VERMONT VEGETABLE AND BERRY NEWS, August 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 August 11)

(S. Royalton) We've been picking melons for over a week, and with sweet corn in, we are at full ‘market strength’. Disease is spreading like mad through onions, tomatoes, and melons. I am getting myself pumped for the next few weeks of picking potatoes, and carrots, and onions in mass along with all the other stuff. My manageable schedule now will soon be a nightmare.

(Plainfield NH) This  has been a vexing year. Six weeks ago we had no rain and were irrigating all the time, now we cant find the pipe in the weeds. The muggy wet weather has us spraying all the time for blight and powdery mildew. Our corn scout has us spraying all the time for insect pests (see article below) and we still have two-spotted spider mites in the peppers. The weather is so hot and muggy even our Jamaicans are beginning to grumble. Spinach and beet greens are getting rotten and snotty. But we are picking field tomatoes, cherry tomatoes, melons and all manner of summer vegetables. We had a pretty good strawberry crop and the blueberries are very good compared to the horror stories I have heard from some growers. It was a first year with summer raspberries and although we picked some for our farm stands we have a lot to learn about growing and managing them. Still working on  strawberry bed renovation. I had an older bed I wanted to milk one more year then found out of has infestation of root weevil.

(Starksboro) We’ve had 7 inches of rain in the last 4 weeks and it’s having deleterious effects. At first it was very welcome, after a spell of very hot dry weather, but now we’re starting to show rots in some of the denser plantings. I was being quite cavalier about not spraying tomatoes in the dry weather, but since the rains started I’ve been trying to stay on a 7 to10 day frequency. Wet leaves and temperatures between 60 and 80 are optimum for early blight.

(Norwich) Constant rain and humidity causing lots of problems. Lettuce and broccoli taking it pretty bad, but water sure is cheap fertilizer! Early copper spray seems to do a very good job protecting melons etc. from powdery mildew. Haven't seen any on sprayed crops. Wow! Entrust (spinosad) is a silver bullet on CPB. Maybe it will help with TPB?

(Shaftsbury) Here in southwest Vermont the sun shines all day and we get half an inch of rain every other night..... and then I woke up and it was still raining. We are still seeding lots of fall crops: spinach, beet greens, arugula, radishes, baby bok choi, broccoli raab, last bean, last lettuce this week, purple top turnip, baby red turnip. Other fall crops look good though the rain is keeping us from timely cultivation, so there will be extra hoe work when it lets up. Flea beetles out strong as are TPB in broccoli. Excellent summer broccoli. variety for us this year is 'Gypsy' from Johnny's.

(Argyle, NY) With the constant, almost daily rains - 4 inches the past 10 days - the spinach has collapsed and field seedings have been impossible. The onions have a little downy mildew, but the size of all varieties is tremendous; the apples are looking large also and Redfree will be ready next week. The blueberry crop is small due to heavy winter damage. Our first woodchuck destroyed over 1000 heads of mature lettuce in a matter of a few days and caused us to be without lettuce for a few markets, which hasn't happened in 8 years. That's what we get for going away for a day and a half to visit family! Carrots rotting in the fields is another issue, but the younger folks are having fun harvesting in the muck--the most mud we've ever seen during harvests in 15 years of farming. Fun on the farm-- glad we have a large diversity of crops!

(Killington) A great growing season. Our farm stand is supplied by a large hoop house for tomatoes which we started harvesting in late June. Three large raised beds, which dry out early in the spring, and continue to provide good drainage during this wet growing season.  As one crop finishes up, we have transplants ready to pop in the ground including broccoli, lettuce, Asian greens, sugar snaps, etc.  This method provides a good selection of product from a small controlled area.  Low pressure from insects, but weeds are growing well.

(Dummerston) It's been raining so long my field workers have noticed webbing forming between their toes. The last two storms have brought Charley Earworm Moth and the family to vacation in my sweet corn silk. They brought plenty of friends, too. We told them to get out of town before noon but had to go after them with the Zealator oil gun. The Zealator pays off in rainy weather and high moth counts as you only have to do it once and the oil/Bt is not affected by the rain. Spraying copper whenever there's a break in the moisture and that's not often enough. Most crops somehow doing well but lettuce is starting to bottom rot. Trying to squeeze in a few more warm weather crops like beans, cukes, summer squash as we picked everything last year before it got frosted. Mums and cool weather flowers fine in the greenhouses, should sell well to replace the many washed out summer gardens. Irrigation pump is lonely. Need some sunny days to put everyone in better buying mood.

(Wilmington) Looking for pumpkins for  delivery mid-September. Please e-mail or call with
price. boydfarm@sover.net  or 802 464 5618.

UVM PLANT DIAGNOSTIC CLINIC REPORT  (Ann Hazelrigg)

The past couple of weeks I have seen a lot of powdery mildew on leaves and even on pumpkin handles. Bacterial speck on pepper due to a lot of overhead irrigation. Lots of early blight on lower leaves of tomatoes. Thrips and Alternaria on onions. Also lots of damage due to potato leafhopper on potatoes. Reports of severe blossom drop on peppers as well as small pepper fruits aborting due to heat? drought? birds? Also club root in cabbages, look for wilting in the upper parts of plants and pull up roots to check for knobby growths. Managing this disease requires a long rotation out of crucifers and good control of cruciferous weeds (mustards).

I have diagnosed 2 cases of bacterial wilt in cucurbits. Black speck or pepper spot is showing up in wrapper leaves of cabbage. This is a nonparasitic disorder of cabbage of unknown origin.  Symptoms include individual black specks, randomly distributed over the leaf.  Lesions are usually about 1 mm in size. Suspected causes include high rates of fertilizer, cultural conditions promoting vigorous growth and temperature fluctuations. High rates of potassium in the soil have been shown to significantly reduce the severity of the disease.  A quick web search showed a few varieties of cabbage that have tolerance to the disorder. Johnny's has one called Vantage Point but others are out there. I have not heard of any Phytophthora blight on pumpkins even though we have had some torrential rains. I imagine we are not seeing it because the rain has soaked in for the most part without waterlogging the soil. We may see it soon if ‘susceptible’ fields do not dry out.

Lots of reports of leaf mold and severe Botrytis (gray mold) in greenhouse tomatoes due to high humidity. Some Sclerotinia (white mold) in greenhouse tomatoes causing a tan dry rot at the base of the plant with wilting above. Split open the base to look for the sclerotia (hard black overwintering and long term survival structures.)  Remove plants by cutting off at the base and putting in a plastic bag.  I have also seen bacterial canker in greenhouse tomatoes. This also causes a wilt in plants often with no outward signs of the disease although there may be long black cankers on the stems. If you cut open the stem you will see browning in the vascular or water conducting tissue and if a section of stem is put in water, it is possible to see white clouds of bacteria streaming out of the tissue. Remove from the greenhouse being sure to not touch or sucker any other plants after handling.

MESSAGE FROM THE PRESIDENT (David Marchant)

There are two exiting marketing initiatives, that the Agency of Agriculture has undertaken.  The first is a Public Television show that will feature local chefs and growers promoting local berries and fall vegetables. Bruce Martell is organizing the program, and is similar the one they did promoting Vermont Maple in the Spring.  Look for the segment in September. The second is a ‘Buy Local’ marketing campaign that has very adequate funding. The state is buying lots of local television and radio advertising, and providing farmers with promotional price signs and posters.  This is a very exciting program, and our support and use of the material and free advertising will really help it succeed.  For promotional material and more information contact Jennifer Grahovac at 802-828-3828.
 
 

POOR RASPBERRY YEAR FOR MANY

Poor fruit set in raspberries is a common complaint across the state this year. This may be due to the temperature pattern this past winter. National Weather Service records out of Burlington show that the average minimum temperature in December was 10 degrees ABOVE normal, then the average minimum temperatures in January, February, March and April were 6 degrees, 4 degrees, 2 degrees and 2 degrees  BELOW normal. Not just extreme cold but fluctuation in winter temperature can cause plant injury, as tissues fail to harden off adequately, or, in the
case of late spring, tissues can break dormancy and then get whacked by a frost or chilling temperature. Of course, cold rainy weather during pollination that limits insect activity can also reduce fruit set. And, virus infection can reduce yield and berry quality

CORN PEST UPDATE (from UMass and UMaine Extension)

Corn earworm (CEW) moths numbers have reached high levels in many parts of the region. European corn borer (ECB) flight counts are up and new hatch can be expected soon. Fall armyworm (FAW) infestations in whorl and pre-tassel corn are above threshold in many fields. Sap beetles and aphids are showing up. Frequent rain can reduce the residual control from sprays. This situation requires close attention to your fields, spray equipment, spray materials, and timing.

Before silk, scout fields for ECB and FAW, starting in the whorl stage. At whorl stage, you’ll probably see FAW damage only (ragged holes, lots of frass). In emerging tassels, you’ll find both small ECB and FAW larvae. If FAW damage is found on more than15% off plants then direct sprays into the whorl. Otherwise, spray as the green tassel emerges from the whorl if damage to tassels is above15%. It’s best to clean up FAW before ears develop because once they get into the ear you won’t reach them; effective insecticides include Avaunt, Lannate, Spintor or Entrust (organic), and Warrior.

In silking corn you won’t get good control unless the ears receive thorough coverage. Best coverage comes from a boom with one nozzle over the row, and double drops between rows (2 nozzles on each drop, about 24 inches apart, directed at the ears from above and below).  These soak the ear zone on both sides of the plant better than sprays from above. Use higher water volume for single drops (36 to 54 gal/acre) and for double drops (60 to 90 gal/acre) than you might use for a simple boom sprayer. If you are using a mist blower, spray when there is virtually NO air movement (you might need headlights) so that the cloud of mist will settle down between the rows. Don’t try to blow through the corn because the rows effectively block the spray. Instead, direct the mist over the top and down. Trying to spray further in than 6 or 7 rows from the side of a block usually means poor control in the center, so it’s best to plant late corn blocks no more than 14 rows wide. Clip some water-sensitive cards to corn silks to test your coverage.

Ear-directed sprays should begin when 10 to 30% of ears show silk because fresh silk is most attractive to egg-laying CEW moths. New silks usually emerge for 4 to 5 days, more in uneven stands. CEW and ECB caterpillars can continue to hatch and enter ears during the 3 weeks from first silk to harvest, but the first week of silk is most critical because there is a combination of high egg deposition and new silk growth.

A spray applied 5 to 6 hours before rain, so it has time to dry, it more likely to stick. If less than that, repeat the application when corn is dry, if label allows.

Corn leaf aphids can infest tassels, stalks, and husks of corn plants in fields that have not recently been sprayed for other pests. Aphid waste (honeydew)  promotes sooty mold fungus. If sooty mold grows on the husks it can reduce the value of the corn. Sprays applied for corn earworm will usually control aphids, too. A spray for aphids would only be recommended if sooty mold is becoming a problem.

FRUIT WORKSHOPS IN NH AUGUST 22

The North American Fruit Explorers will meet at the Holiday Inn, Manchester NH on Friday morning Aug. 22, followed by orchard tours Friday afternoon and Saturday. Workshop speakers  are top notch and topics include: Apple and Pear Rootstocks, Stone Fruit Rootstocks, History of Apples in New England, Storing and Processing Fruit, Origin of the Highbush Blueberry,  Uncommon Fruits, Espalier Pruning, Holistic Disease Management of Fruit Trees, Medicinal Uses of Fruit Plants, Breeding Grapes for Cold Climates, Strawberry Plasticulture for the Northern Grower and Growing Nuts in the North. For information contact Victoria Caron at vicaron@gis.net or go to www.nafex.org/

TWILIGHT MEETING AT EDGEWATER FARM

At 5 pm Tuesday August 19 there will be a fruit and vegetable twilight meeting at Pooh and Anne Sprague’s. Topics include weed, disease and insect management. UNH and UVM Extension personnel will be in attendance. 3 pesticide applicator credits will be offered. To get there from VT take exit 20 off I-89, just across the river in NH,  go south 4 miles on Route 12A. Turn right on River Rd. at the River Bend vet clinic, the farm is 1/8 mile on left. For more info contact Set Wilner at UNH Extension (603) 863-9200.

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