Address any questions or comments regarding this newsletter to the individual authors listed after each article or to its editors, Nathan Johanning, 618-939-3434, njohann@illinois.edu or Bronwyn Aly 618-695-6060, baly@illinois.edu. The Illinois Fruit and Vegetable News is available on the web at: http://ipm.illinois.edu/ifvn/. To receive or be removed from email notification of new postings of this newsletter, contact Nathan Johanning or Bronwyn Aly at the phone numbers or email addresses above.

In This Issue:

Upcoming Programs (listings for beginning and established growers)

Regional Reports (from western and southern Illinois)

Vegetable Production and Pest Management (corn flea beetle & stewart's wilt, preparing for corn earworm, 2015 Illinois farmer's market pricing summary, and pricing information & marketing resources))

Food Safety Updates (Produce Safety Rule: Agricultural Water Quality, article 3 of 7)

University of Illinois Extension educators and specialists in fruit and vegetable production and pest management

Upcoming Programs

Check the Illinois SARE calendar for a full list of programs and links for registration.
http://illinoissare.org/ and http://illinoissare.org/calendar.php
Also see the University of Illinois Extension Local Food Systems and Small Farms Team's website at:
http://web.extension.illinois.edu/smallfarm/ and the calendar of events at http://web.extension.illinois.edu/units/calendar.cfm?UnitID=629.

Regional Reports

From western Illinois ... The past few weekends have had exceptionally warm weather, just great for those of us who do most of our work on the weekends. We missed the snow of last week, but definitely felt the wind. The ground has gone from saturated conditions a few weeks ago to more workable conditions, allowing a few to get started with spring tillage. I noticed a few who have started to apply anhydrous ammonia late this past week as well.  Not all the fields are in the same condition, so farmers need to pick and choose fields accordingly before they start any tillage work.

The sunshine and warm weather can certainly heat up a high tunnel. The temperature was near 100 degrees before I had an opportunity to open up a side to vent over the weekend. One tomato grower who has 5 greenhouses with tomatoes sent me a picture of their first bloom, which appeared on Feb. 20th and is the earliest he has had to date. They have been alternating between running the evaporative coolers one day and firing up the gas heaters the next.

Matted row strawberries should be uncovered when ground temperatures are 40-42 degrees Fahrenheit and many locations should be close to that range now. Uncovering too early encourages early growth and early blooms, which are more at risk for a late frost. Uncovering too late may cause the plant to initiate growth under the straw.  Growth without the benefit of photosynthesis can deplete food reserves of the plant. When removing straw, leave enough to protect the berries from making contact with the soil. This can help reduce leather rot concerns as well as keep the berries cleaner.

We've removed the covers from our overwintering plasticulture strawberries. Winter dessication is about normal. We used either a single 1.5 ounce cover or a double layer of 1.0 ounce cover. We didn't really see much difference between the two covers in terms of the amount of dead tissue. Even though we used many buckets of bait, we still had some overwintering voles. We just can't seem to get rid of those devils.

We're still picking spinach from our tunnels, and with the increased warmth and sunshine, the plants have been growing again. Other than watering and watching for aphids, there isn't much work involved in keeping something growing during the winter in a tunnel.  The taste of winter spinach is unbelievable, as the plant produces a higher level of sucrose to help prevent winter injury. It's well worth your time to take advantage of some winter production.

Mike Roegge (217-223-8380; roeggem@illinois.edu)

From southern Illinois ... Despite some snow and blizzard-like conditions in southern Illinois early last week it is now beginning to feel like spring.  Our snow was very short lived as temperatures were in the 40s the following day.  This was followed by a very warm and sunny weekend that had temperatures in the 60s to around 70 with a very windy Sunday.  Since then, we have had some storms Tuesday morning, followed by a moderate cool down with highs now in the 50s for the most of this week, with the potential for more rain.


Current condition of plasticulture strawberries in southern IL 2/29/16. Photo: B. Colvis

The sun, wind, and warm temperatures did allow for some of the best conditions we have had in a while to get out into the field to do a "few" things.  I was able to mow off the asparagus variety trial I have here in Jackson County.  Last fall, I broadcasted cereal rye as a cover crop in the asparagus plot and got a fairly decent stand.  The cereal rye was just starting to green up and by mowing now I was able to do minimal harm to the cover crop.  It will grow for the next couple of weeks and provide some basic cover before spring burndown.  Other than pruning, it is has not dried out enough to do any tillage or other field work.  In the high tunnel at my office, we have been harvesting greens, and the carrots are really starting to put on some size.   Plasticulture strawberries are doing very well and starting to put on some good growth and branch crown development.  Some growers have even pulled covers off for a few of our warmer days, but the covers have not gone far as mother nature still may have some days left before spring.

Nathan Johanning (618-939-3434; njohann@illinois.edu)

Vegetable Production and Pest Management

Warm Winter Weather Sets the Stage for Corn Flea Beetles and Stewart's Wilt

Average winter temperatures in Illinois for 2015-2016 were much warmer than 2014-2016 (Figures 1 and 2). Warm temperatures during the months of December, January and February favor increased survivorship of the corn flea beetle and the bacterium it vectors. Corn flea beetles are the primary vector of Stewart's Wilt. Erwinia stewartii, the bacterium that caused Stewart's wilt, survives the winter in the gut of the corn flea beetle and the survival of the corn flea beetle is dependent on winter temperatures. Warmer winters result in greater survivorship of corn flea beetles, thus increasing the potential for Stewart's wilt. Using the average temperatures of December, January, and February, the potential for Stewart's wilt can be predicted (Table 1).

Table 1. Projected risk of Stewart's wilt based on the average temperatures of December, January, and February.

Average temperature of December, January, & February

Probability of early season wilt

Probability of late season blight

<27° F

Absent

Trace, at most

27-30° F

Light

Light to Moderate

30-33° F

Moderate

Moderate to Severe

>33° F

Severe

Severe

 


Figures 1 and 2. Average winter temperatures of 2014-2015 and 2015-2016.

Corn flea beetles become active in the spring when temperatures rise above 65°F, and they feed on and transmit Stewart's wilt bacteria to seedling corn plants. The bacterium can spread systemically throughout the plant. Although most commercial field corn hybrids are resistant to Stewart's wilt, the disease is still a concern for susceptible seed corn inbreds and many sweet corn hybrids.

There are two phases of Stewart's wilt: the seedling wilt phase and the leaf blight phase. The seedling wilt stage occurs when seedlings become infected at or before the V5 stage. The vascular system becomes plugged with bacteria, causing the seedling to wilt, become stunted, and die. Infections of older corn plants usually result in the development of the leaf blight phase of Stewart's wilt. This phase is characterized by long, yellow to chlorotic streaks with wavy margins along the leaves. When the late infection phase or "leaf blight phase" of Stewart's wilt occurs after tasseling, it is generally not a concern in sweet corn because ears are harvested before damage occurs.

Based on the recent winter temperatures from the Midwest Regional Climate Center, estimates of early season Stewart's wilt are shown in Table 2. Remember, however, that these are only predictions; numbers of surviving corn flea beetles are not known.

Table 2. Early season Stewart's wilt predictions, 2016.

Location

Average temperature
December 2015 - February 2016

Early Season Wilt

Freeport

28° F

Light

St. Charles

30° F

Light

DeKalb

29° F

Light

Monmouth

31° F

Moderate

Peoria

34° F

Severe

Champaign

34° F

Severe

Springfield

34° F

Severe

Brownstown

34° F

Severe

Belleville

39° F

Severe

Rend Lake

36° F

Severe

Carbondale

39° F

Severe

Dixon Springs

40° F

Severe

Kelly Estes, State Survey Coordinator, Illinois Cooperative Agricultural Pest Survey (217-333-1005; kcook8@illinois.edu)

Preparing for Corn Earworm, 2016

An updated version of my usual pre-season corn earworm management recommendations ...

Corn earworms are often the most damaging insects in sweet corn in the Midwest.  They overwinter in the pupal stage in the soil, but their survival rate is very low in most of the region.  This winter has been very mild, but even so, the local overwintering survival of corn earworm pupae is not likely to be the cause of heavy moth flights in most parts of the state or region.   Corn earworm manages to be a severe pest every year anyway because it migrates in from southern states on weather fronts every summer.  In much of the region the period of first activity (and the first need to control them) can vary from June through August, depending on the time of their migration and the availability of sweet corn that is silking.  Although control may be necessary in one portion of the region at a particular time, it may be unnecessary in many other locations.  Consequently, it really is essential to establish a monitoring program to determine spray needs.  Unfortunately, scouting for foliar damage or larvae on the surface of plants is not an option.  Corn earworm moths lay their eggs singly on silks, and larvae move down the silk channel immediately after they hatch from the eggs (and hatching can occur in as little as 2 ½ days during hot weather).  On corn, larvae do not feed on any exposed parts of the plant (leaves, husks, etc.), so the only practical way to kill them (short of having planted BT sweet corn, which does not provide 100 percent control) is with a contact insecticide applied to the silks.  Larvae crawl across the residues on the silks, and the insecticide is taken up through the cuticle.


Left: Corn earworm larva. Right: Hartstack trap.


Corn earworm moth (Kansas Department of Agriculture).

Effective monitoring programs depend on the use of pheromone-baited traps that catch male corn earworm moths and are used as indicators that adults of both genders are present and eggs are being laid.  Previously we have recommended using either a wire Hartstack trap (pictured above) or a nylon version of the same general design marketed by Scentry and several regional distributors.  We've long known that paper sticky traps are ineffective at monitoring corn earworm moths, and about a decade ago research indicated that the Scentry nylon cone traps do not really work well enough.  Results from monitoring work done in 2006 showed that the nylon traps also may fail to detect light but still significant flights when the wire Hartstack traps do catch moths.  Consequently, I now recommend that all sweet corn and seed corn producers use the wire Hartstack trap.  (Data to support this recommendation came from a regional monitoring effort coordinated by Bill Hutchison of the University of Minnesota and conducted by several entomologists and horticulturists who participate in the Great Lakes Vegetable Workers Group.)  Traps should be baited with Hercon "zealures," and the lures need to be replaced every 2 weeks.  Earworm control is necessary when moth flight is ongoing and fresh silks are present.  If traps are catching more than a few moths (3 to 10 per trap per night) when silking begins, sprays should be applied within 2 days after first silk -- insecticide residues must be on the silks to kill larvae immediately after they hatch from eggs and before they enter the silk channel.  If the only silking corn in your area is your field, the threshold for treating should be revised down to 1 moth per trap per night ... in your traps or those operated by your neighbors.

A Midwest supplier of the Hartstack trap for earworms is Bob Poppe, Route 1, Box 33, Lexington, IL, 61753 (309-723-3201).  I suggest that you buy an extra top cylinder for each trap to make handling more efficient.  Lures are available from Great Lakes IPM (10220 Church Road NE, Vestaburg, MI  48891; 989-268-5693; 989-268-5911; 800-235-0285; FAX: 989-268-5311).  The wire Hartstack trap is not cheap ... think in the $300 range plus shipping, and think higher numbers if the traps must be shipped a long way.  But before you let the price tag make you baulk, consider ...

Insecticide and "trait" choices for corn earworm control ... and there are some new Bt varieties for 2016

First, insecticides ...

What about Bt sweet corn varieties? 

Rick Weinzierl (217-244-2126; weinzier@illinois.edu)

2015 Illinois Farmers Market Price Reporting Summary

University of Illinois Extension Educators, Bronwyn Aly and Deborah Cavanaugh-Grant, began this project in 2014, collecting weekly price information from eleven different farmers markets across Illinois. During this first year, market reporters were asked to provide the average price for each crop being sold at the market. When the pricing information was being summarized at the end of the market season, it was realized that making price comparisons between markets on the different crops was going to be inaccurate due to variations in reporting quantities. As an example, comparisons for the average price per bag of spinach could not be made because the bag size varied or was not recorded. In order to report more meaningful pricing information to growers and consumers, the comparison quantities needed to be equal. Because of the vast number of fruits and vegetables that can be grown in Illinois, it became evident that the reporting system needed to be streamlined and made more manageable for reporters.

In 2015, data was collected from twelve farmers markets and one produce auction across the state; from Woodstock to Harrisburg and Quincy to Charleston. Each week, Extension Educators, program assistants and/or Master Gardener volunteers collected information on 20 crops. The lowest and highest price for each available crop was reported using standard measurable units (bulb, head, peck, pint, pound, quart, etc.). Using an online survey software tool (Qualtrics), reporters submitted their weekly reports. This information was then compiled into a weekly report that was sent to the University of Kentucky for posting on their webpage http://www.uky.edu/Ag/CCD/ILfarmersmarket.html as well as being linked to the University of Illinois Extension Local Food System and Small Farms website at http://web.extension.illinois.edu/smallfarm/cat139_4407.html. Table 1 is a summary of the lowest and highest prices for each of the 20 crops from all reporting markets. The last column lists the top ten marketed crops from 2015 from all markets. While this number is not meant to indicate the top crops grown in Illinois, it does give an indication of how many times these specific crops were sold at markets. A summary of the 2014 and 2015 pricing reports can be found as a pdf on the University of Illinois Extension webpage http://web.extension.illinois.edu/smallfarm/farmersmarket.html. The Illinois farmers market price reporting project will continue again during the 2016 market season, and we are currently finalizing the reporting form and participating markets.

Table 1. 2015 Illinois farmers market price report summary.

Illinois

2015 Farmers Market Price Report

Number of times reported

Top Ten Marketed Crops

Averages across all markets

12 Reporting Markets Markets

Low Price

High Price

Asparagus (lb)

$3.43

$4.30

24

 

Apples

 

 

 

 

(lb)

$2.01

$2.37

31

 

(peck)

$10.13

$10.27

15

 

Blackberries/Raspberries

 

 

 

 

(pint)

$4.21

$4.64

57

10

(quart)

$5.11

$5.25

14

 

Beans, Green (lb)

$2.39

$2.66

115

1

Broccoli (head)

$1.81

$2.25

54

 

Cabbage (head)

$1.80

$2.21

57

10

Cantaloupe (head)

$2.87

$3.48

37

 

Cucumber

 

 

 

 

Slicing (each)

$0.65

$0.86

106

3

Slicing  (lb)

$1.60

$1.60

10

 

Pickling  (lb)

$1.60

$1.82

17

 

Garlic (bulb)

$0.72

$0.89

62

8

Lettuce, Romaine (head)

$1.90

$2.26

44

 

Onions (red, sweet, white, yellow)

 

 

 

 

(each)

$0.82

$0.98

76

6

(lb)

$1.40

$1.64

46

 

Peppers, Bell

 

 

 

 

(each)

$0.63

$0.95

99

4

Potatoes (Red, White, Yellow)

 

 

 

 

(pint)

$1.99

$2.21

19

 

(quart)

$2.57

$2.76

35

 

(lb)

$1.43

$1.67

58

9

New  (pint)

$2.00

$2.00

7

 

New (quart)

$3.02

$3.21

31

 

New (lb)

$1.50

$1.54

14

 

Squash, Acorn

 

 

 

 

(each)

$1.14

$1.81

31

 

Squash, Butternut

 

 

 

 

(each)

$1.43

$2.13

29

 

Strawberries

 

 

 

 

(pint)

$3.47

$3.72

16

 

(quart)

$4.33

$4.65

26

 

Sweet Corn (dozen)

$4.63

$5.22

67

7

Tomatoes

 

 

 

 

Red Slicing (lb)

$2.05

$2.41

109

2

Cherry/Grape (pint)

$2.40

$2.85

46

 

Cherry/Grape (quart)

$3.57

$3.90

15

 

Cherry/Grape (lb)

$1.90

$2.00

5

 

Green Mature (lb)

$1.83

$1.83

21

 

Watermelon (each)

$4.24

$5.06

43

 

Seedless (each)

$4.54

$5.46

26

 

Zucchini

 

 

 

 

(each)

$0.74

$1.08

94

5

(lb)

$1.39

$1.55

20

 

Bronwyn Aly (618-382-2662; baly@illinois.edu)

Pricing Information and Marketing Resources

The following websites can be good resources for growers seeking more information on pricing and marketing.

2010 Guide to Selling at Farmers' Markets (published by Growing for Market) @ https://web.extension.illinois.edu/smallfarm/downloads/46912.pdf 

Farmers Market Coalition @ http://farmersmarketcoalition.org/education/qanda/

Market Farming Success - The Business of Growing and Selling Local Food, 2nd Edition, Lynn Byczynski @ http://www.chelseagreen.com/market-farming-success-revised-and-expanded-edition

The Packer -- Vegetable Commodity Pricing @ http://www.thepacker.com/vegetables/commodity-pricing

Pricing for Profit (article by Craig Chase, Iowa State University) @ http://www.agmrc.org/business_development/operating_a_business/direct_marketing/articles/pricing-for-profit/
Pricing Your Farm Products (created by the Rutland Area Farm and Food Link)  @ http://www.uvm.edu/newfarmer/marketing/marketing_resources/pricing_raffl.pdf
Rodale Institute - Organic Price Report @ http://rodaleinstitute.org/farm/organic-price-report/

Selling Farm Products at Farmers Markets (article by Matt Ernst, University of Kentucky) @ www.uky.edu/Ag/CCD/marketing/farmmarket.pdf

Understanding Organic Pricing and Costs of Production and other ATTRA publications @ https://attra.ncat.org/publication.html

USDA Agricultural Marketing Service, Fruit and Vegetable Market News @ http://www.ams.usda.gov/market-news/fruits-vegetables

University of Kentucky, Center for Crop Diversification @ http://www.uky.edu/Ag/CCD/

Bronwyn Aly (618-382-2662; baly@illinois.edu)

Food Safety Updates

Produce Safety Rule: AGRICULTURAL WATER QUALITY -- article 3 of 7

Agricultural water is defined, in part, as water that is intended to, or likely to, contact the harvestable portion of covered produce or food-contact surfaces.  The Produce Safety Rule establishes requirements for water sources and microbial quality of water, including periodic testing and actions to be taken when such water is not safe or of adequate sanitary quality for its intended use.  There are two sets of criteria for microbial water quality.  Both criteria are based on the presence of generic E. coli, which can indicate the presence of fecal contamination:

Water directly applied to growing produce (other than sprouts)

Water used during or after harvest

These two criteria are intended as a water management tool for farmers, for use in understanding the microbial quality of their agricultural water over time, and determining a long-term strategy for use of water sources when growing produce other than sprouts.  The FDA is exploring the development of an online tool that farms can use to input their water sample data and calculate these values. 

Questions/Comments:

The Food and Drug Administration has established a Food Safety Technical Assistance Network to provide a central source of information to support industry understanding and implementation: http://www.fda.gov/Food/GuidanceRegulation/FSMA/ucm459719.htm

Next article in the series will address Agricultural Water Testing

Laurie George (618-548-1446; ljgeorge@illinois.edu)

Less Seriously ...



University of Illinois Extension Specialists in Fruit and Vegetable Production & Pest Management

Extension Educators – Local Food Systems and Small Farms

Bronwyn Aly, Gallatin, Hamilton, Hardin, Pope, Saline, and White counties

618-382-2662

baly@illinois.edu

Katie Bell, Franklin, Jackson, Perry, Randolph, & Williamson counties

618-687-1727

klbell@illinois.edu

Sarah Farley, Lake & McHenry counties

847-223-8627

sfarley@illinois.edu

Nick Frillman, Woodford, Livingston, & McLean counties

309-663-8306

frillma2@illinois.edu

Laurie George, Bond, Clinton, Jefferson, Marion, & Washington counties

618-548-1446

ljgeorge@illinois.edu

Zachary Grant, Cook County

708-679-6889

zgrant2@illinois.edu

Doug Gucker, DeWitt, Macon, and Piatt counties

217-877-6042

dgucker@illinois.edu

Erin Harper, Champaign, Ford, Iroquois, and Vermillion counties

217-333-7672

harper7@illinois.edu

Grace Margherio, Jackie Joyner-Kersee Center, St. Clair County

217-244-3547

gracem@illinois.edu

Grant McCarty, Jo Daviess, Stephenson, and Winnebago counties

815-235-4125

gmccarty@illinois.edu

Katie Parker, Adams, Brown, Hancock, Pike and Schuyler counties

217-223-8380

keparkr2@illinois.edu

Kathryn Pereira, Cook County

773-233-2900

kpereira@illinois.edu

James Theuri, Grundy, Kankakee, and Will counties

815-933-8337

jtheu50@illinois.edu

Extension Educators – Horticulture

Chris Enroth, Henderson, Knox, McDonough, and Warren counties

309-837-3939

cenroth@illinois.edu

Richard Hentschel, DuPage, Kane, and Kendall counties

630-584-6166

hentschel@illinois.edu

Andrew Holsinger, Christian, Jersey, Macoupin, & Montgomery counties

217-532-3941

aholsing@illinois.edu

Extension Educators - Commercial Agriculture

Elizabeth Wahle, Fruit & Vegetable Production

618-344-4230

wahle@illinois.edu

Nathan Johanning, Madison, Monroe & St. Clair counties

618-939-3434

njohann@illinois.edu

Campus-based  Extension Specialists

Kacie Athey, Entomology

217-244-9916

kathey@illinois.edu

Mohammad Babadoost, Plant Pathology

217-333-1523

babadoos@illinois.edu