Embed Size (px)
Citation preview
Volume 9, Issue 20 August 14, 2013
Cooperative Extension Cornell Vegetable Program
Cornell University
We
ek
ly
Ve
g E
dg
eV
eg
Ed
ge
Ve
g E
dg
e
Contents Dates .................................................................................. 8
Sponsors ............................................................................. 9
Weather Charts .................................................................. 9
Crops Crops: Tidbits & Insights ............................................... 4-5 Onion: Brassica Cover Crops ............................................ 3 Potato/Tomato: Late Blight Risk ...................................... 6 Sweet Corn: Reduced Ear Size Problems ......................... 7 Sweet Corn Trap Network Report, 8/13/13 .................... 5 Tomato: Refuse/Resist: Late Blight vs Septoria ............... 1 Tomato: Stink Bug Damage ............................................ 6
Refuse/Resist: Late Blight vs. Septoria by Judson Reid, Cornell Vegetable Program
continued on page 2
Much is made of the threat of Late Blight to tomato crops, with just cause. However, the furor over this disease overshadows the threat of others that can be equally destructive. In 2013 this juxtaposition can be seen with Septoria Leaf Spot. Although Late Blight is present and will continue to spread in NY this season, Septoria will likely cause greater economic loss.
The epidemiology of Septoria has been covered previously in this publication, but in sum-mary; it is a soilborne, overwintering fungus on tomato debris that causes leaf spots and defoliation. This seems like a bore compared to the elusive ‘blown-in’ mystique of Late Blight, which keeps tomato growers (and Extension) jumpy; with its unpredictable death-fog spread.
Septoria blight of tomatoes. Photo: Judson Reid, Cornell Vegetable Program
continued from cover - Refuse/Resist: Late Blight vs. Septoria
Volume 9, Issue 20 August 14, 2013 Veg Edge Weekly
Page 2
Since Late Blight doesn’t overwinter on dead plant tissue in NY, it maintains a guest-appearance status. Septoria, on the other hand begins annually with spots lower in the canopy, often mixed among natural senescence, leaf curl, magnesium deficiencies and Early Blight.
When Late Blight hits the loss is sudden and total. However, the following year presents a fresh slate for the disease. Septoria is more insidious as it can overwinter on used stakes. We recommend a 3-year rotation away from tomatoes to reduce the disease in the soil. In 2013 several growers did just this, but didn’t disinfect used stakes, es-sentially eliminating any benefit from rotation by manually reintroducing inoculum. Thus manage-ment of the disease is task oriented: Stake and mulch to reduce soil splashing
Disinfect stakes
Rotate soils
Grow resistant varieties
The final bullet is the only one shared with Late Blight management, but is an important new management tool. Excellent resistance can be found now in the Cornell developed variety ‘Iron Lady’ and Jasper (cherry-type). The difference between resistant and non-resistant varieties can be easily observed, particularly where no fungi-cides are used (see resistant vs susceptible varie-ties photos). Although the value of heirloom vari-eties is widely recognized, all growers stand to benefit from disease resistant varieties.
In summary, comparing Late Blight to Septoria (and other ‘every year’ foliar diseases); we ob-serve a reaction similar to transportation/fatality risks. Air travel causes fewer fatalities than auto-mobiles; however plane crashes generate greater media attention than the thousands of daily wrecks on the highways. Management is also less heroic for annual tomato diseases. Instead of donning spray suits and resorting to expensive oomycete materials, managing Septoria is done with a pencil; steadfast planning and implementa-tion of simple measures such as rotation, sanita-tion and variety selection. The result for these farmers will be a crop with full canopy and fruit yield. Others will continue to worry that Late Blight might blow in on the next thunderstorm and kill the last remaining leaf on a Septoria in-fested plant.
Septoria leaf spot on a tomato leaf (left) versus late blight on a tomato leaf
(right). Septoria photo: Judson Reid, CVP; Late blight photo: Meg McGrath, Cornell
Septoria susceptible variety (above) versus Septoria resistant variety (below). Photos: Judson Reid, CVP
August 14, 2013
Brassica Cover Crops in Onions
C. Hoepting, CVP: In recent years, a few onion growers have experimented with various cover crops from the Brassica family including mustards and tillage/forage radish. So far, growers have been happy with the results sighting improved drainage and a very good onion crop the following season. More in-depth studies of the use of Brassica cover crops in onions on muck are planned by the CVP. The key is that they need to be planted in August in order to achieve enough biomass be-fore they are winter-killed, and are only suitable following onions that are har-vested early.
Tillage/Forage Radish to Improve Drainage: Tillage or forage radish is a fall Brassica cover crop that have tap roots that drill deep where steel can’t reach (Fig. 1). These thick, white tap roots can reach lengths of 8-14”, most of which are underground. A thinner extension of the tap root can penetrate deep layers of compaction. The crop winter kills and the tap roots decompose quickly leaving deep channels for air to enter into the soil and for water to drain. While growing, the deep tap roots scavenge soil nitrogen that has gone below the crop root zone. Other ad-vantages include wind erosion control in the fall, weed suppression in the following year’s crop, and minimal crop residue that allows for very early planting the following spring. The planting window is now! – during the month of August, ideally by August 10th to get enough biomass of tillage radish. Broadcast tillage radish at 8 lbs/acre and incorporate to 0.75 to 1 inch deep. Added fertility is not expected to be needed following onions on muck soil. The variety “Tillage radish” can be ob-tained from Bird Hybrids (Tiffin, OH; 800-743-BIRD; [email protected]), Kings Agriseed (Ronks, PA; 866-687-6224; [email protected]) and Lancaster Ag Supply (Ronks, PA; 717-687-9222; [email protected]). The variety “Groundhog” can be ob-tained from Seedway.
Mustard Cover Crops to Improve Stand and Yield in Next Year’s Onions: Studies conducted at Michigan State University by Dr. Mathieu Ngouajio reported that onion stand establishment and yield responded positively to brassica cover crops including yellow mustard and oilseed radish under muck soil conditions. Overall, onion stand was about 13% to 40% greater in the cover crop plots com-pared with the control without cover crop. With such increase in stand, the impact of the cover crops was either negative or minimal because the higher onion density in the cover crop plots resulted in too many small bulbs. However, as onion plant density decreased, the benefit of using the cover crops became more evident. The largest benefit of using the mustard cover crops was found at onion density of 172,000 plants per acre. At that density the impact of the cover crops was a 15% yield increase. Given the fact that many growers are currently using densities close to 220,000 plants per acre or more, it is evident that the cover crops could help reduce onion seed cost. Suggested reasons for improved stand establishment fol-lowing a fall mustard cover crop include increased nutrient cycling, especially of nitrogen, weed suppression and increased beneficial soil microorganisms. Also, soil-borne diseases may be suppressed by glucosinolates in the mustard residues.
Examples of varieties of yellow mustard in-clude Tilney (low glucosinolates) and Ida Gold (high glucosininolates), both from McKay Seed Company (http://mckayseed.com/index.html). Caliente 199 is a brown mustard from Rupp Seeds that some onion growers experimented with last fall, and plan to use again this year. Pacific Gold is another brown mustard variety from McKay Seed Company. Bonar (Fig. 2) and Rangi are varieties of rapeseed sold by Ernst (800-873-3321; http://www.ernstseed.com/, Measdville, PA). Mustards should be planted from mid-July through August, but not in Sep-tember. Following onions, mustard cover crops should have enough nutrients and not need anymore. Prepare a firm, weed-free seedbed. Drill 5-12 lb/A or broadcast 10-15 lb/A, depending on seed size. Kill the mustard when in flower and before it sets seed, and immediately incorporate the crop residues for disease suppressive benefits. The mustard will winter kill and leave little residue by spring. If some do survive the winter, be sure to kill it before the mustard goes to seed.
For more information, visit “Cover Crops for Vegetable Growers” website at http://covercrops.cals.cornell.edu/.
Figure 1. Tillage radish
grown in the fall following onions in the Elba muck. Photos: Christy Hoepting, Cornell Vegetable Program
Figure 2. Rapeseed, c.v. Bonar, grown in a strip trial in the Elba muck (11/22/11). Photo: Christy Hoepting, CVP
Volume 9, Issue 20 Veg Edge Weekly
Page 3
August 14, 2013 Veg Edge Weekly
Page 4
Volume 9, Issue 20
DRY BEANS The crop is progressing with many fields having a few full length pods. The latest fields could use more degree days than we’ve been having. A purple Western bean cutworm (WBC) egg mass, nearly ready to hatch, was found in a sweet corn field near LeRoy. Growers with dry beans near Attica, north of Bergen and Bellona, should spend some time looking for WBC eggs and small lar-vae in nearby corn fields as well, especially if corn is in the late whorl to early silk stage. Egg masses and recently hatched larvae will be found on the upper side of upper leaves. If found in corn, dry bean pods in nearby fields should be scouted in the next several days. If any feeding damage is found the field should be sprayed once with a longer-lasting pyrethroid insecticide. See additional photos in the 8/7 Veg Edge Weekly. From www.nass.usda.gov/ny 8/12/13: Dry bean production in New York is forecast at a record low 129 thousand hundredweight (cwt), down 29% from the 182 thousand cwt produced last year. Harvested acreage is expected to total a record low 7,800 acres, down 1,700 acres from 2012. U.S. dry edible bean production is forecast at 24.6 million cwt for 2013, down 23% from last year.
MELONS Multiple cases of Sudden Wilt of cantaloupe and watermelon have occurred in the region over the last two weeks. This disorder is associated with heavy fruit loads, cool nights, clear days and the presence of pathogenic fungi in the soil. As noted in earlier Veg Edge issues this season, mel-on crops developed excellent canopies, and in some cases, corresponding fruit loads. Fusarium and other fungal species survive for extended periods in the soil via overwintering spores as well as on decomposing plant tissue and may be non-pathogenic on some crops. The presence of these pathogens may not be evident until the canopy collapses. As the plant struggles to main-tain moisture supply to a heavy fruit load on a sunny day following a cool night, the fungaly com-promised root system cannot perform. The plant collapses, often overnight, or over the course of several days (see photo); leaving immature fruit exposed to the sun where they cannot mature properly. Distinguishing between straight Fusarium Wilt and Sudden Wilt in the field is challeng-ing; and somewhat inconsequential as management strategies are similar. Sudden Wilt may in-volve other pathogens such as Pythium and Rhizoctonia; but is more of a complex disorder than a simple pathogen-host effect. Rotation can help, but Fusarium is long lived in the soil. Thus disease resistant varieties are essential. Fusarium wilt species are often host specific in patho-genicity. In other words, the race that causes wilt on watermelon is not the same for cantaloupe. However, rotation away from all vine crops is still recommended for management of other diseases and insects. Fungicides are not a management option for this disease.
ONIONS It’s been awhile since we’ve seen the onion crop size up like this – week after week, the bulbs just keep getting bigger and bigger! Alt-hough the cool weather has favored bulbing, it is also delaying maturity and fields are going down slower than we’ve seen during the last couple of years. At this stage of the game, the crop could actually use a little bit more heat. If this continues the late-season varieties will not want to go down.
Onion thrips pressure was up slightly this week with highest pressure occurring at influx sites. As fields are pulled, the thrips are moving out of the harvested fields and into nearby fields that are still standing and green. There are a lot of adult thrips on the onion plants. Many growers are using Agri-Mek and Radiant. Agri-Mek has a 30-day pre-harvest interval, and harvest is defined as when the onions are picked up out of the field. Therefore, if you are planning on picking up your onions prior to August 15th, it is too late to use Agri-Mek. If you have already used two applications of Radiant, you should rotate away to a different chemical class for resistance management. Radiant is the most effective insecticide that we have that can be used at this time of year, and it is critical that it is not over-used and abused or else thrips populations will become resistant to it. Lannate or one of the pyrethroids such as Warrior may be used after the second Radiant. Radiant has a maximum limit of 30 fl oz per season, so technically, a third Radiant may be applied after rotating to a different chemical class for at least one week.
Purple Blotch is the major leaf disease in onions right now with Botrytis leaf blight being hard to find at this point. Several fungicides for PB are labeled in onions including Scala, Quadris and Rovral. Note that Bravo and mancozeb are weak against PB. Quadris needs to be alter-nated with a different mode of action and may be used up to four times (at the high rate) per season. Despite favorable conditions of cool nights into the 50s and heavy dews, there have been no new reports of downy mildew, although old and dried up infections are evident. None-the-less, mancozeb, phosphoric acid or Quadris should be included in the tank mix as a preventative measure against DM.
Brassica cover crops continue to be grown on more onion ground, but they need to be planted in August. The optimal planting date for tillage/forage radish is August 10 in order to accumulate enough biomass. Other mustards can be planted anytime in August – see pg 3.
Thank you to the 35 onion growers and allied industry representatives who participated in the Annual Elba Muck Onion Twilight Meeting last Thursday – as always, it is our pleasure to educate! Check out the article in Batavia Daily News: http://thedailynewsonline.com/news/article_f04dedd8-016f-11e3-a1a9-0019bb2963f4.html.
Muck Donut Hour Closed for the Season – Thank you to all the growers and special guests who make muck donut hour on Tuesday morn-ings in the Elba muck “a whole lot more than just donuts!”
CROPS Tidbits & Insights
Sudden wilt fusarium of cantaloupe. Photo: Judson Reid, Cornell Vegetable Program
WBC eggs turning purple, right before hatch. Photo: J. Obermeyer, Purdue
Attention Onion Grower Cooperators of Re-search Trials: Most of our on-farm research trials that are underway will need to be har-vested this year. Our goal is to collect our harvest data before you pull the onions. When we are finished with our trials, we will pull all stakes and flag markers. Please check with Christy before you pull the onions in any trials with stakes and flags remaining. Your cooperation is much appreciated!
POTATOES More vine killing of early fields is occurring. Any fields where you suspect pink rot may be a problem should be harvested last, so infect-ed tubers have time to break down in the field, and should be sold first. Many small to medium Colorado potato beetles (CPB) have been seen in some fields. If you used a sys-temic insecticide seed treatment or in-furrow treatment at planting (all materials in the same Chloronicotinyl Class) be sure to use a material in a different class at this time, such as Coragen, Voliam Xpress, Radiant, Black-hawk, etc., or Entrust for organic production. For more info, see the 2013 Cornell Vegetable Guidelines at: http://veg-guidelines.cce.cornell.edu/24frameset.html
Taken from Phil Nolte and Nora Olsen, U of Idaho, “What is Skin Set and How Do We Achieve It?” Good skin set is essential to re-duce bruising and subsequent decay, and to reduce shrink during the early storage sea-son. The fully set “skin” or periderm of the tuber is like the bark of a tree. It protects from moisture loss and invasion by pests. The periderm must provide protection while the tuber is rapidly enlarging. To accommodate this growth the periderm is not tightly bound to the underlying tissues so it is very easy to “slip” the skin off an immature tuber. When the tuber stops growing “skin set” process. The cell walls harden and a heavy suberized layer develops. The periderm becomes tightly bound to the underlying tissues and is then very resistant to mechanical damage. Factors affecting skin set include variety, soil type, cultural practices, environment (cold, wet soils slow set), vine maturity, time between vine kill to harvest. Smooth-skinned varieties do not set skin as rapidly as rough skinned varieties. Tubers need to stop growing for the skin to set so excess or late applications of nitrogen should be avoided. Vines should be dead for at least 10 – 21 days prior to harvest. Note that the longer potatoes sit in the soil the greater the risk of Rhizoctonia black scurf and silver scurf, however.
CROPS Tidbits & Insights continued
Volume 9, Issue 20 Veg Edge Weekly
Page 5 August 14, 2013
Average corn earworm catch
Per Day Per Five Days
Per Week
Days Between Sprays
<0.2 <1.0 <1.4 No Spray (for CEW)
0.2-0.5 1.0-2.5 1.4-3.5 6 days
0.5-1.0 2.5-5.0 3.5-7.0 5 days
1-13 5-65 7-91 4 days
over 13 over 65 over 91 3 days
Add one day to the recommended spray interval if daily maximum temperatures are less than 80° F for the previous 2-3 days.
Marion Zeufle and Abby Seaman, NYS IPM Program
WNY Pheromone Trap Network Report, 8/13/13
European corn borer (ECB) trap catches are in the single digits at all locations this week. Corn earworm (CEW) were caught at 9 locations this week with some locations needing a 5 or 6 day spray schedule (see chart below). Three sites reported fall armyworm (FAW), one site as high as 10 moths.
Western bean cutworm (WBC) was caught at 13 sites this week. The high count was once again in Plessis with 46 moths. The counts for the week are lower than last week, possibly because moth flight has peaked. The degree day accumulation (May 1st, base 50°F) for sweet corn trap network sites rang-es from 1418-1804 with an average of 1608. Most areas are above 75% WBC moth emergence which occurs at 1536 base 50 degree days (for local popula-tion). I have included a column of cumulative WBC counts to date for each site. Michigan State University recommends scouting for WBC egg masses when cumulative trap catch numbers reach 100 moth/trap for field corn. Whether this guideline also pertains to sweet corn is not known. Therefore it is recommended that all fields that are in the whorl or early tassel stage should be scouted for egg masses with a 4% threshold for processing sweet corn and a 1% threshold for fresh market sweet corn. WBC egg masses have been reported in two counties, Lewis and Genesee, with one of these sites still well below the recommended MSU guidelines for scouting in field corn. This location has a cumulative trap count of 43 WBC moths.
ECB - European corn borer CEW - corn earworm
FAW - fall armyworm WBC - western bean cutworm
R. Hadad, CVP: WNY is in the minor risk for damage from the WBC for this week but information published by insectforecast.com has noted that catches have just started in eastern parts of Ohio and Michigan with a definite pro-gression moving east.
Location ECB-E ECB-Z CEW FAW WBC Total WBC to
date
Baldwinsville (Onondaga) 1 1 1 0 3 33
Batavia (Genesee) 5 3 1 0 5 27
Bellona (Yates) NA NA NA NA NA 104
Eden (Erie) 0 0 0 0 0 15
Farmington (Ontario) 5 1 0 0 0 5
Hamlin (Monroe) 0 2 3 0 6 22
LeRoy (Genesee) 0 3 4 0 24 43
Lockport (Niagara) 0 0 0 0 0 3
Penn Yan (Yates) 0 0 3 3 6 43
Spencerport (Monroe) 0 0 0 0 0 10
Waterport (Orleans) 0 0 0 0 3 23
Williamson (Wayne) 0 3 1 0 13 63
WNY Pheromone Trap Catches: August 13, 2013
NA - not available
Risk for Damage from Western Bean Cutworm Red = High risk, Yellow = medium risk, green is minor risk (From: http://www.insectforecast.com/forecast/western-bean-cutworm-288/)
Volume 9, Issue 20 Veg Edge Weekly
Page 6
August 14, 2013
1 Weather stations. For more sites: http://newa.cornell.edu/ 2 Passed Week Simcast Blight Units (BUs) 3 Predicted Simcast Blight Units (BUs)
C. MacNeil, CVP: Late blight (LB) has been confirmed in fields and gardens in NYS, on potatoes and tomatoes, in Allegany, Erie, Genesee, Madison, Niagara, Onondaga, Schuyler, Steuben, St. Lawrence, Suffolk, Sullivan, Tompkins, Wayne, Westchester and Wyoming counties. So far all samples iden-tified in NYS, and most in surrounding states, have been US-23, sensitive to mefenoxam (Ridomil and OLF), and against which it is very effective. LB is likely present all over the state. For the most current LB confirmations go to usa-blight.org Take immediate action to limit spread and loss. Infection develops and spreads very quickly. LB lesions aren’t visible until several days after infection. In cloudy weather LB spores can move on winds and cause infection 30 miles away. Scout your fields carefully! If you suspect you have LB, contact Carol MacNeil at [email protected] or 585-313-8796, or John Gibbons at [email protected] or 585-394
-3977 x405, or other Cornell Vegetable Program Staff. Collect green foliage with suspect lesions in a ziplock plastic bag, then apply one of the very effective LB fungicides, or apply copper (organic growers), or rapidly kill by chemical or mechanical means any hot spots (where more than 5% of the foliage surface has LB lesions). If you need to hold for a short time do so at 40 – 50°F, out of the sun. If you’re shipping overnight to the Bill Fry Lab, Cornell, do so only Mon.-Thurs., and package in a box to prevent the sample from being crushed. Be sure a Report Form and Sample Number accompany your sample. They are available through online LB reporting at usa.blight.org If you’ve never reported online contact Carol MacNeil.
Generally a 5-6 day spray interval is needed at this time, if the high rate of chlorothalonil was used last week, based on late blight (LB) Decision Support System blight units or fungicide units (not shown) at the weather stations. Up to a 7 day interval is recommended in some dry locations. Consider local conditions and the fungicide used when determining the spray interval to aim for on your farm. The more specific LB fungicides, with some movement in the leaf, can generally be applied on a 7 day interval. If mefenoxam plus protectant (Ridomil Gold Bravo, OLF) is being used against LB strain US-23 it should be applied twice on a 14 day interval, with another fungicide used in between. The following fungicides are rated Good against LB tuber blight: Gavel, Ranman plus, Ridomil Gold Bravo (against US-23), according to Tom Zitter, Cornell, so growers should switch to them towards the end of the season. Revus Top is rated Fair, while Previcur Flex plus provides Suppression of tuber blight.
Location1 Blight Units2
8/07-8/13
Location1 Blight Units2
8/07-8/13
Blight Units3
8/14-8/16
Blight Units3
8/14-8/16
Albion 25 Medina 25 12 17
Appleton 11 Penn Yan 12 5 9
Baldwinsville NA Ransomville NA NA NA
Buffalo 6 Rochester 17 11 11
Ceres NA NA Romulus 32 10
Elba 37 Silver Creek 25 9 6
Farmington 35 Sodus 23 9 12
Geneva (Bejo) 32 Versailles NA 12 NA
Kendall 27 Williamson NA 12 NA
Lodi 17 Wolcott 30 10 10
Late Blight Risk Chart, 8/13/13
Stink Bug: A Pest of Tomatoes and More
J. Reid, CVP: Stink bugs have been found in higher number on tomatoes in New York this week. There are numerous species of stink bugs, some native such as the Green Stink Bug. But the Brown Marmorated Stink Bug is an invasive pest with growing Empire State presence over the last several years. This pest can feed on a number of fruit, vegetables and agro-nomic crops. Feeding damage includes a ‘cloudy’ area under the skin of the fruit, along with puncture wounds. Stink bugs have ‘piercing/sucking’ mouth parts which create these wounds. They also secrete saliva to aid in the degradation of cell walls in the fruit.
Brown Marmorated presents a more significant threat than the native species as they are present as adults much earlier
in the season. This pest is being studied, particularly in orchards, with an attempt to develop action thresholds. How many are too many in tomatoes? From Cornell Recom-mends: “No specific thresholds are available, but if the pest is found on tomato in the field, consider treat-ment to reduce feeding injury.” With what to treat?
Materials rated by the Cornell Hudson Valley Lab indicate highest efficacy with bifenthrin (Brigade or similar, 1 day PHI)and methomyl (Lannate, 1 day PHI). As field harvest of toma-toes is well underway we list here materials with the short-est PHI possible combined with the highest efficacy ratings. Very little information is available on organic materials; how-ever sulfur may act as a repellent. Planting distant from hedgerows, or woodlots, which act as overwintering sites may reduce infestations.
Late Blight Risk
Stink bug damage to tomato and pepper. Photos: Judson Reid, CVP
Stink bug nymphs on tomato. Photo: Judson Reid, Cornell Vegetable Program
Veg Edge Weekly
Page 7
Volume 9, Issue 20 August 14, 2013
Reduced Ear Size Problems in Sweet Corn
Gordon Johnson, University of Delaware Cooperative Extension, Weekly Crop Update Vol. 21, Iss. 19, 8/2/13
This wet year has brought many prob-lems for sweet corn growers. The big-gest issue has been flooding and excess soil moisture. For processing corn grow-ers, this has meant reduced field yields with smaller ears or no ears in field bottoms and poorly drained areas. For fresh market growers, wet field areas are producing unmarketable, small, or poorly filled ears. We are also seeing heavy leaf disease/blight pres-sure in some varieties. To add insult to injury, as fields dry out, irrigation deci-sions have to be based on water needs in better drained field areas, often keeping bottoms wet, further stressing corn in these areas. We have also seen unusual problems in sweet corn this year such as fungus developing on silks in storage or shipping, split kernels, and small diameter “skinny” corn.
Reduced Ear Size Ear size in corn is a function of the num-ber of rows and the number of seeds per row. The number of kernel rows that a corn plant produces in the upper most ear (the main harvest ear) is set be-tween the 5-8 leaf stages in corn (V5-V8). This is strongly determined by ge-netics. The number of potential seeds per row is determined by the 12-15 leaf stages (V12-V15) and is very much influ-enced by the environment and plant stress. Stresses during ear initiation and early formation will reduce ear diameter and ear length. In particular, inadequate nitrogen during this period (V6-V15) has been shown to reduce ear diameter and ear length. Poorly drained areas in fields will lose significant amounts of nitrogen due to denitrification. Excess water will also limit root function or cause root death if prolonged thus limiting nutrient uptake. Both these factors have resulted in reduced ear size in sweet corn in 2013. It should be noted that final ear size and seed number will be deter-mined after pollination and seed set.
Skinny Ears in 2013 Small diameter ears can occur where there is reduced row number. Because row number is largely genetically deter-
mined, only severe stress at the 5-8 leaf stage will cause a reduction in rows. This occurs with loss of leaf area such as hail injury, defoliation by wildlife or pests, herbicide damage, or other major injuries where photosynthesis is re-duced. In contrast, this year we are seeing smaller diameter “skinny” ears where row numbers have not been reduced (see pictures below). This is most pronounced in field areas that were wet during early ear development and where nitrogen was limited during that period (due to denitrification losses and delays in sidedressing because of wet field conditions). This caused smaller cobs to develop in some varieties while pollination and seed set was minimally affected resulting in small diameter ears of similar length to unaffected ears.
Looking closely at the smaller diameter ears, we see that kernel depth is similar; however, the attachment between the seed and the vascular system in the cob core is shorter and that the accessory tissues (the cob “chaff”) at the seed base are reduced or compressed. This smaller cob has caused seeds to be com-pressed together and slightly deformed. These small diameter ears, while hav-ing similar seed counts, are less attractive to consumers resulting in poorer sales. For wholesalers, small diameter corn will pack more per crate or bin but may not be accepted by buyers.
Small diameter ear (left) and normal ear (right) from variety trials at the Univ of Delaware Georgetown research farm. Note that both ears have 16 rows and that kernel depth is similar.
Small diameter ears on the left compared to larger diameter ears on the right. Tip fill is slightly reduced but length is similar.
“Skinny” ear appearance in husk (left) versus normal ears (right). Note that ear length is similar.
August 14, 2013 Volume 9, Issue 20
Dates…visit our website for a complete list of upcoming events AUGUST 20 - ROLLING HILLS DISCUSSION GROUP (UPPER FINGER LAKES) 5:30 - 7:00 PM, potluck to follow. Denis Lepel’s Farm, 1089 County Road 28, Shortsville. Have a muck pocket and not quite sure how to best to use it? Come learn about drainage, fertility management, tillage, and more! Carol MacNeil will be on hand to present and answer questions.
AUGUST 21 - REDUCED TILLAGE, COVER CROPS & SOIL HEALTH FARM MEETING 4:00 - 9:00 PM, Cuddeback Farms, 4730 State Rt 38A, Skaneateles 13151. Free beef/pork BBQ. A soil health demo by David Lamm, NRCS. David Brandt, OH, will share his 30 years of experience with no-till and cover crops. Zone till, cover crops, con-servation, transitioning from conventional will be presented by a panel consisting of Donn Branton, LeRoy; Klaas Martens, Penn Yan; Steve Nemec, Moravia; and Steve Cuddeback, Skaneateles. Machinery demos: 6-row no-till corn planter w/ liquid injection; 6-row Unverferth zone builder w/ liquid injection; no-till soybean drill w/ liquid injection; no-till grain drill. Pre-register, directions at: http://events.constantcontact.com/register/event?llr=7ex5qzeab&oeidk=a07e7qs6bub8458e853. For more info: Paul Salon at: [email protected] or 607-562-8404; or, Jason Cuddeback at: [email protected] or 315-252-4171. Sponsored by the Empire Chapter of the Soil & Water Conservation Society and New York Farm Bureau
AUGUST 21 - WEDNESDAY WALK & TALK DISCUSSION GROUP (ALLEGANY & CATTARAUGUS COUNTIES) Special evening meeting! 5:30 - 7:00 PM at J. Faulkner Farm, Rt 417, Portville. Crop walk - focusing on pest and disease man-agement and rotation planning. A potluck will follow. Open to all growers, this free meeting is focused on answering produc-er questions, education on topics identified by growers, and providing networking opportunities. Contact Elizabeth Buck at 607-425-3494 for more details.
AUGUST 27 - FRESH MARKET POTATO VARIETIES, PINK ROT, AND WATER MANAGEMENT MEETING 5:30 - 8:30 PM, Williams Farms, Marion. Pre-register for dinner - Carol MacNeil at 585-313-8796 or [email protected]. $5 for current CVP enrollees (1/enrollment); $10 for non-enrollees. 1.25 DEC credits (bring your card); CCA credits. If you are interested in sponsoring this event, click here or contact Angela Parr at 585-394-3977 x426.
AUGUST 27-28 - BEJO SEEDS OPEN HOUSE AND DEMONSTRATION TRIALS 2013 10:00 AM - 6:00 PM, 4188 Pre Emption Rd, Geneva 14456. View a wide variety of quality vegetable crops at Bejo’s Research & Demonstration Farm. (More info in July 3rd issue of Veg Edge Weekly, pg 7.) To RSVP, call 315-789-4155.
SEPTEMBER 26 - NYS DRY BEAN FIELD MEETING 5:00 - 8:00 PM, Dave Woodward’s Farm, 1530 Harris Road, Penfield 14526. Tour the Cornell dry bean variety trial and near-by strip trials. Cornell professors will share research-based ideas on pest issues and management including weed control and Western bean cutworm updates. Root rot resistance will also be discussed. DEC pesticide recertification and CCA credits will be available. $5 for current Cornell Vegetable Program enrollees; $10 for all others. Pre-register for supper by contacting Carol MacNeil at 585-313-8796 or [email protected]. For more info, visit http://cvp.cce.cornell.edu/event.php?id=111 If you are interested in learning more about sponsoring this event, click here or contact Angela Parr at 585-394-3977 x426.
NOVEMBER 7 - TOMATO SCHOOL SAVE THE DATE! Jordan Hall, NYSAES, Geneva 14456. A thorough school for tomato growers of all experience levels and farm management systems, this program will begin with the basics and move through advanced topics. Speakers from across NYS and Pennsylvania will discuss pest and disease management, hot water treatment of seeds, post-harvest han-dling, precision nutrition management, and more. Growers will share their tips and experience in raising transplants and field production. DEC credits will be available. Pre-registration will be required as space will be limited. More information on this event will be available later this summer.
NOVEMBER 8 - SQUASH SCHOOL SAVE THE DATE! CCE Monroe County, 249 Highland Ave, Rochester 14620. This school will cover pest, disease, and weed management, fertility management, post-harvest handling, and more. For squash growers of all sizes. Summer squash will be discussed, with a heavier focus on winter squash production. DEC credits will be available. Pre-registration will be re-quired as space will be limited. More information on this event will be available later this summer.
Veg Edge Weekly
Page 8
Volume 9, Issue 20 Veg Edge Weekly
Page 9
* Airport stations ** Data from other station/airport sites is at: http://newa.cornell.edu/ Weather Data, Daily Summary and Degree Days.
August 14, 2013
Weather Charts J. Gibbons, CVP:
Thank you to our sponsors:
Crop Production Services Fancher, NY (585) 589-6330 www.cpsagu.com
Pest and disease problems? Our breeders are working to develop resistant varieties! www.bejoseeds.com
Our Vision... “To be the first choice for growers in all of our marketplaces.” www.StokeSeeds.com
Blake Myers, 585-303-3252 [email protected] www.Siegers.com
Call 800-544-7938 for sales or visit www.harrisseeds.com A Grower Friendly Company
Growmark FS - Filling Your Crop Needs Visit home.growmarkfs.com to find representatives in your area.
Providing growers environmentally responsible, safe & cost-effective growing solutions. Visit www.bioworksinc.com.
PEOPLE...PRODUCTS...KNOWLEDGE… Albion, NY...(585) 589-4195 Geneva, NY...(315) 789-4450
Fungicides & Insecticides/Nematicides Western & Central NY, 585.447.7305 Eastern NY & NE, 207.890.1645
Agryl & Novagryl Row Covers, ProtekNet Insect Netting, BioTelo Biodegradable & Compostable Mulch Film. Visit www.DuboisAg.com
Rainfall (inch) Temp (°F)
Location Week Month August
Max Min
Albion 0.34 1.95 83 51
Appleton, South 0.33 1.00 82 48
Baldwinsville 0.17 0.82 85 52
Buffalo* 0.91 1.81 82 56
Ceres 0.63 0.68 81 48
Elba 2.03 3.30 80 48
Farmington 1.66 1.87 86 49
Gainesville NA NA NA NA
Geneva 1.09 1.38 81 54
Kendall 0.25 1.71 81 52
Lodi 1.70 2.11 86 53
Penn Yan* 0.98 1.32 81 52
Ransomville 0.73 1.71 82 49
Rochester* 1.04 1.68 83 53
Romulus NA NA 81 54
Silver Creek 0.45 0.51 83 56
Sodus 0.90 1.61 86 47
Versailles 1.33 1.44 81 55
Williamson 0.39 1.10 79 53
Wolcott 0.25 0.81 81 50
Weekly Weather Summary: 8/06 - 8/12
Accumulated Growing Degree Days (AGDD) Base 50°F: Jan. 1 — August 12, 2013
Location 2013 2012 2011
Albion 1757 2045 1808
Appleton, North 1567 1884 1500
Baldwinsville 1793 2141 2016
Buffalo 1814 2243 1922
Ceres 1491 1761 1731
Elba 1564 1892 1732
Farmington 1651 1963 1775
Gainesville NA 1901 1793
Geneva 1737 2113 1949
Kendall 1848 NA NA
Lodi 1806 2167 1899
Penn Yan 1775 2151 1993
Ransomville NA 2037 1810
Rochester 1873 2202 1914
Romulus 1810 NA NA
Silver Creek 1769 2054 NA
Sodus 1623 1906 1714
Versailles 1752 2016 NA
Williamson 1723 2109 1812
Wolcott 1679 NA NA
Serving Allegany, Cattaraugus,
Erie, Genesee, Monroe, Niagara,
Ontario, Orleans, Seneca,
Wayne and Yates Counties
Veg Edge Weekly is a seasonal weekly publication of the Cornell Vegetable Program providing information about crop development, pest activity and management, pesticide updates, local weather conditions, meetings and resources.
Veg Edge is published 28 times annually, monthly from October-May and weekly from May-September. If you have any questions about this publication, contact Julie Kikkert at 585-394-3977 x404 or [email protected]. Visit the Cornell Vegetable Program website at http://cvp.cce.cornell.edu/ for information on our research, upcoming events and enrolling in our program.
Cornell Cooperative Extension provides equal program and employment opportunities.
Robert Hadad 585-739-4065 Cell [email protected]
Christy Hoepting 585-721-6953 Cell [email protected]
Julie Kikkert 585-313-8160 Cell [email protected]
Carol MacNeil 585-313-8796 Cell [email protected]
Judson Reid 585-313-8912 Cell [email protected]
Cornell Vegetable Program Extension Specialists
Elizabeth Buck, 607-425-3494 Cell
John Gibbons, 716-474-5238 Cell
CVP Assistants
This publication contains pesticide recommendations. Changes in pesticide regulations occur constantly and human errors are possible. Some materials may no longer be available and some uses may no longer be legal. All pesticides distributed, sold or applied in New York State must be registered with the New York State Department of Environmental Conservation (DEC). Questions concerning the legality and/or registration status for pesticide usage in New York State should be directed to the appropriate
Cornell Cooperative Extension specialist or your regional DEC office.
Cornell Cooperative Extension and its employees assume no liability for the effectiveness or results of any chemicals for pesticide usage. No endorsement of products or companies is made or implied. READ THE LABEL BEFORE APPLYING ANY PESTICIDE.
Yates County Cornell Cooperative Extension 417 Liberty Street Penn Yan, NY 14527
Cooperative Extension Cornell Vegetable Program
Cornell University
