Wisconsin Fresh Fruit and Vegetable Newsletter
November 20, 2007

Contents:
Preparation for Winter
Apple Replant
Winter Meetings
Leafy green USDA comments
European Corn Borer
Corn Rootworm
Corn Earworm
UW Contacts

Preparation for Winter

             As I write this article winter is just around the corner.  While today is warm for late November, the forecast is for much colder weather to prevail across the state by next week.  Here are some reminders of things that need to be done around the farm before really cold temperatures arrive.

1. Strawberry growers should not be too anxious to apply mulch.  You want a little bit of frost in the soil before mulch is applied.  Having a little frost in the soil keeps equipment from sinking into wet soils and it ensures that the strawberry plants are fully dormant.  Applying mulch too early can lead to delayed dormancy, an increased risk of winter injury, and reduced yields in 2008.  Thanksgiving weekend is the typical time to apply mulch in southern Wisconsin, but we are not to the point yet when mulch should be applied to strawberries.

2. Mow orchards to remove rodent habitat.  Mowing can also have the added benefit of chopping or crushing dropped fruit so it will rot sooner and not become rodent rations.  This operation is critical to protect trees from rodent injury during the winter.

3. Don’t be too anxious to get started pruning.  My preference is to wait until after January first.  If you must begin pruning begin with your most hardy trees first.  This would probably include Cortland and McIntosh.  Delay pruning grapes until mid-winter.  Fall bearing raspberries can be cut to the ground once we get a little bit of frost in the soil.

4. Strawberry growers who used Spartan herbicide should report their use to Dr. Jed Colquhoun at UW-Madison.  One of the requirements of a Section 18 exemption is that use must be reported each year. 

5. Once the packing and sales seasons are over take another day to clean and organize the packing and sales areas.  Wipe off displays.  Sweep and mop or hose off floors.  Clean the packing line.  Sweep out the storage room.  Store bins and boxes in an orderly manner.  Repair damaged boxes or bins or discard them (not in a heap outside the shed).  Clean around your farm to show the pride that you take in owning your farm. 

6. Ensure that pesticides are stored properly for the winter.  See the article in the October 1 FreshNews Newsletter.

7. Make plans now to attend the NAFDMA conference at the Kalahari in Wisconsin Dells.  We especially hope you will attend the workshops, but the marketing information that is available at the conference will be invaluable in helping you develop ideas to market your products better.  This is an opportunity to get new and fresh ideas from people who are successful marketers from across the country.  Don’t pass it up for the cost.  Attending the workshops and the conference is a legitimate business expense.  Registration materials will be available soon.  DON’T MISS THIS OPPORTUNITY!

 Teryl Roper, UW-Madison Extension Horticulturist

Apple Replant

 During the summer apple field day at the Peninsular Research Station we had significant discussion regarding apple replant.  The opinion of the research community is that the longer you can wait between orchards the better.  Time is on your side.  Time allows the old roots to decompose and as they decompose the microbes that live on them also decline in number.  Soil borne pathogen populations also decline when there is not host on which to live.

 Our recommendation has been to remove the trees then rip the site to pull up as many old roots as possible then to crop it to something else for at least two years before replanting to apples.  If you can wait longer, three to five years, that is even better.  As you replant, avoid planting into the old tree rows.  If you are tightening up your spacing (and I hope you will) you won’t be able to avoid all old rows.

 New information suggests that not all old orchards are equal at causing replant problems.  Orchards planted to the Malling stocks (M.9, M, 26, M.7) are associated with greater replant problems than those related to other stocks such as seedling or the Budagovsky rootstocks (B.9).  However, since most orchards now in production are planted on Malling stocks this is a fine detail that may have few practical applications.  However, this is one more thing to consider in rootstock choice and replanting procedure.

 Teryl Roper, UW-Madison Extension Fruit Crop Specialist

Winter Meetings
Monday February 18, 2008

Apple Workshops:
Morning Workshop 

Designing Efficient and Productive Orchards

Curt R. Rom, University of Arkansas
Teryl R. Roper, University of Wisconsin-Madison 

Not all orchards are created equal.  Because orchards are long lived agricultural endeavors designing the orchard correctly from the outset will provide the greatest productivity and potential profitability. 

Afternoon Workshop

 Disease-warning systems for apples: What are they, and how can they help you?

Mark Gleason, Iowa State University
Patty McManus, University of Wisconsin-Madison 

Disease-warning systems are practical tools that can help apple growers cut back on pesticide sprays and save money.  They track information about the weather, disease organisms, and the crop to help you make disease management decisions.  To get the full benefit from disease-warning systems, you need to know their strong and weak points.  It also helps to get to know the enemies - the fungi and bacteria that threaten your apples – even better than you already do. 

In this workshop, two veteran extension plant pathologists take you on a stimulating exploration of the world of disease-warning systems.  They’ll help you to think like a pest – like the fungi and bacteria that attack your apples – and gain an up-to-date picture of the pro’s and con’s of using warning systems.   

This is a grower-oriented workshop that won’t dazzle you with bar charts and graphs, but will stick to practical approaches that leave you with some valuable new ideas about effective disease management.

Berry Workshops

Morning Workshop 

Soil Health:  Soil is more than minerals, air, and water

Dick Wolkowski, University of Wisconsin-Madison
Ruth Genger, University of Wisconsin-Madison

Soil is not just a matrix that holds plants upright to which all substances that support crop growth must be added.  Soils have physical properties such as their composition of sand, silt, and clay plus the amount of air and water they will hold.  These physical properties largely determine the amount of nutrients a soil can hold and make available for crop growth.  When soils become compacted these physical attributes are altered. 

Soils also have a biological component.  Fungi, bacteria, and other microbes make their home in the soil.  Some of these microbes play important roles in soil function.  Some management practices alter how many microbes are found in soil and how well they are able to function.

This workshop will provide the basis for understanding how soil works and will focus on practical steps you can take to ensure that your soil is as healthy as possible.

Afternoon Workshop

Integrated Pest Management for Berry Growers

Mike Ellis, Ohio State University
Dan Mahr, University of Wisconsin-Madison
Jed Colquhoun, University of Wisconsin-Madison
 

Vegetable Workshops:
The vegetable program at this years Fresh Fruit and Vegetable Growers’ Conference on Monday, February 18^th will consist of the following topics with the specific agenda to be posted in the Fresh Market Vegetable Grower Newsletter:

Tomato Production
Tomato Production and Marketing – Wurth Brothers Farm, Paducah, KY
Disease Management in Tomatoes – Karen Delahaut, Department of Horticulture, University of Wisconsin
Insect Management in Tomatoes – Russ Groves, Department of Entomology, University of Wisconsin
Cultural Management in Tomatoes – A.J. Bussan, Department of Horticulture, University of Wisconsin

Vine Crop Production
Weed Management in Vine Crops – Jed Colquhoun, Department of Horticulture, University of Wisconsin
Disease Management in Vine Crops – Karen Delahaut, Department of Horticulture, University of Wisconsin
Insect Management in Vine Crops – Russ Groves, Department of Entomology, University of Wisconsin
Irrigation Scheduling and Cultural Management in Vine Crops – A.J. Bussan, Department of Horticulture, University of Wisconsin
New Melon, Cucumber, Squash, and Pumpkin Cultivars – To be announced

USDA Seeks Comments on Proposed National
Leafy Greens Handling Regulations

The US Department of Agriculture is seeking comments on a proposed federal marketing program to regulate the handling of leafy green vegetables throughout the country. The public – growers, handlers, buyers, sellers, and consumers of leafy greens – is invited to submit comments and information that would help USDA evaluate the need and support for a nationwide program.

 USDA is considering implementation of a marketing program in response to public and industry concern about reducing the risk of pathogenic contamination during the production and handling of leafy greens. Options being considered: a marketing agreement that requires handlers to comply with the agreement’s regulations after voluntarily entering the program; and a marketing order that would be implemented following a grower referendum, requiring mandatory compliance for all handlers.

 USDA believes that a marketing agreement is most likely to meet the needs of the national industry. In the program under consideration, packers, processors, shippers, and marketers, as signatories under a marketing agreement of leafy greens, could be required to certify – and for USDA to verify – that their products are produced and handled according to best practices specified under the agreement.

 If the response to this request is favorable, USDA will proceed with the development of the marketing program in cooperation with the industry and a notice of public hearing will be published in the Federal Register. Public comment and rulemaking will precede implementation of the proposed marketing agreement.

 Comments must be received by December 3, 2007. Copies may be obtained from Laurel May or Kathy Finn, 1400 Independence Avenue SW, Stop 0237, Washington, DC 20250-0237; by calling 202-720-2491; or faxing 202-720-8938.

EUROPEAN CORN BORER

The fall abundance survey of 230 fields registered a minor increase in population densities compared to the fall of 2006. The number of European corn borers entering the winter of 2007 increased to 0.31 per plant from 0.29 per plant in 2006. The state average is equal to the 10-year average of 0.31 per plant and below the 50-year average of 0.48 per plant. Increases were noted in the southwest (0.20 to 0.28 per plant), west central (0.42 to 0.52 per plant), east central (0.11 to 0.21 per plant), and north central (0.16 to 0.35 per plant) districts. Decreases were documented in the remaining five districts.

Approximately 53% of the fields of grain corn had no detectable larval population; some of these unquestionably were Bt hybrids. Roughly 23% of the fields had populations exceeding 0.50 borer per plant and 8% had populations above the economic threshold of 1.0 borer per plant. Three counties -- Eau Claire (1.7 per plant), Pierce (1.14 per plant), and Waupaca (1.9 per plant) -- had average densities greater than 1.0 borer per plant. The state mean percentage of corn plants infested with second generation larvae was 28%.

Many instances of ear shanks being infested with corn borer were noted during the fall survey. This feeding behavior, which resulted in hollow, weakened shanks and eventual ear drop, may have been due to borers finding the shanks more desirable than the saturated, rot-infected stalks. Stalk rot was widely prevalent this fall because of stress from drought early in summer followed by late season rains.

Results of the 2007 survey suggest another light first flight of moths should be expected next spring. Planting Bt hybrids for European corn borer management in 2008 may be unwarranted in many areas (except those represented by red or yellow circles on the map below), considering that borer pressure is expected to be very low. From  DATCP Cooperative Pest Survey Bulletin

CORN ROOTWORM

Analysis of the annual corn rootworm beetle survey revealed a state average population of 1.0 beetle per plant. This represents a decrease from 1.4 per plant in 2006 and 1.6 per plant in 2005. Averages by agricultural reporting district were as follows: northwest 0.4 per plant; north central 0.7 per plant; northeast 0.5 per plant; west central 0.4 per plant; central 0.8 per plant; east central 1.4 per plant; southwest 0.4 per plant; south central 2.2 per plant; southeast 1.0 per plant. The western species was dominant on a statewide basis, while populations of the northern species were higher in the cooler and more northern counties, including Barron, Chippewa, Door, Dunn, Clark, Green Lake, Juneau, Lincoln, Marathon, Marinette, Oconto, Pepin, Polk, Portage, Rusk, Shawano, Taylor, Vernon, Waupaca, Winnebago, and Wood. About 39% of the 222 corn fields surveyed had economic populations of 0.75 or more beetle per plant. The largest increase from 1.7 to 2.2 beetles per plant was documented in the south central district, while the largest decreases from 2006 to 2007 were noted in the southwest (2.2 to 0.4 per plant), northeast (1.8 to 0.5 per plant), and east central districts (2.2 to 1.4 per plant). An average of 0.75 or more beetles per plant indicates the potential for feeding injury by corn rootworm larvae in multi-year corn.

The use of transgenic Bt corn rootworm hybrids was also measured this season. The percentage of survey sites that were Bt corn rootworm fields nearly doubled from 14% in 2006 to 27% in 2007. For the second year, Monsanto's YieldGard was the more prevalent of the two technologies. A total of 23% of the fields tested positive for the YieldGard Bt-Cry3Bb1 protein, while just 4% tested positive for the Herculex Bt-Cry34/35Ab1 protein. More Bt-rootworm corn was planted in the southwest and south central districts in 2006 and 2007 relative to the other districts. The maps below summarize the results of the annual corn rootworm beetle survey. From  DATCP Cooperative Pest Survey Bulletin

Corn Earworm

Migratory adults first appeared at the Lancaster monitoring site in early June and the treatment threshold of five moths per night was quickly surpassed between June 7 and 17. This early flight was exceptional; moth captures were very low throughout June and July at the other 13 trap sites. The first threshold-level captures for the main flight, averaging five moths per night or greater, were reported as follows: Cottage Grove (July 31), Oregon/Stoughton (July 31), N Sun Prairie (July 31), Reedsburg (August 1), Marshfield (August 6), NE Sun Prairie (August 7), Chippewa Falls (August 8), Lancaster (August 9), Coon Valley (August 10), and Manitowoc (August 28). Numbers at most locations continued to be above-threshold for the remainder of the season. The peak flight period, when counts averaged 0.2 to 206 moths per night, occurred between August 12 and September 9. Economic captures of moths were documented at ten of 14 trap locations in 2007. -- Clarissa Hammond DATCP Cooperative Pest Survey Bulletin

UW Fresh Fruit and Vegetable Contacts