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Volume 15, Issue 2 April 2012
Central Wisconsin Agricultural Extension Report
An EEO/Affirmative Action employer, University of Wisconsin-Extension provides equal opportunities in
employment and programming, including Title IX and ADA requirements
Food Safety and Good
Agricultural Practices Begin
on the Farm 2
Identifying Pasture Grasses 3
On-Farm Research
Opportunity: Using
Perennial Cover Crops in
Commercial Vegetable
Production Systems
3
Selling $1,000 Calves 4
June Dairy Breakfasts 5
Attention to Replacement
Heifers Pays 6
Grow Wisconsin Dairy
30 x 20 Initiative 7
Considering Late Blight
Management in 2012 8
Inside this issue:
Soil pH: Lessons Learned or Lessons Forgotten? By: Donald Genrich, Adams County
“So without question, the most important single chemical characteristic of a soil as regards its suitability for plant growth is its reaction or pH status.” Quoting Emil Truog, distinguished Wisconsin soil scientist (born March 6, 1884 on a farm at Independence, Wisconsin) in the book Mineral Nutrition of Plants that he wrote/edited in 1951. Sixty years ago Emil Truog understood this basic truth about soil. I‟m not sure we still have the same appreciation for this elementary truth today. Our focus today seems to be on supplying nutrients or other additives that we hope will enhance plant growth and yield. But we have a long history of agricultural research that shows that crop health, crop growth, crop yield and the nutritional value of the crop produced are all optimized by appropriate soil pH. A given soil‟s physical, chemical and biological properties and processes are all affected by its pH. For example, the availability of phosphorus in soil is directly related to soil pH because P exists in soil in different chemical forms that have different availabilities to plants at different pH values. Phosphorus has greatest availability between pH 6.4 and 6.8. As soil pH becomes more acidic, iron and aluminum phosphates form and P becomes less available. As pH becomes more alkaline, calcium phosphates form and P again becomes less available. Another example would be that the availability of the micronutrients manganese, zinc, boron, iron and copper decreases as soil pH increases. Deficiencies of manganese in soybeans and zinc in corn are much more common in soils with a high pH (7.0 or more). The organisms that live in the soil, that enhance the growth of plants or hinder the growth of plants, flourish or do not flourish depending upon whether the soil pH is optimum for them. For example, the Rhizobium bacteria that fixes nitrogen for alfalfa is most active at pH 6.8. Biological conversion of the nutrients held in soil in organic form to inorganic forms available to plants is optimized at pH 6.5. The organisms that cause the disease Brown Stem Rot in soybeans are more active as the soil pH decreases below 6.0. But, conversely, the incidence of soybean cyst nematode increases as soil pH increases. Snap bean yield increases and incidence of root rot in snap bean decreases as soil pH increases. Scab in potatoes will decrease as soil pH decreases. It is difficult to determine an optimum soil pH because many times there are conflicting needs of our rotational crops. For the potato crop we lower the pH to help control scab and at the same time make phosphorus less available. Yet, the snap bean crop raised in rotation with potatoes really needs a higher pH to optimize yield. A very narrow range in soil pH from 6.3 to 6.5 is optimum for soybeans, because in this range nutrient availability and biological nitrogen fixation are maximized and disease pressure from Brown Stem Rot and soybean cyst nematode is minimized. We need to think about and realize that we can do a lot, but not everything, to enhance soil nutrient availability, manage disease pressure and maximize biological activity by optimizing soil pH. As Emil Truog stated so many years ago, it is the single most important thing that we should do to enhance our soils.
PAGE 2 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT VOLUME 15, ISSUE 2
Food Safety and Good Agricultural Practices Begins on the Farm By: Nav Ghimire, Green Lake County
An agricultural farm involves a chain of activities right from land preparation, planting, harvesting farm products, value added processing, and its final delivery to targeted consumers. Therefore, it is important that farm should make sure the food delivered to consumer is safe for consumption. The activities such as employee training, proper labeling, design of the farm or ranch operation, and its physical layout can affect food-safety risks.
Food safety is a growing issue in the United States and around the world. According to the Center for Diseases Control and Prevention, each year roughly 1 in 6 Americans (or 48 million people) gets sick, 128,000 are hospitalized, and 3,000 die of foodborne diseases. In past years, salmonella outbreak in spinach and eggs in the United States and in cucumber in Europe are some of the examples of food safety risk.
The food safety on the farm can be ensured adopting Good Agricultural Practices (GAP) and Good Handling Practices (GHP). GAPs usually deal with pre-harvest practices (i.e., in the field), while GHPs cover postharvest practices, including packing and shipping. GAPs and GHPs are highly relevant for a farm that is involved in fresh market fruit and vegetable production.
Due to growing concern for food safety over the years both by consumers and by the vendors of fresh market fruits and vegetables, a particular grower or packer may require to have a formal, documented GAPs program in place. According to University of Wisconsin-Extension and Florida State University Extension, following GAPs statements and explanatory comments should be considered in any comprehensive produce food safety program. The accompanying checklist can be used as a preliminary assessment tool for individual farm operators. Water: The quality of the water used in any operation directly impacts the potential for risk of foodborne illness from the product. This consideration should include water used for irrigation, mixing pesticides and other foliar-applied products, frost protection, processing water (such as flumes, product sanitation, and cooling operations), and equipment sanitation. The operator should be aware of the source, distribution and quality of all water utilized. Manures: Properly treated manures can be safe fertilizer if the proper precautions are in place. Use treatments to reduce pathogens in manure and other organic materials. Treatments may be active (e.g., composting) or passive (e.g., aging). Be aware that locating manure treatment and storage sites close to fresh produce fields increases the risk of contamination. Consider factors such as slope and rainfall and the likelihood of runoff into fresh produce production areas. Use barriers or physical containment to secure storage and treatment sites. Worker Health and Hygiene: Infected and/or unhygienic employees who work with fresh produce can increase the risk of transmitting foodborne illness. Train employees to follow good hygiene practices. Establish a training program about health and hygiene. Include basics, such as proper hand washing techniques and the importance of using toilet facilities. Become familiar with typical signs and symptoms of infectious diseases. Offer protection to workers with cuts or lesions on parts of the body that may make contact with fresh produce. Sanitary Facilities: Poor management of human and other wastes in the field or packing house can significantly increase the risk of contaminating produce. Toilet facilities should be properly located and should be accessible. Both toilet facilities and hand washing stations should be well-supplied and all facilities should be kept clean. Field Sanitation: Fresh produce can become contaminated from contact with soil, fertilizers, water, workers, and harvesting equipment during pre-harvest and post-harvest activities. Clean harvest containers or bins prior to use. Take care not to contaminate fresh produce that is already washed, cooled or packaged. Use harvesting and packing equipment appropriately and keep it as clean as practicable. Assign responsibility for equipment to the person in charge. Packing Facilities: Maintain packing facilities in good condition to reduce the potential for microbial contamination. Remove as much dirt as practicable outside of packing facility. Clean pallets, containers, or bins
(Continued on page 3)
PAGE 3 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT VOLUME 15, ISSUE 2
Can you identify the 15 most common grasses in mid-western pastures? Do you know the most ideal use for each species? If not, you may want to get a copy of the University of Wisconsin-Extension‟s publication, “Identifying Pasture Grasses”. Grasses are the base of mid-western pastures. They can supply good yields of quality feed. This booklet contains information about seed and seedling identification for new plantings; identification of new established plants; and information about growth habits and management for each of the seeded grasses. Producers may want to consult the grass management and description sections of the book before buying seed. These sections describe the ideal uses for each species and outline the best techniques for successful establishment, management and harvest. A species information chart summarizes seeding rates and relative tolerance for drought, traffic and weed suppression. The guide can help producers identify grasses during the first seeding year, when it‟s important to know if the seeding was successful. The guide can also help producers identify grasses in established pastures to make informed decisions about pasture management, fencing and renovation. “Identifying Pasture Grasses”, publication A3637 is available for $7.00 from your County Extension Office.
Identifying Pasture Grasses By: Craig Saxe, Juneau County
before use. Discard damaged containers. Keep packing equipment, packing areas, and storage areas clean. Make sure to store empty containers in a way that protects them from contamination. Establish and maintain a pest control program. Transportation: Proper transport of fresh produce will help reduce the potential for microbial contamination. Good hygienic and sanitation practices should be used when loading, unloading, and inspecting fresh produce. Inspect transportation vehicles for cleanliness, odors, and obvious dirt and debris before loading. Avoid leaving harvested crop in the sun and maintain proper temperatures throughout the transportation process. Load produce to minimize physical damage. Traceback: The ability to identify the source of a product is an important component of food safety programs. Documentation should include the source of the product, the date of harvest, farm identification, and a record of who handled the product. The product must be traceable from the farm through the packers, distributors and transporters, and retailers.
On-Farm Research Opportunity – Using Perennial Cover Crops in Commercial Vegetable Production Systems
By: Ken Schroeder, Portage County
This is a great opportunity for irrigated vegetable growers in central Wisconsin to take part in expanding some very interesting research on the use of perennial legume cover crops in commercial vegetable cropping systems based on positive results of recent studies done at the Hancock Ag Research Station and field research by Prince Farms of Hancock. Potential Benefits of Participation:
Saving money on purchased nitrogen. Improving groundwater quality through the use of slow-release organic nitrogen from a legume versus com-
mercial fertilizers. Get first-hand experience with a new innovative, sustainable vegetable production system.
Here’s what it’s all about. We are looking to incorporate red clover use as a cover crop in vegetable rotations to supply 50 to 60 or more pounds of nitrogen per acre to sweet corn, field corn, and potato crops. For more details: call or email Ken Schroeder, Portage County Agriculture Agent 715-346-1316, [email protected]
PAGE 4 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT VOLUME 15, ISSUE 2
Selling $1,000 Calves By: Keith VanderVelde, Marquette County
As we look toward fall with low cow numbers and high calf prices the cow-calf producer has a real opportunity to generate a profit in 2012 and 2013. In February and March of 2012 we have already selling $2.00 per lb. prices for 500-550 lb. steer calves in many areas of the county. Recently 750-800 lb. steers are selling in the $170-$180 per cwt. Prices for 500 lb. steer calves are project to be in the $1.80-2.10 range this fall and could exceed these levels in the February-March period in 2013. So what can a producer do to generate the most income from the upcoming calf crop. Here is a list of items that will help obtain market premiums: Increase weaning weights:
Good Genetics-by bulls with above average EPD‟s
Have good milking cows
Provide Good Pastures-avoid late summer slumps
Market at times of high calf prices
Avoid selling at the seasonal low periods of Nov-Dec. Genetics are Changed with Bull Power
Bulls make up 50% of the genetic makeup in a herd
In three generations the genetic material from 3 bulls are 87.5% of the genetic makeup of the herd.
Take advantage of Crossbreeding-heterosis increases weaning weights, pregnancy rate, milk production and longevity.
Understand the differences between breeds and know how to compare genetic values between breeds using the Across Breed EPD Values.
Breed Birth Wt. Weaning Wt. Yearling Wt. Milk
Hereford 2.8 -1.5 -17.1 -18.7
Angus 0 0 0 0
Shorthorn 5.9 17.9 41.7 19.6
Simmental 4.8 25.9 24.5 15.3
Limousin 3.6 0.9 -31.3 -13.4
Charolais 8.5 40.1 48.9 4.6
Maine Anjou 4.3 -9.8 -28.5 -3.7
Gelbvieh 3.8 3.9 -10.4 10.2
Tarentaise 1.8 34.8 22.5 23.0
Salers 2.0 -0.3 -10.5 0.5
BIF 2011 Across Breed Adjustment Values
(Continued on page 5)
PAGE 5 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT VOLUME 15, ISSUE 2
Good Milking Cows:
Breeds high in milk production are: Simmental, Gelbvieh, Tarentaise
Medium milking breeds are: Red Angus, Angus, Shorthorn
Lower milking breeds are: Hereford, Limousin, and Charolais
Make sure you match the milking ability to your feed and forage supply
Use crossbred cows to increase milk production Provide good pasture and forage:
Use Rotational Grazing
Fertilize grass pasture or use a grass/legume mix
Creep feed calves in times of drought or overstocked pastures
Stockpile forage for September-October grazing
Wean calves before cow body condition declines Time Your Marketing to Achieve Top Dollar
Avoid the October-December Price decline when most calves are sold
Sell in late summer or in February-April.
History over the past 10 years shows a $30 per cwt. difference in value between the April and November price of calves. That is $150 for a 500 lb. steer
Delay the Calving Period to April and May:
Calve on Grass- less disease problems
Reduces winter feeding costs
Market calves in Early Spring
Remember to keep breeding season to 60 days if possible Precondition Calves Prior to Selling:
Vaccinate, dehorn, Castrate (knife method preferred at most markets)
Wean 30 days before selling-use fence line weaning method locking cows in pen and letting calves remain in pasture
Offer uniform package of calves, same color, same size.
Become a BQA Certified Producer-your UW-Extension Agriculture Agent has the information to participate.
June Dairy Breakfasts
1 Marshfield Mayor’s Dairy Breakfast Central Wisconsin State Fairgrounds, Expo Building 513 E. 17th Street, Marshfield, WI 54449 9 Juneau County June Dairy Breakfast Bell’s Udder Farm N6689 Cty Rd. H, Camp Douglas, WI 54618 7:00 AM to 11:30 AM More info: http://juneau.uwex.edu 16 Portage County June Dairy Day Gordondale Farms 9845 Hwy 161, Amherst Junction, WI 54407 8-12 Noon. Donation: $6 (adults), $2 (Children 6-10 years) Children 5 and under free 17 Marshfield FFA Alumni June Dairy Breakfast Hosted by the Gilbertson Family: James and Linda Gilbertson N4941 Fairhaven Avenue, Chili, WI 54420 7 AM-12PM, $6.00 for ages 11 and up, $3.00 for pre-
school to age 10
22 Wisconsin Rapids Berry-Dairy Breakfast Lincoln High School 1801 16th Street South, Wisconsin Rapids, WI 54494 6-10:30 AM 24 Auburndale FFA Alumni Dairy Breakfast 24 Waushara County Dairy Breakfast
Sorenson Hillview Jersey Farm W3995 County Road H, Pine River, WI 54965 7:30 am to 12 noon Adult donation $6, Children donation (4-10) $3
30 Pittsville FFA Dairy Breakfast Mike and Tina Fox Horse Farm 5775 Maplewood Road Vesper, WI 54489
PAGE 6 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT VOLUME 15, ISSUE 2
Attention to Replacement Heifers Pays By: Matt Lippert, Wood County
These are interesting times, with week old Holstein bull calves selling for $250. It causes me to pause and consider the investment in raising a good replacement heifer into the herd. Bull calves are not valuable because they are cheap to feed; quite the contrary, most forages are at least $150/ton of dry matter and grains and protein sources are also high. A fact that concerns me is that on the average dairy heifers are a couple months over two years old when they calve for the first time. Let‟s say that the target weight for a well grown first calf heifer is 1300 pounds; at 26 months of age that requires an average daily gain of just 1.5 pounds per day. Physiologically we know from the performance of Holstein bull calves that twice that amount is readily obtainable. Well managed Holstein heifers can reach the desired weight and with acceptable frame size quite consistently by a year and ten months. A still rather modest average daily gain of 1.8 pounds per day is needed to freshen heifers at that age. Feed costs today often run $1.25/head/day to raise replacement heifers, adding other costs including labor, housing, manure handling and veterinary care, many have $2.00 per day or more invested in raising replacement heifers. So the extra cost of freshening these heifers as we are at four months of age older than what we could be costs us nearly $250 for every single heifer. We need to step back and consider the barriers to why we allow this extra expense to happen. Have we convinced ourselves that while other producers grow beautiful heifers that do well and stay in the herd for a long time and freshen at a year and ten months that somehow on our own farm they need a little more time to mature? Have we allowed inadequate facilities to limit the performance of our heifers? Have we allowed poor ventilation to sabotage their growth potential due to damaged respiratory systems? Have we grown them well but just can‟t seem to get them bred? Do we have acceptable feeds but we have failed to formulate them in a proper ration to obtain the desired growth? Have we fed very low quality feed that won‟t allow adequate growth? Today, even straw runs over $130/ton for dry matter but many very acceptable forages with more energy and protein can be found for only $20-30 more per ton. We need to identify the bottlenecks and eliminate this waste that most of us cannot afford. This message is an old one, one that is even more important during these times of higher value animals and more expensive feed. Freshening heifers four months earlier would reduce the amount of building needed by 15%, or utilize the same building with much more comfortable animals using less bedding and creating less manure because there are only 85% as many there as used to be. I used Holsteins as the example but the same situation is true for other breeds, in fact many of the smaller framed animals mature more quickly and are even more suited to earlier calving. In many cases feed amount or quality may not be the factor; but if it is, please pencil out how much you feel you are saving per day on the lower quality feed and compare to how much more you are spending by feeding them all of those extra days. A more recent message on heifer growth has come from the Marshfield Agriculture Research station. On many farms there is a lack of lower quality heifer feed and milking herd quality forages are fed to heifers that gain weight too quickly. Patrick Hoffman has found that limit feeding these heifers is a viable option. It requires management such as making sure that all animals have access to the feed bunk when the feed is delivered, because there will be a significant portion of the day when the manger will be empty. One advantage is that for the same amount of growth much less manure will be produced. Our experience at the Marshfield station and from what we know about feeding steers tell us that the growth potential of our dairy replacements is much greater than what I am suggesting to calve them at under two years of age. How sad in these days of expensive feed that our biggest problem is still taking too long to get our replacement herd into the milking string.
Visit the Central Wisconsin Agricultural Specialization Team on the Web
http://fyi.uwex.edu/cwas/
PAGE 7 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT VOLUME 15, ISSUE 2
Grow Wisconsin Dairy 30x20 Initiative By: Ken Williams, Waushara County
The Wisconsin Dairy Industry is the largest contributor to the state‟s economy. The dairy industry accounts for nearly 40% of all Wisconsin agriculture jobs, employing more than 146,000 people in our state. Dairy is the cornerstone of Wisconsin‟s agricultural industry. Economically it means more to Wisconsin than citrus does to Florida, potatoes to Idaho, apples to Washington or lobster to Maine. The dairy industry has a $26.5 billion impact on Wisconsin‟s economy and employs more than 146,000 people in the state. In 2011 the 11,000 licensed dairy herds in Wisconsin produced 26.1 billion pounds of milk. It is estimated that 84 percent of the milk produced is used for the production of cheese. In 2009 there was over 2.6 billion pounds of cheese produced in Wisconsin. According to Wisconsin Milk Marketing Board calculations it is estimated that Wisconsin in 2010 imported 2.6 billion pounds, or 10 to 16 percent, of the milk used to meet its cheese making demands. Reducing the amount of miles between a farm and a cheese plant reduces the cost and the environmental impact of the cheese production process. The less milk is agitated prior to the cheese making process, less transportation; the better is the cheese that is produced.
Governor Scott Walker announced a Grow Wisconsin Dairy 30x20 Initiative at the Professional Dairy Producers of Wisconsin 2012 Business Conference on March 13. The goal of the Grow Wisconsin Dairy 30x20 Initiative is to achieve an annual milk production of 30 billion pounds by 2020 to meet the growing demand of the marketplace and improve the long-term viability of Wisconsin‟s dairy industry.
The Grow Wisconsin Dairy 30x20 replaces the Dairy 2020 program that formerly operated through the Wisconsin Department of Commerce until being moved to the Department of Agriculture, Trade and Consumer Protection (DATCP) last year. Since then, DATCP Secretary Ben Brancel has led dairy discussions with industry leaders from across the state to develop the direction for the Grow Wisconsin Dairy Team and identify the needed resources. This assistance will be in the form of resources and services for dairy producers. According to the Department of Agriculture, Trade and Consumer Protection (DATCP), Grow Wisconsin Dairy Grants will be available to retain farms, facilitate operation changes, improve profitability and yield more milk. These grants will be dedicated to two specific areas. Planning and preparation teams will focus on business development and expansion, while dairy profit teams will hone in on improving management and increasing profit for existing dairies. Through a toll-free number, 855-WIDAIRY, they can access information from financial planning to tax incentives for start-up, relocating, growing, expanding, modernizing or improving Wisconsin dairies. Producers may also explore online resources at www.GrowWisconsinDairy.wi.gov, or email their information requests to [email protected].
Wisconsin dairy plants invested $1.24 billion in equipment and facilities between 2004 and 2009, according to a 2009 survey of dairy plants conducted by the United States Department of Agriculture and the Wisconsin Department of Agriculture, Trade and Consumer Protection. Nearly 60 percent of plants surveyed expected to increase their product volume between 1 and 25 percent, the survey results state. Another 15 percent of the plants surveyed expected to increase by more than 26 percent, the report states. Wisconsin‟s dairy industry is what it is today because of dedicated dairy farmers across the state. Working Wisconsin farm families and individuals own 86.8 percent of the farms in Wisconsin.
PAGE 8 VOLUME 15, ISSUE 2 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT
Late blight is a potentially destructive disease of tomatoes and potatoes caused by the fungal-like organism, Phytophthora infestans. This pathogen is referred to as a „water mold‟ since it thrives under wet conditions. Symptoms of tomato and potato late blight include leaf lesions beginning as pale green or olive green areas that quickly enlarge to become brown-black, water-soaked, and oily in appearance. Lesions on leaves can also produce pathogen sporulation which looks like white-gray fuzzy growth. Stems can also exhibit dark brown to black lesions with sporulation. On potato tubers, late blight symptoms include firm, brown, corky textured tissue. The time from first infection to lesion development and sporulation can be as fast as 7 days, depending upon the weather. Control of late blight in the field is a critical component of long term disease prevention, as infected plant parts, if unexposed to winter killing frost conditions, can carry the pathogen from one growing season to the next. With an earlier start to the potato and vegetable production season in 2012 comes an earlier start to disease risk. We had a limited number of late blight detections in tomato and potato last year, with a single report on tomato in mid-July in Waukesha County and a handful of detections on potato in late-August in northern Waushara and Adams Counties. Growers in these areas of Wisconsin should be watchful for early symptoms and signs of late blight on susceptible tomato and potatoes and on solanaceous weeds (nightshade species). Tubers infected from late blight of genotypes US-23 or US-24 in late season 2011 may result in volunteers with these strains in 2012. The disease cycle in figure 1 depicts how this disease cycle works. The national late blight tracking project is again online in 2012. Over the past week, there have been confirmed reports of potato late blight in Florida and in California (www.usablight.org).
Summary of genotype characterization: Isolates of Phytophthora infestans from tomato and potato were collected in 2009, 2010, and 2011 for characterization in Wisconsin. Each isolate was evaluated for sensitivity to the fungicide mefenoxam, compatibility type, and allozymes genotypic profile or “genotype”. A smaller group of isolates was further characterized for host range, RFLP profile, and growth optima at different temperatures on artificial media and host tissue. Results of our P. infestans characterization work further our understanding of the biology and dynamics of the pathogen population and lend to the development of improved disease management recommendations.
(Continued on page 9)
Considering Late Blight Management in 2012 By: Amanda J. Gevens, Vegetable Plant Pathologist, UW-Madison
Figure 1. Disease cycle of Phytophthora infestans, the pathogen causing late blight of tomato and potato. Illustra-tion credit to Rosemary Clark, UW-Plant Pathology.
With the recent presence of the late blight pathogen in Wisconsin, and the likelihood of disease-favorable weather conditions in 2012, it is critical that all growers of tomatoes and potatoes be on alert and prepared for late blight control. Key components of late blight control in potato are:
1) Destroy all potato cull piles (May 20 deadline by DATCP) consider recent warmer temperatures 2) Manage potato volunteers in all fields -volunteers pose great risk for late blight introduction 3) Acquire disease free seed from a reputable certified source –infected seed poses great risk for introduction 4) If there is a risk of disease associated with seed, use seed treatment or in-furrow application of effective
late blight controlling fungicides (seed treatment is best) 5) Apply only proven effective fungicides for control of late blight when disease forecast tool indicates
environmental risk and stay on a fungicide spray program (DSVs reach 18) a. For conventional systems, a current list of registered late blight-specific materials can be found in
the Commercial Vegetable Production in Wisconsin A3422 publication (further information below)
b. For organic systems, copper-containing fungicides are the only proven effective materials for preventing late blight in susceptible crops
6) Scout regularly and thoroughly for disease in all potato fields 7) Re-apply effective fungicides for disease control on a 7 day schedule (recommendation adjusts to a 5 day
schedule when late blight is in the area and weather favors disease; recommendation adjusts to a 10 day schedule when late blight is not found in area and weather is hot and very dry)
8) If late blight is identified in a field, have a mitigation plan in place for specific site. Depending on days to vine kill, environmental conditions, and extent of infection – plan may vary from complete crop destruction to early vine kill with continued maintenance fungicide sprays. Mitigation plan should limit disease spread within field and from field-to-field.
Wisconsin fungicide recommendations for late blight can be found in the University of Wisconsin Extension Publication entitled “Commercial Vegetable Production in Wisconsin,” publication number A3422 (http://learningstore.uwex.edu/assets/pdfs/A3422.PDF) and additional information is provided in weekly newsletters during the growing season (provided at the vegetable pathology website: http://www.plantpath.wisc.edu/wivegdis/). I will begin posting Blitecast disease severity values (DSVs) for Wisconsin in the upcoming weeks. Amanda J. Gevens, Vegetable Plant Pathologist, UW-Madison, Dept. of Plant Pathology, 608-890-3072 (office), Email: [email protected].
PAGE 9 CENTRAL WISCONSIN AGRICULTURAL EXTENSION REPORT VOLUME 15, ISSUE 2
*Opposite mating types were not isolated from the same fields or from the same counties. Co-inoculations of an A2 late blight isolate collected from Wisconsin in 2009 with a reference A1 isolate on tomato and potato leaves resulted in leaves with water-soaked lesions consistent with late blight symptoms. No oospores were produced on plant tissue. We are further evaluating compatibility type features of the P. infestans isolates.
Genotype Mefenoxam sen-
sitivity
Mating
type*
Temperature fa-
voring greatest
growth
Comments on host range
US-22 Sensitive A2 24°C Can infect tomato and potato; could not infect
foliage of single variety of tomatillo, egg-
plant, pepper, ground cherry; could infect
foliage of hairy, black, and bittersweet night-
shade (limited sporulation). Found in WI in
2009, 2010.
US-23 Intermediately
sensitive
A1 18°C Found on tomato in southeastern WI in 2010
and 2011. Found on potato in central WI in
2011.
US-24 Intermediately
sensitive with
great variability
among isolates
A1 20°C Found primarily on potato in Wisconsin in
2010 and 2011.
An EEO/Affirmative Action employer, University of Wisconsin-Extension provides equal opportunities in employment and programming,
including Title IX and ADA requirements.
Nav Raj Ghimire
Green Lake County Agronomy, Commercial
Horticulture & Marketing
571 County Road A
Box 3188
Green Lake, WI 54941-3188
(920) 294-4032
Keith VanderVelde
Marquette County Livestock Production &
Emerging Markets
480 Underwood Avenue
PO Box 338
Montello, WI 53949
(608) 297-9153
Matt Lippert
Wood County Dairy & Cranberry Production
Courthouse, 400 Market St.
PO Box 8095
Wisconsin Rapids, WI 54495-8095
(715) 421-8440
Ken Williams
Waushara County Farm Business Management
Courthouse, 209 S. St. Marie
PO Box 487
Wautoma, WI 54982-0487
(920) 787-0416
Donald Genrich
Adams County Agronomy & Nutrient Mgt. 569 N. Cedar, Suite 3
Adams, WI 53910
(608) 339-4237
Ken Schroeder
Portage County
Vegetable Production Ruth Gilfry Center
817 Whiting Avenue
Stevens Point, WI 54481
(715) 346-1316
Craig Saxe
Juneau County Dairy & Forage Management 211 Hickory St.
Mauston, WI 53948-1386
(608) 847-9329
How to Contact Team Members
Return Service Requested
Juneau County
211 Hickory St. Mauston WI 53948-1386
NONPROFIT ORG
U.S. Postage
PAID
Mauston, WI 53948
PERMIT NO. 106
