VERMONT VEGETABLE AND BERRY NEWS, July 15, 2003
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967 or vernon.grubinger@uvm.edu
www.uvm.edu/vtvegandberry

REPORTS FROM THE FIELD (as of July 14)

(Burlington) Picked first corn on July 10 that was transplanted in early May.  I think the moderate night temperatures helped move it along earlier than I have ever had!  Some lettuce bolting in the heat...not enough irrigating. Hot season crops are jumping out of the ground, tomatoes, peppers, melons, corn all looking great right now.  I used Entrust (spinosad) for first time on CPB. Very effective. Certainly a broader spectrum killer than BT, but with no organically-approved BT for controlling potato beetle we decided to try Entrust.

(Monkton) We have just about completed a great strawberry season, after putting 4 acres on drip irrigation and wondering in the spring if we would ever use it we have been  pleased with the ease of watering and felt it kept berry rot at a minimum.  Fruit flavor was exceptionally good. We started the season experiencing a fair amount of sunscald and Botrytis on king berries, but it completely disappeared in the later berries, indicating it was probably a weather-related problem. We have also seen more strawberry sap beetles than ever before but think it is directly related to that early season berry problem. Raspberry season is upon us, with a much lighter crop than last year due to winter injury. Thank goodness for Killarney and Taylor which come through in a year like this. Lauren and Canby had a lot of winter damage.

(S. Royalton) I've been using Surround, the clay-based insecticide product, and it appears to be making a huge difference. Hardly any cukes beatles (except on pigweed), only a trace of leaf hoppers on my spuds, and the flea beatles are all over my broccoli transplants as normal but are doing no damage.  Life is good. Everything is on a normal schedule.  Picked my first field tomatoes, and a ton of eggplant and peppers.  Planted corn is chest high and cruising, even without the moisture it needs.

(Starksboro)  I have 2 potato patches this year. One, the vast bulk of the acreage, is about 400 yards from last yearís patch. This is my normal rotation distance. The other is a small patch, about 100 feet in the opposite direction from last yearís. Both have had the same controls applied. The patch nearest last yearís has tremendous CPB pressure, and I expect yield to be significantly reduced by the resulting defoliation. This clearly demonstrates what an enormous effect rotation distance has on CPB control.

(Plainfield NH) Wrapping up a better than anticipated strawberry season. Plants look good going into renovation, and we got some good much needed rain last Friday. Just starting to  pick transplanted corn. Melons and direct seeded corn look way late. Field tomatoes hopefully will come in normally if weather stays warm. The drought and hot weather we experienced during the last 5 weeks really brought into focus the true cost of irrigation: fuel to run the tractors to run the  pumps and labor shuffling travelers and solid set pipe around. Irrigation is an extremely  expensive component of our production. When itís hot and droughty you irrigate and that seems to be it, no weeding or cultural niceties. I woke up to a rainy day Friday and felt someone had just  cut me a check for a huge sum of money.

(Plainfield VT) What a great strawberry season!  The best in 10 years for me. Cavendish yielded heavily for a week of picked fruit and a week of pick your own. Week three features lots of uneven ripening and TPB damage, so we have lowered our PYO price. The rain and cooler weather of last week were perfect.  I'm glad that this summer isn't day after blazing day. Harvesting lots of greens and peas. Demand is solid and prices are up over last year. Spent a small fortune on hand weeding carrots. Crab grass (barnyard grass?) seemed to come out of nowhere to be a major problem. Flame weeding has no effect on it, and it germinated eagerly in the heat wave. I will try summer fallowing to clean up a piece for next year's crop. Spraying for CPB and leaf hopper in potatoes, which overall look great. Flea beetles still a problem on Asian greens, row cover or not. Still planting for another two weeks, looking forward to a slightly less intense work pace.

(Brandon) Crops taking off in the heat, and enough rain came this past week to supplement what we had been putting down with pipe and pump. Strawberry crop fantastic, with both yield and size of berries up. No spray for TPB, as numbers remained just below threshold till late enough that I would not bother spraying.  A full four weeks of picking finishing up July 15. Started picking transplanted corn July 12 (no plastic, just bare ground and row cover). Ears full size and tips filled. Main problem has been relatively heavy pressure from ECB. The craziness of berry season precluded timely spraying of BT, and it seems there was a late egg laying right in silk. Result is some tiny borers just inside tips...easy to flick off when sorting, but still a pain. Very little side entry (<2%).  Size of ears about 10 to 15% larger from single transplants (one per cells), though the double transplants (two plants per cell) have been very nice and consistent, not to mention quick picking.

(Killington) We're picking sugar snaps, zucchini, summer squash, hoop house tomatoes, lettuce, garlic scapes, spinach, and cut flowers. Weeds are growing rapidly but we are gaining on them.  Flea beetle and cucumber beetle are under control. Cucumber and zucchini plants were covered with row cover until plants needed to be pollinated. We were drying up and the pumps were running prior to this rain. Farm store doing well with vegetable, eggs, and meat sales.

(Wilmington) We will need pumpkins this year please e-mail me or call with your wholesale prices, delivery schedule and estimated time frame for availability. boydfarm@sover.net or 802-464-5618.

(Wolcott) Long anticipated rain finally arrived. Everything has been growing fast with almost 3 weeks of 90 degrees but itís been getting dry. Seed crops are coming along well with our first seed crop, chives, just harvested. Next will be arugula in 2 weeks, followed by spinach, broccoli, pac choy, tat soi, and perennial flowers and herbs. We have watermelons 2" across which is large for me by this time. Love that heat. The trial gardens are full and beautiful and we've been having many visits for our lettuce taste testing of over 80 varieties. Later in August cut flower growers will be invited to see the 55 sunflower types and 30 zinnias. We are also we are trialing spinach, chard, beets, kale, lettuce, bell peppers, and basil Anyone reading this is invited especially if you are a commercial grower who can share your valuable feedback. We are also working on several open pollinated breeding projects of crops that are dominated by hybrids on the market such as broccoli, spinach and green and red bell peppers. Hopefully within a few years we should have OP's that rival hybrids in earliness, yield, flavor and disease resistance. Please give a call if you want to visit or join our informal group of farmer evaluators. Tom, High Mowing Seeds. 802-888-1800

(Charlotte) What a great year for weeds. Growing conditions are great on the whole. Had first cherry tomatoes from greenhouse. Squash bugs have appeared, but are little problem. Onions doing great and have some already 3 inches across. Garlic seems slow to head up, but getting there.  Lots of flowers blooming short but will even out as the season goes I imagine.  Trying greenhouse melons, but had to foliar feed a bit.

(Grand Isle) We recently hosted an Old Fashioned Strawberry Social with proceeds going to the local rescue squad.  The day was a success with 300 people attending.  The PYO berry season has come to a close. The cedar wax wings arrived for a miserable week and then took off for greener pastures (redder fruit). We started harvesting transplanted corn (Seneca Horizon) on July 14th. Our greenhouse tomatoes have a bad case of sunscald.  Fortunately we have not seen spider mites or experienced white mold.  There are lots of tourists in our neighborhood and sales have been excellent.

UVM PLANT DIAGNOSTIC CLINIC REPORT (Ann Hazelrigg)

Iíve seen a lot of berry rot on some strawberry varieties, possibly due to sun scald or maybe there was a missed fungicide spray during bloom when there was so much rain. Foliar leaf spot diseases should be showing up now on tomatoes due to warm weather and scattered rains. This is now the true disease season. Powdery mildew identified on cut flowers and I am sure that a lot of squash is infected now too although have not seen it in the lab. Seeing leafhoppers on potatoes and beans. In greenhouse tomatoes I have seen a heavy infection of leaf mold, Fulvia, due to poor ventilation and susceptible variety. I am seeing symptoms of bacterial canker on greenhouse tomatoes. Watch for curling of foliage and scorch symptoms on leaves. There may not be any outward symptoms of black cankers on the stems, but if you cut into the stem, there is black to brown streaking in the vascular system of the plant. These should be immediately cut off and removed from the greenhouse. Be sure to scout often in tomato houses for this disease. It can be seed borne and spread when removing suckers. It is a nasty one! if growers suspect this disease, I would like to try and isolate it from the tissue. Send sample to the PDC at Hills Building, 105 Carrigan Drive, UVM, Burlington, 05405.

VEGETABLE PEST UPDATES (adapted from John Mishanec, Eastern NY IPM, and Ruth Hazzard, UMass Vegetable Notes  - see www.umassvegetable.org/newsletters/

*  European Corn Borer (ECB) trap catch numbers in sweet corn are variable around the region, and you should scout your own fields to determine the pest pressure. Scouting is easy and pretty quick. (Just looking for ECB damage is NOT the same as scouting. You will always find ECB damage when you look for it. When you scout, you are estimating the percentage of damage so you can decide whether to spray.) To scout, examine 5 plants at 10 places in a field. Donít bother to scout fields that are still in whorl stage, since sprays will be ineffective until after tassels start developing. Look for small shot holes with frass and windows in the leaves where the larvae have not chewed all the way through. The typical threshold for spraying at tassel is 15% of plants showing damage. Depending on your markets, you may need to use a lower threshold or you may feel a higher threshold is acceptable.

* Corn Ear Worm (CEW) has been caught only in low numbers in western NY, coastal ME and southeastern MA , but it is time to be vigilant if you have silking corn. Use your own pheromone traps or pay close attention to trap catch reports elsewhere, especially when coastal storms occur.

*  Powdery mildew (PM) is infecting summer squash and zucchini. Scout all vine crops, paying attention to lower, older leaves for light green to yellow blotches on the upper surfaces, or a white to gray, powdery covering on the upper or lower surfaces. The end of July and first half of August is when powdery mildew usually shows up in pumpkin and winter squash. If applying fungicides, begin as soon as powdery mildew is observed, and continue at 10-day intervals.  To avoid resistance to fungicides, alternate classes of materials (rotate Quadris or Flint, both strobilurins, with Nova, also a systemic but with a different mode of action) and use a broad-spectrum fungicide (eg chlorothalonil) as well.  Do not use one class of fungicide more than twice per season, and use a non-systemic fungicide at the same time to reduce the chance of resistance. Organic growers can use a bicarbonate product like Armicarb.

*  Striped cucumber beetle numbers are down. Watch for squash bug adults, eggs and nymphs.

*  Potato leaf hopper (PLH) has arrived. In addition, when alfalfa and hay is cut, PLH often moves into other crops. Damage caused by PLH includes stunting, brown leaf margins, leaf curl, and reduced vigor. To avoid economic loss control PLH before such symptoms are visible. Scout potatoes, beans, eggplant and many other crops for the adults which are 1/4 inch long, light yellow-green, and fly up from foliage when disturbed. Also look for light green, wedge-shaped and fast-moving nymphs on the underside of leaves. Both adults and nymphs cause damage.

* Cabbage Ďwormsí are becoming active in the region: Diamondback moths (DBM), imported cabbage worms (ICW) and Cabbage Loopers (CL). Scout for these caterpillars on leaf undersides and on inner most portions of plants in addition to looking for feeding damage. Tiny holes are  easier to spot than tiny worms. Apply controls when caterpillars are small, and direct spray to leaf  undersides. Use at least 50 gal/A of water to achieve good spray coverage, and use a spreader-sticker. A threshold of 15% of plants with at least one caterpillar (of any species) is recommended for any heading cabbage, broccoli, and all leafy greens.  Before the cupping stage in cabbage and broccoli use a threshold of 35% plants infested. These thresholds lead to a clean crop at harvest. There are new insecticides available in addition to those which have been labeled for caterpillar control for a long time. These include SpinTor (Entrust for organic growers), Avaunt, Confirm and Proclaim. It is possible to get excellent control of caterpillar pests using these low-risk products that are relatively safe to handle and also conserve beneficial insects (which help suppress aphids and caterpillars).  It is also easier now to rotate among different types of products to prevent resistance to any single product. The cost of these new products ranges from $7 to $20 per acre, depending on high or low rates, compared to $5 to $12 per acre for synthetic pyrethroids, $5 to 21 per acre for carbamates, and $3 to $17 per acre for BT products.

* Late blight in potato has not been reported anywhere in the Northeast. This is good news, given that conditions have been good for development of the disease. Growers and scouts need to remain vigilant for the symptoms of late blight in the coming weeks.

*  Bacterial canker is a serious disease of tomato and symptoms occur both internally and externally. It is easy for this bacteria to enter and spread to adjoining plants, so down-the-row occurrence can be expected. This disease is highly infectious, and can contaminate hands, stakes and string used for trellising. Do not work in crop when foliage is wet. The use of copper mixed with maneb can be used to lessen this external movement. Plants are also infected internally, and browning of the vascular tissue is prominent at the nodes. Sprays will not affect this stage of the disease. Prevention of this disease includes Clorox or hot water treatment of seed before planting.

* Aphids in peppers do not require control unless populations get quite high. Usually predators such as ladybeetles, lacewings, and aphid parasites keep aphid numbers under control. By killing these good bugs, unnecessary broad-spectrum insecticide sprays, especially synthetic pyrethroids, can actually cause aphids to build up later in the season. To monitor aphid populations examine the underside of four leaves per plant on 25 plants. Count aphids up and divide by 100 to get  average aphids per leaf. Threshold for control is 10 aphids per leaf. See New England Vegetable Management Guide for recommended materials.

Mention of pesticides is for information purposes only. No endorsement is intended nor is discrimination against products not mentioned. Always read the label.

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