Illinois Fruit and Vegetable News:

A Newsletter for Commercial Growers of Fruit and Vegetable Crops
A Publication of University of Illinois Extension and the College of Agricultural, Consumer, and Environmental Sciences

Vol. 15, No. 4, April 29, 2009

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"We are what we repeatedly do. Excellence, then, is not an act, but a habit." --Aristotle

Address any questions or comments regarding this newsletter to the individual authors listed after each article or to its editor, Rick Weinzierl, 217-333-6651, weinzier@uiuc.edu. To receive email notification of new postings of this newsletter, call or write the same number or address.

In This Issue:

Upcoming Programs (Illinois Tree Nut Association spring meeting; SW Illinois Tree Fruit Twilight meeting; Mid-Mississippi Valley Orchard Tour; Grape Growers Workshop; Illinois Summer Horticulture Day; 2009 Sustainable Ag tours)

Regional Updates (from Jeff Kindhart and Bronwyn Aly, Elizabeth Wahle, and Maurice Ogutu)

Notes from Chris Doll (codling moth biofix; scab sprays)

Plant Clinic Opens (May 1 seasonal opening)

Degree-Day Accumulations

Fruit Production and Pest Management (managing winter damage in grapes; insect updates)

Vegetable Production and Pest Management (waiting to plant)

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

Upcoming Programs

• The Illinois Nut Tree Association spring meeting, May 2, 2009, at the Madison County Farm Bureau Building, 900 N. Hillsboro, Edwardsville, IL, with registration beginning at 10:00 a.m. A representative from Forrest Keeinng Nurseries will give a presentation on grafting and growing nut trees, and discussions about general culture and varieties will also be held. Lunch is a traditional pot-luck meal with lots of good nut desserts. Everyone is welcome, and I can give more information if needed at edwdollx2@aol.com or 618-656-1605. (Chris Doll)
• Tree fruit twilight meeting, 5:30 p.m., May 14, 2009, at Eckert's Grafton Orchard. From Grafton (IL-100), take IL-3 north about 2.5 miles to Otterville Road. Take a left onto Otterville Road, and Eckert's is approximately 1.3 three miles on the right. From Jerseyville, take IL-16 west to Otterville Road, approximately 3.4 miles. Turn onto Otterville Road and Eckert's is approximately 7.2 miles on the left.
• Mid Mississippi Valley Orchard andKSHS Orchard Tour, May 19, 2009, Reid's Orchard, Owensboro,KY. Contact Annette Heisdorffer 270-685-8480 or JohnStrang 859-257-5685.
• Grape Growers Workshop, May 23, 2009, at the Lazy L Grape Ranch, near Mechanicsburg, IL. The vineyard, owned by Brad Lindquist, is located east of Springfield, just south of Mechanicsburg. From I-72, take the Mechanicsburg Exit (#114) into Mechanicsburg. As you come into town, turn left (east) onto W. Main Street, then right onto S. Church Street, which turns into Roby Road. Continue south past Darnell Road and turn left (east) onto Moomey Road. The vineyard will be on the left (south) and visible from the road. Brad Taylor from Southern Illinois University and Elizabeth Wahle will discuss and demonstrate canopy management practices. The meeting will begin at 10:00 a.m., with registration at 9:30 a.m. Please contact Elizabeth Wahle if you plan to attend (for an accurate lunch count). Registration is $25.00 per person at the door and includes lunch. For further details, contact Elizabeth Wahle at wahle@illinois.edu or 618-692-9434. Grape Growers Workshops are sponsored by IGGVA, UI Extension, VESTA, and IDA.
• 2009 Illinois Summer Horticulture Day, June 11, Royal Oak Farm near Harvard, Illinois, beginning at 8:30 a.m. For more information and/or reservations call Don Naylor, Executive Secretary of the Illinois State Horticultural Society at 309/530-7678 or by email at ilsthortsoc@yahoo.com. To register in advance, mail a check for $25 per person to: I.S.H.S., 15962 Old Orchard Rd, Bloomington, IL 61705. Advance reservation deadline is the June 9. On-site registration is $30.
• 2009 Sustainable Agriculture Tours that involve fruits and vegetables:
  • June 19, Growing Strawberries, Naturally. Jed's Farm, Thompsonville
  • August 13, Creative Community Co-op Farming. Basu Natural Farms, Pembroke
  • September 22, Fresh Fruits and Vegetables. River Front Berry Farm, Martinton (http://www.riverfrontberryfarm.com)
  A fee of $20 per person will be charged for each tour, which includes lunch. Registration at least one week in advance is required. For more information on these and other tours, see https://webs.extension.uiuc.edu/registration/default.cfm?RegistrationID=2845. To register by phone, contact Donna Cray at 217-241-4644. For more information, contact Deborah Cavanaugh-Grant (217-968-5512; cvnghgrn@illinois.edu).

Regional Updates

At the Dixon Springs Agricultural Center, plasticulture strawberries are beginning to be harvested. We are seeing some thrips and some tarnished plant bug at DSAC in strawberries, and growers should remain vigilant in their scouting and fertility programs. Our blueberry crop still looks very good. In spite of a tremendous bloom, apple set was light on some varieties here.

High and low tunnel tomatoes continue to make growth and many growers were able to get plastic mulch laid and some early sweet corn planted during last weekend during a brief period of dry field conditions. Monday night's rain again brought field work to a halt, and the forecast appears to be for more rain to come. Growers having to hold tomato and pepper transplants longer than anticipated because they cannot get in the field should try to keep the greenhouse cool and reduce water and fertilizer to the absolute bare minimum to slow growth.

Jeff Kindhart and Bronwyn Aly (618-695-2444; jkindhar@illinois.edu, baly@illinois.edu)

In southwestern Illinois, there still is not a lot of field prep going on due to wet field conditions. This past weekend soil conditions were dry enough for field planting throughout most of the region, but rain came back at the beginning of the week. Temperatures that were well into the 80's last week resulted in the last holdouts in the landscape breaking bud. This week, temperatures are more normal for the season, with lots of rain in the forecast.

Peaches are in abundance for the most part and for some cultivars it took quite a while before fruit set was visible. As I mentioned in the last newsletter, some growers cautiously held off bloom thinning because of poor weather conditions during bloom but are now seeing good to excellent set for the most part and a lot of hand thinning in their future. Petal fall thinning in apples without bee kill is a rough go because of unevenness of bloom. Growers may need to wait for visible fruit set. Strawberry fruit set is tremendous this year; harvest started this week for some in the far south on plastic. Scouting for thrips is important with all the wind coming through; see the spray guide for control options with acceptable PHI's. Matted row growers are still at least three weeks away from harvest. Blueberries are in full bloom and set looks good so far. Brambles are well leafed-out and flower buds are visible. I have seen anthracnose in blackberries in more than one location now, so growers should be scouting canes for a purple rimmed circular lesion (see picture below). Grapes are budded out and this is the critical start of control for black rot and Phomopsis. For those of you who have one of the mancozeb products, begin applications after ½-inch shoot growth and continue according to the spray guide recommendations. Mancozeb is best at this time due to its highly effective control of Phomopsis, black rot, and downy mildew, and its 66-day PHI limits it use later in the season.

Anthracnose on blackberry.

Elizabeth Wahle (618-692-9434; wahle@illinois.edu)

In northern Illinois, weather has typical of April - all sorts of variability. Day temps have ranged from the 40s to the 80s, with night temps in the 30s to 50s. Rainfall over the last 10 days ranged 1.5 to 2 inches.

Apples are in tight cluster to pink, and apple scab, rust, and powdery mildew control spray programs are underway, as are efforts to control rosy apple aphid, San Jose scale, tarnished plant bug, and spotted tentiform leafminer. Sour cherries are at petal fall, and spray programs for controlling brown rot, cherry leaf spot, and powdery mildew are going on.

Wet conditions have limited most field work, but some growers have planted cabbage, potatoes, sweet corn, and other cool season vegetables. Warm season vegetables such as tomato, peppers, cucumbers, and melons seedlings started in greenhouses are thriving.

Maurice Ogutu (708-352-0109; ogutu@illinois.edu)

Notes from Chris Doll

The area remains fairly wet from near-normal rainfall of 3.3 inches, but the warm and windy weather of April 23-26 helped with soil drying so that a few field crops and vegetables have been planted. Luckily it was dry for about 144 hours of the windy weather, so that the need for fungicide sprays was diminished somewhat. It was during this period however, that codling moths emerged in some orchards and biofix dates range from April 23 to 27. In contrast, my traps remain empty. In one orchard, the traps were empty when the bees were removed on the night of the April 23, and averaged 10 moths per trap 24 hours later. On the 28th (five days later), these traps averaged 26 moths per trap, with 59 in one trap.

There is enough tag-bloom on Jonathans and Goldens in most orchards to cause concern about fireblight infections from predicted rains. However, uptake of strep in observation orchards appears to have been good and yellow symptoms were easy to find. No visible apple scab lesions (peaches either) have been seen, but today's concern is about the full bloom of the cedar apple galls in neighboring tress. Protective sprays are suggested ahead of infectious conditions.

Only a trace of rosy apple aphids has been seen, and chewing insect damage was minimal on some young apple trees. However, a block of apple trees that were sprayed with 3 percent dormant oil at green tip have some surviving scale which will require continued control efforts.

Matted row June bearing strawberries are in full bloom and some of the brambles are showing flower buds. A little more time is needed to determine fruit set in tree fruits and the need for thinning.

Chris Doll

May 1 Opening of University of Illinois Plant Clinic

It's that time of year ... The University of Illinois Plant Clinic at the University of Illinois opens again for the season on May 1, 2009. The University of Illinois Plant Clinic provides a service to the general public, offering unbiased plant problem diagnosis and access to opinions of specialists in multiple disciplines, funneled through one location. There is a support fee for all plant samples.

For those of you who have never used the Plant Clinic services, a web site with details can be found at http://plantclinic.cropsci.illinois.edu/. There are few changes from the 2008 season. One that is probably not too surprising is an increase in sample fees. We have not increased fees for over 10 years; and the increase this year is minimal. Basic samples, including those needing laboratory culturing, are now $15.00 (previously $12.50). Both pinewood nematode and soybean cyst nematode samples are $20.00. Complete soil nematode assays remain at $40.00. If you plan to send soil for a complete nematode analysis, please call first at 217-333-0519. All sample fees are required with the sample.

When submitting a sample for diagnosis, be sure to include live, symptomatic tissue. It is always a good idea to send a healthy portion along with the affected, but that is not mandatory. A specimen data form is required with each sample. Forms are available on our web site or in extension offices. The more information provided, the better we can accurately assess the problem. Feel free to include photos or a disc of digital images with the sample. These are particularly helpful with fruit and vegetable samples because they may change drastically in the mailing process. It helps to know what was observed in the field. We generally prefer three pictures: one picture of the entire planting or landscape, one of the entire affected plant, and a close-up of symptoms. Always take pictures with the sun at your back. Send only clear images. Remember, if the pictures are blurry for you, they are still blurry when they arrive at the Plant Clinic.

The Plant Clinic processed 2,434 plant samples in 2008. Only four diagnosticians were employed to handle plant samples, but an additional 19 campus specialists provided input from disciplines that included weed science, nematology, plant pathology, entomology, horticulture, and agronomy. Additionally, 850 telephone inquiries, 505 walk-in diagnoses, and over 500 electronic inquiries were processed through the Plant Clinic from May through mid-September. We look forward to another productive year in 2009. If you have specific services or testing needs, let me know at npataky@illinois.edu. We can provide ELISA testing for many pathogens and will accommodate for specific tests when there is a need.

Nancy Pataky (217-333-0519; npataky@illinois.edu)

Degree-Day Accumulations

Degree-day accumulations presented below for weather stations in the Illinois State Water Survey WARM data base have been summarized using the Degree-Day Calculator on the University of Illinois IPM site (http://www.ipm.uiuc.edu/degreedays/index.html). The list below includes only degree-day accumulations and projections based on a 50-degree F developmental threshold and a January 1 starting date, but other options that use different thresholds and specific biofix dates are available on the Degree-Day Calculator. The degree-day calculator is available as a result of a joint effort of current and former extension entomologists (primarily Kelly Cook) and Bob Scott of the Illinois State Water Survey. If you have questions about how to use the site, contact me or Bob Scott (rwscott1@uiuc.edu).

Degree-day accumulations, base 50 F, January 1-April 28, 2009 (left), and projected through May 5 (center) and May 12 (right).

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

Fruit Production and Pest Management

Managing Winter Damage in Grapes

In many cases grape growers in northern Illinois will have an additional chore in their vineyards this season; retrain damaged vines. While there are some great exceptions, some varieties planted in northern Illinois vineyards were too tender for this winter's temperatures. At the St Charles Horticulture Research Center on the western perimeter of the Chicago metropolitan area, the seasonal low was -27oF on January 16. Many varieties in the screening trial were damaged at the Research Center. Temperatures were colder further west and north, with some sites known to be -35oF and some possibly colder in northwestern Illinois. While these are very cold temperatures, they did not break a record. We will probably see these temperatures again.

We know that damage did occur in some vines. One reason I know is that I sampled canes from vineyards around the northern end of the state and cut buds to assess bud damage. The results were good news and bad news. The hardier varieties from northern breeding programs, particularly those hybrids with significant Vitis riparia background, were hardy enough to have significant primary bud survival. These included varieties like Marechal Foch, Marquette, Frontenac, Leon Millot, LaCrosse, and St Pepin. But hybrid varieties that are considered tender, such as Seyval Blanc, Chancellor, Corot Noir, Landot Noir and Noiret suffered extensive primary bud loss. Even more concerning was that secondary bud loss was also extensive. Clearly these vines do not have the genetic hardiness to withstand such cold temperatures.

'Chancellor' dieback and regrowth.

But this isn't the whole story. Other forms of winter damage were not evaluated. This would be damage to permanent structural wood, including cordons and trunks. This is damage to the cambium layer underneath the outer layer of bark. If the temperatures are cold enough, patches of damage in the cambium die, leaving the water and nutrient transport system compromised. If the damage is extensive enough, the trunk or cordon is girdled, resulting in death above that point. Thankfully we had a generous layer of snow on the ground, so vines should recover. Grape vines develop large numbers of latent buds which "awaken" when death occurs above them in the cambium layers. They break out and begin to grow as replacement wood for the damaged wood. Those buds covered by snow should begin to break out in late spring, providing an opportunity for growers to retrain their damaged vines.

Growers should ask themselves whether it is a sound decision to retrain vines rather than replace them. It's a complicated business decision, involving forecasting of future weather events, suitability of the variety for profitability, winery preference for wine grape varieties, and opportunities for replacing the variety with a better, hardier variety. It's a good time to consider vineyard business risk management.

Another issue that may arise from winter damage, particularly in structural wood, is crown gall. Crown gall is a disease resulting from a bacterium, Agrobacterum tumifaciens, which takes advantage of the vines effort to heal damaged cambium. It overtakes the genetic machinery of the fresh cellular growth and "retools" it to redesign the growth to its advantage. The result is the production of galls in the damaged area and the slow death of the vine by girdling. These vines may be recovered if fresh growth from below the galls results. The vine can be cut off below the diseased wood and retrained from fresh growth, but the question remains, is it a good business decision to continue growing that variety? For more information on crown gall, see this publication from Cornell University; http://nysipm.cornell.edu/factsheets/grapes/diseases/crown_gall.pdf .

Growers who decide to continue to grow the damaged vines will need to wait until the plant initiates the recovery process, looking for signs of where the damage took place. Usually the vine will show its most vigorous growth just below the point of damage. A vine which shows weak growth at the end of one cordon but pushes its most vigorous shoot a few inches away from the trunk probably had damage occur in the cordon just past the vigorous shoot. Likewise, a plant which shows weak growth in both cordons and has a burst of vigorous shoots just below the snowline from the cold weather event probably has a damaged section of trunk. The areas beyond the damage will not recover. They may well develop crown gall. Often, if nothing is done, these plants will look somewhat productive, sometimes even setting a nice crop. But they usually collapse and die suddenly midseason. This seriously complicates recovery and may make it futile.

These vines should be retrained as soon as it's clear they are damaged. The damaged portion of the vine should be cut off, and the new shoots trained to replace the permanent wood. The good news is that because the plant still has its large volume of roots, it will grow rapidly. The vine should be able to replace the damaged structural wood in one season and be ready for production the following season. It might be best to plan a light crop the next season to give the vines plenty of opportunity to bulk up. But the good news is that the vine is well on its way to recovery and productivity.

This was a bell-weather season for the northern Illinois grape industry. It certainly tells us the degree of extremes we face from winter temperatures, those temperatures were not really unusual. As cold as it was, it was really only two nights in January that were damaging, one much worse than the other. I recall one week in January in the mid-90's which had 5 nights colder than minus 20oF at St Charles. These events are normal in our climate. Consider this information as you think about analyzing risk management for the business of growing grapes.

Bill Shoemaker (630-584-7254, wshoemak@illinois.edu)

Notes on Tree Fruit Insects

• Oriental fruit moth first generation flight continues. Setting a biofix date has been a little difficult in some locations, as moths were captured as early as April 1 south of Murphysboro, but then traps went empty until April 18. In terms of trying to predict population dynamics and timing of subsequent flights, it is likely that very few surviving larvae resulted from the very light early flight, so in terms of predicting second generation flight, using an April 18 biofix date there is probably accurate enough (followed by continuing the use of pheromone traps observe flights and time spray applications). Biofix for OFM in Calhoun County was set at April 15 ... and of course it seems counter-intuitive to see an earlier date for Calhoun County than Jackson and Union counties to the far south. We also captured moths here at Urbana by April 20, so the south-to-north difference in starting dates for OFM phenology models is very little as a result of the spring's odd weather patterns. Where insecticides are to be used against OFM, the Pennsylvania Tree Fruit Production guide (http://tfpg.cas.psu.edu/294.htm) offers the following comments: "Timing of broad-spectrum insecticide sprays for the first and second generations on peaches are as follows: first generation--150 to 200 and 350 to 375 degree-days (base 45F) following biofix; second generation--1,150 to 1,200 and 1,450 to 1,500 degree-days; and for the third generation, 2,100 to 2,200 and 2,450 to 2,500 degree-days for peaches and 2,450 to 2,500 and 2,900 to 3,000 degree-days for apples. The differences in larval development due to feeding on various food sources (i.e., terminals, fruits, apple, peach) and possible adult movement between adjacent apple and peach orchards contribute to significant overlapping between generations late in the season. Using pheromone traps to monitor the OFM population in each block is necessary to assess the potential problems caused by this pest." Where mating disruption is to be used for controlling second and third generation OFM in peaches using Isomate OFM Rosso, "ties" should be applied before the start of second generation flight (approximately 950 DD -- base 45F -- after first generation biofix).
• Codling moth biofix for the far south through Calhoun County appears to be somewhere between April 23 and 26 -- the warm weekend that just passed. Egg hatch begins around 220 degree-days (base 50F) after biofix. See page 30 of the 2009 Midwest Tree Fruit Spray Guide for recommendations on the timing of first sprays for codling moth control depending on the insecticide to be used.
• Grape berry moth flight is underway in far southern IL. A couple of good fact sheets on grape berry moth are available from Virginia (http://www.virginiafruit.ento.vt.edu/GBM.html and Michigan (http://www.grapes.msu.edu/grapeberrymoth.htm and http://web1.msue.msu.edu/vanburen/grpmth.htm). Controlling first generation grape berry moth is often not necessary; controlling later generations is more important.

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

Vegetable Production and Pest Management

Still wishing for dry weather and chances to plant ...

Less seriously

Little Johnny ...

Little Johnny's kindergarten class was on a field trip to their local police station where they saw pictures tacked to a bulletin board of the 10 most wanted criminals. One of the youngsters pointed to a picture and asked if it really was the photo of a wanted person. 'Yes,' said the policeman. 'The detectives want very badly to capture him.' Little Johnny asked, 'Why didn't you keep him when you took his picture ?'

Criminal behavior ...

Two convicts were sitting on their cots in a prison cell. One says to the other, "I hear you're getting out in a few days. Tell me something, are you going straight, or are you going back into politics?"

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

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