studied refeeding cull cows. Theyrepresent an important component in the cashflow of a cow/calf operation. This effortshowed that income could be enhanced ifmarketing systems could be devised to rewardproducers for their extra effort.

1994. We developed a profitability model thatrepresented an expert system to synthesizeultrasound estimates with other parameters topredict days-on-feed for maximum feedlotprofitability.

1995. We established the model for the rate ofmarbling increase in feedlot steers.

1997. Research showed adverse effect of supple-menting low quality roughages with high starchfeed ingredients (rolled milo).

1998. The first research was completed showingsuccess in estimating potential carcass qualitygrade from ultrasound estimates made on calvesat weaning.

1999. Six steer carcasses managed and selectedwith ultrasound technology placed first in theDenver Stock show carcass contest. All sixgraded USDA Prime and were acclaimed to bethe best carcasses ever observed. They werefrom a set of Wagyu X Charolais steers thatwere fed to validate models of marbling in-crease. U.S. Patent 5,960,105 was granted for anultrasound procedure to measure intramuscularfat in cattle.

John Brethour with a pair of ultrasound instruments. ARCHbecame a leader in the development of ultrasound applicationsfor beef cattle in the last decade of the century.

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Entomology Research, Tom L. Harvey, Entomologist

Woodrow Franklin was hired in 1948 as the first full-time entomologist and studied alfalfainsects. He was replaced in 1954 by Tom Harvey.

The studies mentioned here involved the cooperative efforts of many scientists, and results havebeen published in refereed journals.

BEEF CATTLE

1960s. Research showed that feeding cattleBacillus thuringensis spore powder preventeddevelopment of house fly larvae in the manure.We also discovered that short-nosed cattle louseinfestations were more severe on cattle thatwere fed urea compared with cottonseed meal.

1970s. We originated the idea for insecticide eartags to control horn flies and face flies andpublished the first results. The adverse effect ofhorn flies on weight gains of yearling steers wasrecorded, and we identified their effect on cattlebehavior that accounted for reduced productiv-ity. We also discovered that whole-herd controlof horn flies could be obtained by partial-herdtreatment with insecticides.

by insecticide in marking fluid applied to cowsby bulls equipped with chin-balls or bull point-markers. They also could be controlled withpellets containing insecticide fired from aCO2-operated pellet pistol. Brahman x Herefordheifers had 70% fewer horn flies than Angus xHereford heifers, so using insecticide ear tags on50% Brahman-cross yearlings provided noeconomic advantage. Livestock insect researchwas discontinued in 1989.

ALFALFA

1950s. We published the first detailed study ofinsects affecting alfalfa seed production inKansas. Cody alfalfa, the first Kansas varietyresistant to spotted alfalfa aphids, was devel-oped and released.

1960s. Kanza alfalfa, the first variety with resis-tance to both the spotted alfalfa aphid and thepea aphid, was developed and released. A fieldrating system was designed to evaluate alfalfa forresistance to pea aphids based on the presenceof parasitized aphids. Research proved that plant

First insecticide ear tag used to control flies on cattle.

1980s. Horn flies were effectively controlled withbackrubbers made from insecticide ear tagsattached to tire chains or sand-filled dust bags.We found that insecticide ear tags applied tonursing calves controlled horn flies on the bothcows and calves. Horn flies also were controlled

Insecticide ear tags on chain backrubber used tocontrol flies.

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products responsible for resistance to spottedalfalfa aphid did not pass through graft unionsof reciprocally grafted resistant and susceptiblealfalfa clones.

MISCELLANEOUS

1960s. Research provided the first example of aninsect becoming resistant to a microbial insecti-cide containing Bacillus thuringensis, which isnow used widely in transgenic corn. We madethe first detailed study of aphids, dodder, anddodder-host plant interrelations using 30 speciesof aphids and 16 host plants.

WHEAT

1980s. Resistance to the wheat curl mite wasfound in wheat-rye addition lines, and agermplasm source of resistance was released.The incidence of wheat streak mosaic in thefield was reduced by 74% in a wheat curl miteresistant line (KS80H4200). Control of wheatcurl mites and a reduction of wheat streakmosaic infection were achieved by a planting-time application of carbofuran. We discoveredthat pubescent wheat provided a more favorablelanding site for airborne wheat curl mites thanglabrous wheat, was more heavily infested withmites, and thus had a higher incidence of wheatstreak mosaic. A 10-year study of greenbug

Wheat curl mite adults and eggs on wheat leaf.

Greenbugs, a major pest of both wheat and sorghum.

flight patterns indicated that both early plantedwheat and sorghum are more likely to be in-fested. We released a germplasm source ofresistance to greenbug derived from Triticumtauschii (goatgrass). Wheat strawworms werefound infesting over 53% of culms in six fields

1970s. Studies found that insecticides applied atrecommended rates for 5 years on a 20-acre fielddid not contaminate groundwater. We studiedleafhopper populations on upland seededpastures at Hays and identified 57 species in 34genera.

1980s. A technique was developed to uniformlyinfest plants with aphids using a mechanicalinsect dispenser. Also, a method was devised toestimate wheat curl mite populations in wheatspikes using sticky tape.

1990s. We determined the effect of sunflowerplanting date on infestation and damage by thesunflower moth. Research on the effects ofdifferential grasshoppers on 15 corn hybridsshowed leaf loss ranged from 8 to 47%, indicat-ing that some hybrids have genetic resistance.

Green peach aphids infesting dodder, a parasitic plant.

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in Ellis County, resulting in a 5-10% yield lossper culm. Laboratory tests showed that theRussian wheat aphid was more cold tolerantthan the greenbug and verified that it survivedthe 1986-87 winter at Hays under conditionsthat were fatal to the greenbug.

1990s. Common wheats resistant to Russianwheat aphids were identified by screening over5000 plant introductions. Resistant germplasmswere released in 1995, and the first Russianwheat aphid-resistant variety from Kansas(Stanton) was released in 1999. New sources ofresistance to greenbugs derived from Triticumtauschii also were released. We identified thefirst sources of resistance to wheat curl mites incommon wheat and released wheat curl mite-resistant germplasm. Studies showed that wheatcurl mites in western Kansas had becomevirulent to the resistant variety TAM 107, andthat wheat curl mites from different statesvaried greatly in their response to TAM 107and other resistant wheats. Results from bothfield and greenhouse tests proved that wheatcurl mites cause yield losses to wheat in additionto that caused by the viruses they transmit.

SORGHUM

From1968, when we first recognized the green-bug as a pest of sorghum, through 2001 weconcentrated on plant resistance. We identifiedthree of the four greenbug biotypes that havebeen or are pests of sorghum (biotypes C in1969, I in 1990, and K in 1995) and releasedthe first source of resistance (KS30) that wasused to produce the first greenbug resistanthybrid in 1975. More information on ourcontinuing efforts to develop sorghums withresistance to greenbugs is reported in the“SORGHUM RESEARCH” section of thispublication.

1980s. Greenbug flight patterns indicated thatseedling sorghum is most vulnerable to infesta-tion during the last week of May and the firstweek of June. We found that greenbug numberswere lower on plants grown in thick stands thanin thin stands, indicating that greenbugs wouldnot exceed economic injury levels on resistanthybrids grown in thick stands. Increased levelsof maize dwarf mosaic virus were found incarbofuran-treated sorghum in the field. Theinsecticide appears to induce increased move-ment of aphids from plant to plant, causingmore plants to become infected.

1990s. Studies in both the field and greenhouseproved that wheat streak mosaic virus can betransmitted to sorghum by the wheat curl mite.Some exotic sorghums are susceptible to Russianwheat aphids, but commercial hybrids appear tobe resistant, so sorghum probably will not serveas an important oversummering host.Imidacloprid seed treatment reduced the spreadof sugar cane mosaic virus when aphid infesta-tions were light but not when populations werehigh. A greenbug-resistant hybrid (DK-39Y) wasfound to be highly resistant to natural infection.

Russian wheat aphids, a relatively new pest in Kansas.

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Plant Pathology Research, Dallas L. Seifers, Plant Pathologist

The plant pathology research program was established in 1974. T. Joe Martin served as the firstpathologist until 1979, when he transferred to the wheat breeding program. Kurt Bender heldthe position for one year, and then Dallas Seifers took over in 1982.

1974. Johnsongrass mosaic virus (JGMV) wasisolated from sorghum.

1975. A large-scale field inoculation procedurewas established to screen for resistance to wheatstreak mosaic virus.

1976. A large-scale field inoculation procedurewas established to screen for resistance to maizedwarf mosaic virus (MDMV) and sugarcanemosaic virus strain B (SCMV-MDB).

1976. Sources of resistance to wheat streakmosaic virus and Aceri tulipae were identified.

1978. Procedures were established for evaluatingresistance to wheat streak mosaic virus.

1982. A technique was found to determine thereaction of sorghum to maize dwarf mosaicvirus using seedlings in a greenhouse.

1983. A large-scale program was established toscreen for JGMV in addition to MDMV andSCMV-MDB.

1984. Optimum conditions were developed forconducting studies of MDMV and SCMV-MDB.

1985. Phenotype responses of sorghum hybridsto infection by MDMV were determined in thefield.

1987. Phenotpye responses of sorghum hybrids toinfection by SCMV-MDB were determined inthe field.

1987. Virus titers were correlated to yield loss insorghums differing in resistance.

1988. An immunological technique was devel-oped to correlate virus titer with tolerance insorghum infected by SCMV-MDB.

1988. An immunological technique was devel-oped to correlate virus titer with tolerance inwheat infected by wheat streak mosaic virus.

1989. Studies identified a phenomenon of in-creased virus infection by aphids treated withinsecticide.

1992. Natural infection of wheat by Agropyronmosaic virus was identified.

1993. Eastern gamagrass was identified as aperennial overwintering host for SCMV-MDBin Kansas.

1993. The reaction of sorghum hybrids to infec-tion by SCMV-MDB in the field was deter-mined.

1995. The reaction of sorghum hybrids to infec-tion by MDMV in the field was determined.

Dr. Dallas L. Seifers, Research Plant Pathologist, works in labwith immobilized pH gradients in an isoelectric focusing

apparatus used to separate proteins.

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1995. Natural infection of wheat by Americanwheat striate mosaic virus was found in Kansas.

1995. Temperature sensitivity was identified inwheat with high levels of resistance to wheatstreak mosaic virus.

1996. Natural infections of sorghum and pearlmillet (crops previously immune) by wheatstreak mosaic virus were identified.

1996. The High Plains virus of wheat was identi-fied in Kansas.

1996. High levels of resistance in sorghum toMDMV, SCMV-MDB, and JGMV were identi-fied.

1997. The wheat curl mite was identified as thevector of the High Plains virus.

1997. A new sorghum-infecting virus coded asB-ID was identified.

1997. A virus-like pathogen was isolated fromwheat with yellow head disease.

1998. The host range of the High Plains viruswas determined.

1998. A new sorghum-infecting virus coded as“Ni” was identified.

1998. Several new sources of temperature-sensi-tive resistance in wheat to wheat streak mosaicvirus were identified.

1999. Natural infection of sorghum by foxtailmosaic virus was found in Kansas.

1999. Additional sources of resistance to wheatstreak mosaic virus were identified in wheat.

2000. Zea mosaic virus, a new-sorghum infectingvirus, was identified and characterized.

2000. A broad-scale program was established toscreen sorghum for resistance to the MDMV,SCMV-MDB, JGMV, sorghum mosaic virus,ZeMV, and Ni and B-ID viruses.

1982-2000. The plant pathology project hasestablished a world-class collection of wheat andsorghum virus isolates and appropriatepolyclonal antisera for use in resistance screen-ing work and research. The program has identi-fied many new viruses and currently is charac-terizing others recently isolated from wheat andsorghum. The program has adapted new tech-nologies and identified high-level resistance inwheat to wheat streak mosaic virus and high-level resistance in sorghum to several viruses.Many national and international collaborativeprojects have been initiated dealing with allphases of the program.

Jeff Ackerman, research assistant, plant pathology project.Putting cages over wheat plants to prevent infestation by wheat

curl mites and other unwanted insects.

Dr. Raffi Salomon,Virologist, ARO,Bet Dagan, Israel.Dr. Salomonworked withwheat andsorghum viruseswhile on sabbaticalleave at KSU-ARCH.

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Range Management Research,

Keith Harmoney, Range and Forage Scientist

Research on native rangelands and associated grasslands began with the intent of increasingproduction while at the same time maintaining the integrity of the land and conserving thenatural resources of vegetation, water, soils, microbes, and animals involved.

1946. Not long after the Great Depression andthe blowing Dust Bowl, Kansas State Universityestablished a range scientist position at theBranch Experiment Station in Hays. FrankKessler was hired to fill that position and also toconduct research on animal feeding. The earlyemphasis of this position was to develop recom-mended stocking rates for native rangelands onthe mixed and short-grass prairies. Years ofdrought and heavy use of cattle on grazing landshad deteriorated native pastures. The conditionof native range following these events promptedthe need for research on their effects in westernKansas.

1949. Pastures of native warm-seasonbuffalograss, native cool-season western wheat-grass, and introduced cool-season intermediatewheatgrass were established. Annual grazingcomparisons of these pastures followed forseveral years. The cool-season wheatgrassesproduced more forage than the low-growingbuffalograss.

1951. Kessler summarized his findings concerningdifferent rates and densities of stocking andtheir effects on rangeland plant populations. Hediscovered that continuous season-long stockingat light and medium rates was not detrimentalto short-grass rangeland vegetation. However,greater animal production was achieved on thesame acreage with medium stocking rates. Evengreater animal production was achieved with thehigh stocking rates, but after 5 years, pasturesshowed signs of overgrazing and loss of desiredplant species. Forage quality in terms of proteinalso was compared between pastures during thisearly study.

1955. John Launchbaugh was hired to lead therange management program and remained for30 years. He continued to focus on stockingdensity and stocking rate research on short-grassrangelands.

Native grasses, such as western wheatgrass and buffalograss, andgrass species introduced from Europe and Asia, were seeded to

compare which would have greater growth and yields forgrazing animal production.

1957. Studies contin-ued on both animalperformance andplant responses to thedifferent densities ofstocking during aseason. Animalproduction wasreduced greatly on aper head basis withheavy stockingbecause of the loss ofdesirable grasses and

Root excavations from light, moderate, and heavy stocking ratestudies on native rangelands showed that heavy grazing eventu-ally decreased native shortgrass root depth and dry-matterproduction.

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forbs. Profile excavations of grasses from eachstocking intensity showed that above- andbelow-ground plant growth was greatest withlight stocking and somewhat less with moderatestocking. Compacted soils in the heavily stockedpastures also reduced soil moisture. Moderate tolight stocking was recommended for cattleproduction on shortgrass prairie.

1963. Launchbaugh started to study other areasof interest in the late 1950s and early 1960s. Hebegan investigations on methods to reseedcropland back into native or introduced forages.A study with Kling Anderson in Manhattanconcluded that spring and early summerplantings of warm-season grasses were mostreliable and that late winter to early summerplantings of native cool-season grasses also weresuccessful. They concluded that amount andtype of residue for ground cover during seedingwas less important than seeding date. Further,to conserve soil and prevent erosion,Launchbaugh studied seeding western wheat-grass with perennial ryegrass or smooth brome-grass into drainages that carried water runoff.

1966. Launchbaugh contributed Kansas results toa report of the Great Plains Council, a group ofstate and federal institutions that studiedestablishment of native grasses through differentmethods on rangelands. Building on his earlierseeding studies, his new findings showed thatgrass establishment was first dependent onprecipitation or soil moisture. If adequatemoisture was present, grass could be establishedduring most periods of the year and by mosttillage and seeding methods.

1967. Research on stocking density continuedinto the 1960s. Vegetation changes were studiedfrom several consecutive years of light, moder-ate, and heavy stocking. Western wheatgrass, ahighly desirable cool-season native grass, basi-cally was eliminated from pastures by heavygrazing. Lightly stocked pastures maintained thegreatest western wheatgrass population. Blue

grama decreased more during drought inheavily stocked pastures than in moderate orlightly stocked pastures. Buffalograss becamethe dominant grass in heavily stocked pastures.This work in Hays on native rangeland pastureswas the foundation for moderate stocking ratesstill recommended for mixed- and short-grassprairies. These same pastures are still in use forgrazing research today.

1969. Knowledge of natural phenomena also mayprovide solutions to future problems. Abnormalheading of blue grama, a warm-season nativegrass, was observed in April, two months priorto the normal date. Launchbaugh found that thiswas due to seedheads initiated in the fall thatresumed growth during unseasonably favorableweather in the early spring. Recurrence ofwintry conditions caused the deformedseedhead structures. Research showed that bluegrama produces seedheads in the followingseason from fall-initiated tillers that overwinter,and that viable seeds are produced by thesetillers if conditions are favorable. This allowscross pollination of naturally occurring variableblue grama plant types within a pasture popula-tion.

1970. A study in collaboration with ClentonOwensby from the Department of Agronomyshowed the best seeding rates to establish six

Many experiments were conducted that analyzed the mostproductive times and methods to seed cropland back intonative grasses, such as this experimental grass planting intostalk stubble.

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different native grasses on soils of the short-grass prairie. Increasing seeding rates increasedthe number of plants established in the firstyear but decreased the percentage of seed thateventually formed established plants. They alsofound that grass species established indepen-dently of each other and could be seededaccording to individual rates of pure live seedrequired to attain the desired composition ofgrass mixtures.

1971. Pure stands of seeded forages also werestudied for animal production. Fertilization ofswitchgrass and Caucasion bluestem monocul-tures produced greater dry matter, gains peranimal, and beef per acre compared to nativewarm-season grass or western wheatgrasspastures. Overall, switchgrass provided thegreatest and most reliable animal productionfrom seeded pastures.

1973. Launchbaugh contributed to a collaborativestudy after blue grama in a fence row in Ne-braska was discovered to have stolons, vegetativestems that spread laterally across the ground andform roots to establish new plants. Blue gramapreviously was not known to have this capabil-ity. Results at Hays showed that blue gramafrom local populations and North Dakotapopulations, as well as the blue grama fromNebraska, were capable of producing stolonsunder manipulation of short day lengths andlow light intensities in the greenhouse. Bluegrama that could produce stolons under naturalconditions could enhance vegetative spread ofnew seedings and establish ground cover morequickly.

1974. A study began in which Launchbaughapplied nitrogen fertilizer to native rangelands.Fertilization increased the carrying capacity ofpastures, so stocking rates could increase by50%. Greater forage production mostly camefrom increases in invading Japanese brome andnative western wheatgrass. Individual animalweight gains were the same in fertilized and

nonfertilized pastures. The variable economicsof fertilizing native rangelands were based onfluctuations in precipitation, nitrogen fertilizerprices, and animal market prices.

1976. Native grass plantings usually require atleast two growing seasons to reach productivitylevels capable of sustainable animal production.Animals traditionally were not placed on newlyseeded stands for fear of seedling mortality.Grazing newly seeded grass stands to reduceweed pressure was found to have no effect onsurvival of new grass seedlings. Research resultsindicated that spring grass plantings could begrazed until August to utilize weed forage toreduce competition for moisture and nutrientsand to allow adequate seedling growth forwinter survival.

1977. Three years of milo grain supplementationfor steers grazing short-grass prairie resulted inno significant individual gains during the lasthalf of the summer grazing season. Animalsgained only one pound per 10 pounds of fedsupplemental grain, a poor feed conversionratio. Launchbaugh and Owensby concluded astudy on prescribed spring burning of short-grass prairie. Forage production was equal forburned and unburned areas during the firstseason. Vegetative composition showed thatwestern wheatgrass production increased andJapanese brome and threeawn productiondecreased on burned areas. Production ofwarm-season short-grasses was reduced greatlyfrom annual burning. They concluded thatspring burning could help to improve grazingdistribution and reduce mulch and dead litterin the first season, but repeated burning maynot be beneficial. Burning periodically couldincrease production and remove weedy species.

1982. Patches of native rangelands had beenobserved previously to be bare of new springgrowth, and spotted cutworms were the possiblecause. Rangelands are capable of recoveringfrom normal infestations, so insects typically are

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noticed only when abnormally high populationsreduce production in localized areas. Studyresults showed that range vegetation requiredtwo growing seasons to attain normal produc-tion following the heavy insect damage. Comple-mentary forages, those used to fill nutritionaland production gaps left by native rangelandsduring dormant or low quality periods, alsowere investigated by Launchbaugh to improveyear-round grazing potential. His results showedthat individual animal gains from grazing small-cereal grain forage during the fall and earlyspring, along with summer annual forages in latesummer, were nearly equal to gains from grazingnative rangelands only. The use of complemen-tary forages allowed for higher stocking rates, anincrease in herd size, and greater returns tomanagement and labor on a per acre basis.

1983. Launchbaugh and three collaboratorssummarized intensive-early stocking trials inHays and Manhattan. Intensive-early stockingentails increasing the number of animals onpasture during the first half of the growingseason and then removing all animals during thelast half of the season. At Hays, double stocking,triple stocking, and triple stocking plus grainsupplement early in the season were compared.Animals double-stocked during the first half ofthe season at Hays had similar gains as animalsstocked continuously. Because more animalswere present, total beef production per acre wasincreased. Animals triple-stocked had lowergains during the first half of the season. How-ever, animals triple-stocked with daily grainsupplement gained nearly as well as the animalsstocked season-long. Triple stocking, even withgrain supplement, was considered too great arisk with highly variable market prices.

1986. Kenneth Olson, the newly appointed rangescientist following Launchbaugh’s retirement,continued the research on intensive-early stock-ing programs for western Kansas.

1989. In a summary of eight years of study onintensive-early stocking, Olson reported thattotal beef production per acre was similarbetween continuous and early double stocking,and vegetative composition of pastures re-mained similar over the course of the study. Heconcluded that early triple stocking producedmore beef per acre than the other two stockingmethods for only the first few years. Triplestocking caused rapid declines in beef produc-tion and desired vegetative composition overtime and was not a sustainable practice.

1991. Supplemental feeding for reproductiveanimals received greater research interest.Gradual energy supplementation increases andsteady energy supplementation were comparedfor effects on reproductive performance ofreplacement heifers. Both supplementationstrategies prior to breeding were adequate toachieve acceptable heifer reproductive perfor-mance.

1992. Mature cows were given a high grain rationfollowing calving to study subsequent cowcondition prior to breeding and conceptionrates. Cows receiving high grain rations (fourpounds per day) in addition to hay had greaterbody condition and weights than cows receivinga hay-only diet. However, conception rates andcalving interval to the next calf crop were notdifferent between the two groups.

1993. Eric Vanzant, who replaced Olson as thestation range scientist, continued his work onmodifying intensive-early grazing systems. Themodified systems entailed double stocking earlyin the season and then removing only half ofthe animals during the latter half of the season.Vanzant found no improvement in beef produc-tion with this modified system. Double stockingearly actually caused a reduction in weight gainsof animals that stayed on pasture season-long.

1995. Earlier studies had shown that Old Worldbluestem could be as productive as nativevegetation in western Kansas, so two varieties,

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WW-Spar and WW-Ironmaster, were comparedfor adaptation and production potential. Nodifference was found between them in terms ofbeef produced per acre or individual animalgains. Both varieties were initially low in crudeprotein, which declined greatly as the growingseason progressed.

1996. Antibiotic feed additives had been usedpreviously to increase gains of feedlot animals,but little prior research had considered animalsfed those same additives while grazing short-grass rangelands. A study found a slight increasein daily performance for animals receiving theadditives compared to animals not receivingthem.

1997. Several studies were underway in whichdifferent supplementation types and amountswere used to investigate effects on digestibility

and energy of low quality, forage sorghum hays.Increasing grain supplements did not improvefiber digestion and substituting other supple-ments for grain increased fiber digestion but didnot result in greater energy consumption.Vanzant concluded that the best way to increaseenergy consumption for cows with greaterenergy requirements was to feed higher qualityforages.

1998. Daily supplementation of steers on nativerangeland with three pounds of a sorghumgrain/soybean meal mixture produced greatergains compared to steers supplemented dailywith three pounds of sorghum grain or one anda half pounds of soybean meal. Protein supple-mentation during the last half of the growingseason proved to be beneficial because of thelow quality forage available during that timeperiod.

1999. Keith Harmoney replaced Vanzant as thestation range scientist. Refinement of stockingrates on modified intensive-early stockingsystems continued.

2000. Investigations began on the evaluation ofdifferent annual and perennial cool-seasongrasses as complementary forages. A studyevaluating the control and utilization of Japanesebrome by early grazing and prescribed springburning was initiated. Another grazing studywas initiated that eventually will evaluate theeconomics and effects on animal performance ofusing annual winter wheat or annual winterwheat with sudangrass as complementaryforages for cow/calf production on nativerangelands.

Some of the more recent grazing studies that investigated beefanimal supplementation, intake, and selection included timingdevices that detected when animals lowered their heads tograze. Records were kept of the amount of time and what

periods of the day animals spent grazing.

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Soil Research, Carlyle A. Thompson, Soil Scientist

This list of highlights in soil research includes many long-term studies. The first soil scientist,L.E. Hazen, stayed less than 2 years and was replaced in 1909 by A.L. Halstead, who remaineduntil 1945. Andrew Erhart held the job from 1946 to 1948, followed by Paul Brown from1949 to 1956 and Ralph Luebs from 1956 to 1959. Carlyle Thompson was hired in 1964.

1907-1954. Fall tillage increased milo yields overspring tillage.

1908-1958. Ongoing studies determined thatwheat and grain sorghum were the major cropsadapted to this geographical area.

tillage with a moldboard plow or lister. However,subsurface tillage equipment left more cropresidue on the soil surface that provided protec-tion against soil and wind erosion.

1909-1934. Data from 26 years showed a closerelation between the quantity of water in thesoil or the depth to which the soil was wet atseeding time and wheat yield. The water quan-tity and depth of wet soil at seeding time werealso useful in predicting failures and in deter-mining the relative importance of the crop’sdependence of precipitation during the growingseason.

Fall plowing with a 3-bottom plow with comfortseat and umbrella.

Preparing land during the fallow period bydiscing with mulepower.

1908-1958. Fallow in the cropping rotationincreased soil storage of precipitation, resultingin significant increases in wheat yields.

1908-1958. Shallow cultivation with a one-waydisk plow or subsurface tillage equipment was assatisfactory for wheat production as deeper

Determining the quantity of soil water using a core sampler thatwas pounded into the soil, then jacked out; a very timeconsuming process.

1912-1957. Yields of grain sorghum after fallowwere nearly twice those of continuous grainsorghum.

1914-1957. Feedlot manure failed to significantlyincrease wheat yields on the Harney silt loamsoil at Hays.

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1916-1946. Nitrogen (N) losses from cultivatedsoils were most rapid immediately after breakingthe native sod. Losses gradually decreased withcontinued cultivation. Row crop productioncaused the largest losses of N, whereas smallgrain production caused the smallest losses.Under small grains, N losses had ceased by1938. Elsewhere, losses continued through 1946.Earlier and more intensive tillage caused greaterlosses of soil N than later and less intensivecultivation.

1918-1945. Green manure crops did not benefitwinter wheat production. Their use of soil waterovershadowed any value they might have had.

1945-1954. Removal of crop residues by burningreduced water infiltration, increased winderosion hazard, and failed to increase averagewheat yields.

shed area and the remaining one-third for alevel bench terrace. Because more runoff wateris impounded on the bench, crops could begrown there yearly, while a conventional rota-tion, like wheat-sorghum-fallow, was employedon the slope.

1964-1977. Sorghum fertilized with eight plant-nutrient elements had the greatest yield re-sponse to applied N. Measuring nitrate-N in thetop 12 inches of soil showed that sorghum on100% of the sites responded to applied N whennitrate-N was less than 4 ppm, 66% of all sitesresponded when nitrate-N was 4-8 ppm, and43% had higher yields when nitrate-N levelswere greater than 8 ppm. Nitrogen fertilizerincreased wheat yields on 58% of all sites, addedphosphorus (P) increased wheat yields on 33%of all sites, and all other plant-nutrient elements(potassium, sulfur, zinc, iron, manganese, andcopper) increased wheat yields by 17% or less.

1964-1978. The level of soil nitrate-N had aneffect on yield response to added N. Yieldincreases were highest when soil nitrate-N levelswere less than 7 ppm. Yield increases were lesswith increasing amounts of soil nitrate-N.

1965-1977. Sorghum yield increases were notsignificantly different with fall, spring, or plant-ing N applications. However, significant yielddecreases resulted from early and late side-dressN applications.

1965-1977. Ammonium nitrate, urea, liquid N(UAN), anhydrous ammonia, and ammoniumsulfate fertilizers had no effects on sorghumyield. Results showed that all N-containingmaterials should be injected into the soil orincorporated with tillage tools. The advantageof using anhydrous ammonia was that it couldbe applied with various tillage tools, thus weedcontrol, seedbed preparation, and fertilizerapplication could be accomplished in one fieldoperation. Liquid N could be applied withcertain herbicides and in a single spray applica-

Rain water is held with furrow diking using a bain lister.

1948-1957. Tillage on the contour significantlyincreased wheat and sorghum yields more thannon-contour tillage.

1950-1958. With continuous cropping or oneroded soils, when surface and subsoil waterlevels were adequate, profitable increases inwheat yields were obtained when 30 lb N/a wasbanded with the seed at planting.

1958-1960. The Zingg conservation bench-terracesystem utilized two-thirds of a field for a water-

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tion. With a 2-inch buffer zone between the seedand fertilizer, the total N needs could be appliedusing liquid or dry N fertilizers.

1965-1977. Sorghum on only 33% of sites testinglow in available P responded to added P, andsorghum on 17% of sites showed a significantyield decrease. With increasing soil P levels,yield increases were mixed, whereas yielddecreases were significantly greater. The highestyield increase resulted when soil P and added Plevels were low.

1965-1978. Wheat grain protein decreased withincreasing yield levels. However, increasinglevels of applied N significantly increased grainprotein. Differences in protein among applica-tion times and N carriers were small. Spring-applied N often increased grain protein regard-less of yield.

1965-1978. Depth of moist soil had less of aneffect on wheat yields than grain sorghum yields.With application of an N+P combination to thewheat crop, 60% of the sites had yield increaseswhen depth of moist soil was less than 36inches, whereas 76% of the sites had yieldincreases when depth of moist soil was greaterthan 36 inches. When only N was applied, yieldincreases ranged from 46% to 64% with increas-ing depth of moist soil. When N carriers wereeither incorporated or injected into the soil,

only modest wheat yield differences occurred.Wheat yields with all N carriers were signifi-cantly higher than the control. Because the long-term precipitation average was only 22.5 inches,leaching of applied N was usually not a problemat Hays. Wheat also responded to added P whenavailable soil P levels tested 25 pounds or less.Banding P with the seed at planting resulted insignificantly higher yield increases than broad-casting and incorporating. Nearly twice as muchP was required with broadcast application toequal the yield response from P banded with theseed. Because wheat continued to show yieldincreases up to 46 lb P applied per acre, theeconomic return depended on the input costand price of the commodity.

1965-1996. In a wheat-sorghum-fallow rotation(W-S-F), crops were planted under clean-,reduced-, and no-till and fertilized with four Nlevels. They responded best to available soilwater supplies when grown under reduced-tillwith 60 lb N/a. Yields of both crops correlatedbetter with nitrate-N at the 6-inch depth thanwith ammonium-N or total N.

1965-1997. Soil samples taken in a W-S-F studywith three tillage systems and four N levelsresulted in some interesting findings. Instead ofdecreasing as expected, soil pH increased. Soilorganic matter did not change significantly overthe duration of this study. Available P washighest near the soil surface for no-till but atdeeper depths for clean- and reduced-till.

1966-1977. When soil moisture in the seedingzone was adequate for seeds to germinate, Nlevels up to 30 lb/acre (using ammoniumnitrate and liquid N) applied with the seedincreased sorghum yields, even though plantpopulation decreased significantly with increas-ing N rates. When soil moisture levels weremarginal to low, significant yield decreasesresulted from N applied with the seed.

Wheat showing a visual response to commercial fertilizer.

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1966-1978. Forty lb N/acre applied to sorghumincreased water use efficiency in terms of yieldresponse over the control by 16% and net returnper inch of water used by $1.07 when averagedon 90 sites located on- and off-station. Water-useefficiency on wheat from added N+P fertilizerincreased with increasing depth of moist soil, asshown by the higher yield and greater dollarreturn per inch of water used.

1967-1976. Yield response to ammonium nitrateor liquid N applied with the wheat seed wassignificant up to 40 lb N/acre. However, agradual decrease in plant population occurredwith increasing N levels.

1967-1977. Depth of soil water had an effect onsorghum yields and water use efficiency. When

the depth of soil water was 36 to 72 inches,response to added N increased significantly.When depth of soil water was less than 36inches, modest to insignificant yield increasesresulted. Water use efficiency increased as thedepth of soil water increased.

1969-1976. Yields of winter wheat were similarwith N applications at preplanting, planting, inthe fall (after emergence), and in the spring.

1969-1983. When starter fertilizer (N/P combi-nation) was band applied with the seed to soilstesting 25 lb or less available P per acre, signifi-cant wheat yield increases were consistent.

1970-1976. On soils testing 25 lbs or less ofavailable P, several phosphate carriers resultedin significantly higher wheat yields than thecontrol. However, no significant yield differencesoccurred among carriers.

1970-1977. When the soil flowed evenly over theV-blade during the application of anhydrousammonia, little N loss occurred, probablybecause the ammonia attached itself to thewater and clay in the soil. Unless considerableplant residue or large soil clods were present,applying anhydrous ammonia 2- to 4-inches deephad a positive effect on the performance ofwheat and sorghum.

1970-2000. From 1970 to 1979, feedlot manurewas applied on each crop in a W-S-F rotation.Thus, a total of six applications of manure weremade for each phase of the rotation. Significantbuildups of soil organic matter, available P,exchangeable potassium, nitrate-N, and ex-changeable sodium occurred with increasingmanure rates. Yields from the highest rates (40and 80 tons/acre) exhibited a gradual decline inyield. Soil testing each year since manure addi-tions ceased has shown a gradual downwardtrend of the chemical analysis. Wheat andsorghum yields since manure additions ceasedare still depressed at the highest rates.

Liquid side tanks on the tractor and anhydrous tank on theV-blade tillage tool allow a dual application of nitrogen and

phosphorus fertilizer through tubes on the underneath sideof each V-blade.

Storing soil water for the upcoming summer crop starts withmaintaining crop residue over the winter months to catch snow.

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1971-2000. Continuous dryland grain sorghumconsistently responded to fertilizer N at 20 to 40lb/acre. The response to N depended on thedepth of moist soil at planting. Deeper depths ofmoist soil resulted in greater yield response tohigher N rates. Phosphorus additions did notincrease yields on soil that tested medium inavailable P.

1972-2000. Yield responses to five N rates(20,40,60,80,100 lb N/acre) on continuouswheat under reduced-till generally were corre-lated to soil water amounts. The 20 and 40 lbN/acre rates usually resulted in the highesteconomic return.

1974-1977. Summer and fall applications of Nusing anhydrous ammonia increased yields morethan spring applications before sorghum plant-ing. Early N applications leached beyond the topfoot or so of soil that normally dries out duringthe hot summer months and, thus, was availablefor plant use. Disulfoton 15% granules at 0.56 kgAI/ha produced a statistically significantincrease in sorghum yields. The increase couldnot be attributed to insect, mite, or diseasecontrol. Possible explanations included: reduc-tion in soil nematodes, nutritional ingredients inthe insecticide, and an effect on some enzymesinvolved with plant metabolism.

1975-2000. Five crop rotations including wheatand sorghum under reduced- and no-till systems

were compared. Continuous sorghum gave thehighest average return per acre over the 25-yearperiod. W-S-F was a close second, whereas W-W-W, W-F, and S-F were significantly lower innet return.

1977-1981. Annual banded rates of concentratedsuperphosphate over a 5-year period resulted inhigher wheat yields than an equivalent one-timebroadcast rate. However, annual banded rates of92 and 184 lb P/acre significantly depressedyields. Wheat yield did not differ with one-timepreplant-banded applications of 230 lb P at 10-and 20-inch spacings over a 5-year period.Phosphorus applied 5 inches deep resulted inhigher wheat yields than that applied 10 inchesdeep.

1977-1994. Planting sorghum 2 to 3 weeks laterthan normal (June 10 to June 25 versus May 20to June 10), planting in 10-15-inch rows insteadof 30-inch, seeding at about three times thenormal seeding rate (90,000 instead of 30,000seeds/acre), and using one maturity groupearlier than normal resulted in rapid develop-ment of crop canopy over the soil, significantweed depression, even maturity, higher yieldsthan conventional methods, and effectivegrazing. Planting date and seeding rate for this“Superthick” method were heavily dependent ondepth of moist soil at planting. Producers areable to use their grain drills to accomplish thismanagement procedure.

1977-1994. Winter wheat varieties differedslightly in their ability to utilize soil N to in-crease grain production and grain protein. Thisfinding indicates that new variety releases mayneed to be screened for N-use efficiency.

1978. Grain protein of nine wheat varietiesincreased significantly with late May foliarapplications of three N rates (5, 10, 15 lb N/acre). When the market pays the producer forprotein, this procedure may become a soundmanagement practice.

Wheat growing in no-till sorghum stalks.

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1981-2000. Downy brome and other weedsresulted in moisture loss in continuous no-tillwheat. Without coulters, dragging of wheatstraw was common. Yields were reduced, andnumerous skips in stands were observed.

1983-1985. Seeding wheat and applying anhy-drous ammonia at the same time on the samehorizontal plane with a V-blade proved success-ful only when surface soil moisture was ad-equate and maximum pressure was applied tothe packer wheels.

1984-1985. Growing resistant sorghum hybridsin thick stands (superthick sorghum) keptsorghum greenbug infestations below the eco-nomic injury level. Any practice resulting indecreased plant populations densities couldintensify the greenbug problem on sorghum.

1984-1993. Sunflower planted in 12-inch rowsat three to four times the conventional seedingrate produced similar yields to that planted in30-inch rows at 15 to 20,000 seeds/acre. Appar-ently, sunflower has a great ability to adjust torow spacing and seeding rates. Sunflower headswere smaller where plant populations were high,but the number of heads per acre compensated.

1985-1992. Spring cereals (oats, barley, andwheat) exhibited higher yields when N/Pcombinations were used than when N or P wasapplied separately. Because of reduced tilleringcompared to cereals seeded in the fall, springcereals exhibited higher yields when nearly twicethe conventional seeding rate was used.

1985-1994. Narrow row spacing (6 inch) wassuperior to the conventional 12 inch only inyears when surface soil moisture was slightlyabove average. Wheat seeded in both rowspacings responded similarly to N fertilizer. Highseeding rates had little effect on grain produc-tion, whereas the low seeding rate of 0.5 bu/acre reduced yields.

1985-1995. Although the yield differences ofsoybeans between row spacings were small, theywere consistent enough to favor a 24-inch rowspacing regardless of variety or seeding rate.Late maturity group II or maturity group IIIhad consistently higher yields than maturitygroups I and IV. Seeding rates tended to favor140,000 to 150,000 seeds/acre.

1986-1992. Grain sorghum when mowed off atthe late vegetative stage to simulate severe haildamage grew back and produced a crop slightlybelow to slightly above that from the unmowedplots. Although maturity was delayed by mow-ing, this study showed sorghum’s great ability toproduce a significant crop in spite of haildamage.

1986-2000. Seventeen fertilizer variables wereincorporated into a W-S-F study under clean-,reduced-, and no-till systems. On a highly erodedsoil, wheat and sorghum grown under no-tillhave performed well. This is noteworthy be-cause on more level, higher fertility soils, wheatin reduced-till has performed the best. Bandplacement of N fertilizer on wheat and sorghumprovided yields equal to or higher than thosefrom twice the N rates surface broadcast.

1988-1990. Winter-associated changes in dry-soilaggregation as influenced by clean-, reduced-,and no-till systems were studied. Aggregates

In the foreground 20 lb N/a banded with the seed compared tothe control immediately behind.

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from plots with low residue cover decreased instability more than aggregates from high-residuetreatments. Differences in aggregation betweentillage systems were maintained during a drierwinter and minimized during a wetter winter.Studies also showed that insufficient residueproduction for wind erosion control in the no-till system could lead to more erodible condi-tions than in clean- or reduced-till systems.

1989-1991. Liquid starter fertilizer 10-34-0banded with the seed increased wheat yields upto a rate of 15 lb N combined with 51 lb P2O5/acre. Yields tended to level off thereafter. Whenanhydrous ammonia was applied at seeding time(about 2 inches below the seed), N rates over 30lb/acre reduced wheat stands and yields.

1990-2000. For the first 5 years, shreddednewspaper and grass clippings were spread viahand and a manure spreader at rates of 5, 15,and 45 tons/acre. Some combination treatmentsincluded both newspaper and grass. Croppingsystems were dryland forage sorghum-fallow andirrigated, continuous forage sorghum (water washauled to specific designated plots). Becausenewspaper is devoid of N and grass is high in N,the combination treatments have performedwell. Since the first 5 years, the soil has beenmonitored for carbon (C) and N. Only in thelast 2 years have we been unable to read theprint on the newspaper, particularly at the hightonnages. The microorganisms are graduallydecomposing the newspaper, but it will take

several more years to reach a 12:1 C/N ratio.

1991-1993. Wheat seeded within multiples of 4-second intervals after applying various N ratesof anhydrous ammonia exhibited minor standand yield depressions. At the 50 lb N/acre rate,yield increases were noted, especially at 12- and16-second intervals. Apparently, anhydrousammonia ties itself very quickly onto water orclay in the soil.

1992-2000. Strategies were developed for smallgrain forage (triticale, rye, and wheat) thatprovided profitable grazing, haying, and grainproduction. Rye had more grazing potential inthe fall through the late winter months whereastriticale performed well in March, April, andMay. Wheat had the poorest performance.

1994-1998. Pearl millet and grain sorghum wereused in a study where row spacing, plant popu-lation, and seeding date were compared. In allcomparisons, grain sorghum yielded more thanpearl millet. The best pearl millet yields werefrom 12-inch rows at a high seeding rate. Dateof planting had little effect on pearl millet yields,but the later planting did favor the grain sor-ghum yields when planted in narrow rows at ahigh seeding rate.

1996-2000. Use of cross-linked polyacrylamidesin combination with banded fertilizer provided asynergistic effect on the grain yields of wheatand grain sorghum. High humidity and flow inthe distribution tubes sometimes were problemswith the granular polymers. Finely groundpolymers when blended with liquid fertilizersdid not gel in the tank but did significantlyincrease yields over fertilizer alone. This study atHays was the first test of such blends with finelyground polymers.

1998-2000. When the same hybrid was used, Btcorn significantly outproduced non-Bt corn,regardless of plant population or row spacing.

Spreading 45 ton/a of shredded newspaper by handon a 24' by 30' plot.

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Sorghum Research, Kenneth D. Kofoid, Sorghum Geneticist

Research dealing with sorghum started with the establishment of the Fort Hays Branch Experi-ment Station. Sorghum occupied 27 acres of land during the first year of research. Most of thework was carried out by employees of the USDA in cooperation with the state experiment sta-tions, and research was established on a region-wide basis that included the entire sorghum belt.

1902-1920. Because sorghum was important asboth a forage and grain, most of the researcheffort was directed towards adapting culturalpractices to maximize both grain and forageyields. B.E. Rothgeb (grain) and R.E. Getty(forage) were two of the scientists stationed atHays that participated in this work. Theirresearch included experiments with differentcultivars, dates of seeding, rates of seeding,weed control, row spacing, harvesting of forageand grain, and handling of seed. They were ableto demonstrated that sorghum was extremelyversatile and that plantings could be done fromMay to July, that row spacing could be variedfrom drilling to 80 inches between rows, andthat within-row plant spacing could vary from 2to 8 inches with little change in forage or grainyield. Varietal improvement was another compo-nent of the research, and during this time, PinkKafir was released for grain production, andRed Amber was released for forage production.Pink Kafir remained an important cultivar formore than 20 years.

1921-1930. Hybridization of existing sorghumlines to develop new varieties was begun byArthur F. Swanson. This effort resulted in therelease of Modoc, Dwarf Freed, and Kalo grainsorghums and Early Sumac forage sorghum. Healso determined that differences in germinationamong cultivars were related to the seed coatand its influence on water absorption. Studiesconfirmed the genetics of seed color.

1931-1940. Varietal improvement continued withemphasis placed on combine-height sorghums.New cultivars released included Club Kafir andEarly Kalo. Studies determined the relationshipsof seed size and germination to plant stand.

Because of the drought years, a conditionknown as “weak neck” developed. Studies wereconducted to determine the genetic inheritanceof smut resistance, stalk juiciness, and awns.

1941-1950. A new type of sorghum was devel-oped and released in response to the war. Codysorghum contained a waxy endosperm, and thestarch was used as a replacement for cassavastarch. This line also was the first to be grownunder contract as an identity-preserved line thatgarnered a premium in price. Other graincultivars released included Midland and Gurnoand forage lines released were Norkan, Ellis,Kansas Sourless, and Kansas Collier.

W.M. Ross makes hand-emasculated crosses in greenhouse.

1951-1960. The decade saw major changes insorghum research at Hays. William M. Ross tookover the breeding effort, and hybrid sorghumsreplaced cultivars. Development of parentallines and testing of hybrids rather than cultivarsbecame the objective. Cultivars that had beendeveloped were converted to either cytoplasmicsteriles or restorer lines. Research was con-ducted to study various aspects of hybrid seed

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production. Stigma receptivity in male sterileswas studied to determine the length of time thatfemales remained receptive to pollen. Interge-neric crosses were made, and triploids wererecovered. These triploids then were used toidentify genes. In an attempt to produce largerseeds, tetraploid grain sorghums were devel-oped. Agronomic studies were conducted todetermine effects of border rows on plot yields.These studies allowed sorghum breeders to workwith smaller plots and still produce valid results.

1971-1980. In an attempt to broaden the cyto-plasmic sterility base of sorghum hybrids, sixnew sources of cytoplasmic sterility were devel-oped and released (KS 34-KS 39). In addition,five new male parent lines and one new femaleparent were released. In response to the yearlygreenbug infestation, more than 10,000 acces-sions were screened for greenbug resistance.From this number, only 21 new sources ofresistance were identified. Because of theappearance of viral epidemics, inoculationprocedures were developed to screen for maizedwarf mosaic virus (MDMV) and sugarcanemosaic virus (SCMV). With the ability todetermine resistance, we were able to developand release lines with tolerance to MDMV andSCMV (KS 55-KS 56).

1981-1990. Johnsongrass mosaic virus wasidentified as a new pest of sorghum, and screen-ing techniques were expanded to include thisdisease. A new immunological technique wasdeveloped to correlate virus titer with toleranceto SCMV. Other studies noted the correlationbetween yield loss and virus titer in hybridsinfected with SCMV. Research showed thatgreenbugs were attracted to clean-tilled fields,thus furthering the use of conservation tillageprocedures. After the untimely death ofHackerott, Kenneth D. Kofoid assumed leader-ship of the sorghum breeding project. With thepresence of a new biotype of greenbug, morethan 10,000 additional accessions of sorghumgermplasms were screened for biotype E green-bug resistance, but only seven new sources ofresistance were found. A new method to infestplants with greenbugs using a mechanical insectdispenser was developed. With these newscreening techniques available, germplasm withresistance to greenbug biotype E (KS 85-KS 93)sometimes combined with tolerance to MDMVand JgMV (KS 85); tolerance to MDMV andSCMV (KS 90); and tolerance to MDMV,SCMV, and JgMV (KS 93) were developed andreleased.

H.L. Hackerott evaluates sorghums for resistance tomilo disease.

1961-1970. The major research effort of thisdecade was the development of parental linesand the testing of hybrids. Releases includedfour restorer lines (KS 2, KS 4, KS 19, and KS20); three cytoplasmic steriles (KS 4, KS 22, andKS 23); and four hybrids (KS 602, KS 603 KS651, and KS 701). These lines were among thefirst to add the yellow endosperm trait tocommercial sorghums. Several of these releasesare still being used to add drought tolerance topresent-day germplasm. Following the move ofRoss to Nebraska in 1969, Harold L. Hackerotttook over leadership of the sorghum project.That same year, the greenbug was identified as amajor pest of sorghum. Screening of germplasmin the field resulted in the identification andrelease of the first germplasm line with resis-tance to greenbug biotype C (KS 30).

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1991-2000. Further changes in the greenbugwere identified as biotypes I and K. Screeningof available germplasm against biotype I green-bug showed that all but two germplasms weresusceptible. In response to this, KS 96 withresistance to biotype I, was released. Newgermplasms with biotype E greenbug resistance(KS 99-KS 107) as well as with biotype I resis-tance (KS 108-KS 114) were released. Easterngamagrass was identified as a perennial host forSCMV, thus showing how the disease couldoverwinter. Natural infections of sorghum byfoxtail mosaic virus and wheat streak mosaicvirus were recorded. Zea mosaic virus and threenew viruses also were identified, and broad-scalescreening techniques were developed to test forall sorghum-infecting viruses.

Greenbug biotype determination.

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Weed Management Research, Phillip W. Stahlman, Weed Scientist

Weed research has focused on weed problems in dryland cropping systems in western Kansas.However, many findings proved applicable to major portions of the western United Statesand in similar environments internationally. This compilation reveals three major areas ofemphasis that developed over the years.

• Research during the first half of the century emphasized control and management of fieldbindweed through use of intensive cultivation, competitive crops, salts, and persistent chemi-cals.

• Starting in 1945, the emphasis shifted to testing and developing selective herbicides for use inwinter wheat, grain sorghum, and fallow. Dryland corn, sunflower, and soybean were added inthe 1990s. Herbicide evaluation and development remain important areas of research.

• Evaluating alternatives to chemical herbicides, determining economic control thresholds, anddeveloping integrated weed management systems were emphasized in the 1980s and 1990s.

1907. The Kansas Legislature appropriated $1000for experiments to eliminate field bindweed.Results of experiments conducted for 2 years onprivately owned land near Victoria showed thatwith winter plowing and proper use of smothercrops such as sorghum or kafir, field bindweedcould be destroyed or at least weakened. Also,field bindweed was destroyed with high quanti-ties of salt or brine, but nothing grew on treatedareas for several years.

1915-1930. Experiments using salt, intensivecultivation, and smother crops were initiated byR.E. Getty, leader of the cooperative Federal-State Project on Forage Crop Investigations.Field bindweed control research was continued

as part of the Forage Crops project until about1930. Applications of salt made in 1919 werestill affecting crop production adversely into the1960s.

1935. The U.S. Department of Agriculturestarted a field bindweed control project at Haysunder the direction of F. Leonard Timmons.This cooperative federal-state project, one ofseveral begun in the Great Plains, was theformal beginning of the Weed InvestigationsProject at Hays.

1935-1950. Extensive, highly detailed, cultural-control experiments using intensive cultivation

F.L. Timmons sprays field bindweed in 1936. F.L. Timmons and assistant pick bindweed roots from soil in 1936.

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and competitive cropping systems were con-ducted. The effects of cultivation depth andfrequency on bindweed’s root system and rootfood reserves were documented, and studieswere initiated and continued by others showingthat bindweed seeds can remain viable in thesoil for more than 50 years.

1945. Timmons was one of the first civiliansallowed to test 2,4-D, and he conducted numer-ous experiments investigating its use for controlof bindweed and broadleaf weeds in winterwheat. His studies and subsequent work deter-mined that 2,4-D would not eliminate fieldbindweed under most conditions, but it washighly effective especially when combined withintensive cultivation and competitive crops.

1948. William M. Phillips succeeded Timmons asproject leader. He scaled back research on fieldbindweed control and broadened the scope ofresearch to include control of annual weeds inwinter wheat, grain sorghum, and fallow.

1950s. Several new preemergence herbicides wereevaluated and developed for selective weedcontrol in grain sorghum, including atrazine,norea, propachlor, and propazine.

1951. Recommended intervals between cultiva-tions were reported to be 18 to 20 days for fieldbindweed, 4 weeks for johnsongrass, and at least3 weeks for hemp dogbane and Russian knap-weed. Studies showed no advantage for cultivat-ing deeper than 3 to 4 inches.

1958. Culmination of severl years researchresulted in recommended uses of 2,4-D in grainsorghum and identified associated risks. Amineformulations were less injurious than esterformulations. Excavations revealed that roots ofkochia plants growing on an upland soil pen-etrated as deep as 10 ft, had a lateral spread ofup to 8 ft, and depleted moisture to the perma-nent wilting point to a depth of 6 ft.

1961. A USDA bulletin was published summariz-ing 24 years of field bindweed control researchat the Fort Hays Branch Experiment Station.

1964 & 1969. Phillips published pioneeringresearch that enabled farmers to combineherbicides with minimum tillage for weedcontrol during fallow after wheat harvest andprior to planting grain sorghum in a winterwheat-sorghum-fallow rotation. This systemreduced the number of tillage operationsneeded, increased soil moisture storage, substan-tially increased grain sorghum yields, andreduced risks of soil erosion. Additional re-search refined and improved the system. Varia-tions of the original concept were adoptedwidely and remain in use into the 21st century.

1967. Applying 2,4-D to winter wheat was foundnot to affect the milling quality of the grain orbaking quality of the flour.

1972. Phillips began evaluating glyphosate(Roundup®) for use in reduced tillage andfallow systems.

1973. The U.S. Department of Agriculture endedsupport of the Weed Investigations Project atHays. The state of Kansas assumed full supportof the project, and Phillips left USDA to con-tinue as project leader.

1974. A loss of herbicidal activity was observedin field experiments when glyphosate was tankmixed with atrazine and/or propachlor (Ram-rod®) herbicides.

1975. Studies were initiated to determine theeffects of water quality, spray volume, and tankmixing with other herbicides on glyphosateefficacy.

1976. Phillips was appointed Acting Superinten-dent of the Fort Hays Branch Experiment Station.Phillip W. Stahlman succeeded him as leader ofthe weed control program. The name waschanged to the Weed Control Research Project.

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1977. Evaluationsbegan of two ex-perimental com-pounds, DPX-4189 and DPX-T6376, belongingto a new class oflow use-rate herbi-cides for use inwinter wheat.Eventually, theywere registered asGlean® andAlly®, respec-tively, and repre-sented the first ofseveral sulfony-lurea herbicides.

1985. Studies showedthat downy brome,cheat, and Japanesebrome, commonlyreferred to collec-tively as cheat orcheatgrass, were notcontrolled equally bydiclofop (Hoelon®)herbicide. Subsequentresearch demon-strated differentialresponse to otherherbicides as well.

1989. Stahlman beganinvestigations on theuse of indigenous soilbacteria for selective

Former scientist and Branch Stationhead Bill Phillips inspects wheat

stubble in reduced-tillgrain sorghum.

1979. Stahlman continued Phillips’ work, andthey coauthored two of the first peer-reviewedscientific papers on factors affecting glyphosateactivity. These publications were cited fre-quently and led to changes in use recommenda-tions that improved glyphosate performance.

1980s. Anticipating that weed problems in winterwheat would increase with adoption of conser-vation tillage and semidwarf wheat cultivars,Stahlman conducted numerous studies todetermine economic control thresholds ofdowny brome in wheat. He also intensifiedtesting of experimental herbicides for control ofbroadleaf and grass weeds in wheat.

1984. Stahlman took sabbatical leave and anunpaid leave of absence to work towards a Ph.D.in Weed Science at the University of Wyoming.He continued to direct research at Hays bycommunicating frequently with Research Tech-nician Douglas A. Schneweis and by traveling toHays periodically. He resumed full-time, onsiteresponsibilities in 1986 and completed his Ph.D.in 1989.

Inhibiting root development of jointed goatgrass with abacterial isolate.

Inhibiting root and shootgrowth of Japanese bromewith a bacterial isolate.

control of winter annual grass weeds in winterwheat. Competitive grant funding allowed thehiring of a soil microbiologist, Pamela A. Harris,to facilitate the research.

1990. Field experiments in Kansas and Wyomingshowed that downy brome emerging within 14days after winter wheat at densities of 20, 30,and 50 plants per square yard reduced wheatyields by 10, 15, and 20% respectively. Downybrome emerging 21 or more days after winterwheat did not reduce wheat yield.

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1992. Studies in collaboration with scientists inColorado, Montana, and Wyoming concludedthat mixtures of 2,4-D plus picloram (Tordon®)at 0.125 or 0.25 lb/acre provided better long-term field bindweed control than 2,4-D,glyphosate plus 2,4-D or dicamba premixtures(Landmaster® and Fallowmaster®, respec-tively) or dicamba plus 2,4-D. A 4-year collabora-tive experiment began with scientists in threeother western states to determine feral ryeinterference and economic thresholds in winterwheat. Also, another 4-year collaborative experi-ment began with scientists in seven otherwestern states to develop regional, predictive,bioeconomic management models for jointedgoatgrass in winter wheat.

1992-1996. Feral rye was found to be morecompetitive with winter wheat than jointedgoatgrass, which in turn was more competitivethan downy brome. As few as 4 feral ryeplants/yd2 were enough to reduce wheat yield.

1993. Work at Hays helped identify the scope andthreat of jointed goatgrass leading to establish-ment of a USDA Research Initiative and subse-quent federal funding for a National JointedGoatgrass Research Program.

1994. A 3-year collaborative experiment beganwith scientists in three other western states todetermine the effects of wheat cultivar andseeding rate on jointed goatgrass interference inwinter wheat. Stahlman was one of the firstpublic scientist to evaluate MON 37500 forwinter annual brome control in winter wheat.The herbicide was registered as Maverick™ in1999. A U.S. patent was awarded for threebacterial isolates showing promise for selectivebiological control of downy brome, Japanesebrome, and jointed goatgrass in winter wheat.

1995. The first statewide survey on the extent ofwinter annual grass weeds in winter wheatindicated that winter annual bromes infested

13.2% of the 1994 Kansas wheat acreage, andjointed goatgrass and volunteer cereal rye werepresent on 2.3 and 5.3% of the acreage, respec-tively. Application method affected the popula-tion and distribution of biocontrol strains in thesoil and downy brome rhizosphere and influ-enced the efficacy of rhizobacteria for weedcontrol. The first evaluation of a geneticallymodified crop at Hays involved Roundup-Ready® soybeans.

1996. Purified bacterial isolates began losingbiocontrol effectiveness each time they werecultured, and attempts to restore originalactivity were not successful. Either the isolatesmutated or lost the ability or need to producegrowth-suppressive toxins when in purifiedculture. What initially appeared so promisingended in disappointment, and the project wasterminated. Tests showed that Japanese bromewas more susceptible to soil-applied Maverick™than cheat or downy brome, and jointedgoatgrass tolerated two to three times moreMaverick™ than the bromes. A long-termintegrated study was initiated to assess theinteractive effects of crop rotation, wheatcultivar, and fallow weed-control method afterwheat on jointed goatgrass management. Thefirst field experiment was conducted demon-strating the potential of sulfentrazone for weedcontrol in sunflower. The herbicide was regis-tered as Spartan® for use in sunflower in 1999.

1997. Research indicated that foliar injury of upto 50% caused by applying urea-ammoniumnitrate (UAN) alone or as a carrier for herbi-cides in spring did not reduce winter wheatyields. Adding nonionic surfactant (NIS) to theUAN solutions increased foliar injury, anddiluting UAN 50% with water lessened foliarinjury, especially in the presence of NIS. Foliarinjury was related inversely to temperaturefollowing application. The first evaluation wasconducted of genetically modified corn resistantto glyphosate. A field experiment was done to

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demonstrate the potential of imidazolinoneherbicide-tolerant winter wheat for control ofwinter annual grasses. This represented the firstknown successful selective control of jointedgoatgrass and feral rye in winter wheat. Studiesshowed that critical periods of longspine sand-bur interference in dry corn and grain sorghumwere 3 and 4 weeks, respectively.

1998. Maverick™ controlled downy brome bestwhen applied preemergence or fallpostemergence compared with springpostemergence application. A satellite weed

science project was established at the NorthwestResearch-Extension Center in Colby, and thefirst weed control experiments were conductedin dryland corn. A long-term field experimentwas initiated to monitor shifts in the weedspectrum and assess potential risks associatedwith the continuous growing of glyphosate-resistant crops.

2000. The first evaluation was done of geneticallymodified winter wheat resistant to glyphosate.

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Wheat Research, T. Joe Martin, Wheat Breeder

1901-1940. The wheat research program at theHays Station began very early in its history.Most of the early research dealt with improvingproduction pra