Vermont Vegetable and Berry News – July 1, 2005
Compiled by Vern Grubinger
University of Vermont Extension
(802) 257-7967 ext.13


(S. Royalton) Things are starting to take off. I put in corn (untreated seed) on those two hot days in early May and most of it germinated despite cool weather that followed, which backs up what I've heard about the temperature of the water that first reaches the seed being critical to germination.  Of course it didn't grow much after that. I should be picking green-sprouted new spuds this week, which is a week later then last year.

(Jericho) The cool wet weather earlier seems to have set back insect pests, particularly Colorado potato beetle. However, every year we see more rose chafers. They do significant damage to perennial flowers, some annuals, and basil. Weeds have become a problem, and we will till under some low value crops that aren't worth the trouble of weeding. We’re picking greenhouse tomatoes and cukes. In the field we’re picking sugar snap peas and squash. I'm glad I left the clear tunnels on my melons, as it went down to 40 degrees the other night.

(Starksboro) Too cold. Too dry. Too hot. Too wet. Just right. Strawberries look promising. Lettuce and spinach are a mess at a time when they're usually at their best.

(Plainfield)  My counts of tarnished plant bug (TPB) in strawberries are between .5 and 1.0 per cluster, with bloom over and most of the fruit well set. I will lose some of my late berries, but overall there should be relatively few cat-faced fruit. I sprayed Naturalis-O (Beauvaria bassiana fungus) with MPede (insecticidal soap), and Azadirect (neem) every 5 days for 5 sprays total. I have found dead TPB nymphs in my counts. Still, this is suppression not control. I have had no previous success against TPB with rotenone/pyrethrum products. Pyganic (pyrethrum) plus Entrust (spinosad), with Azadirect, has controlled both flea beetles and striped cucumber beetles. Spray early and often. Weed control looks good. We’re using all types of cultivation plus hiring hand weeders. Hope it all pays off. We plan to be picking strawberries by the 4th of July but nothing red yet. Shipping some leafy greens. Still seeding away. One more acre to plant.

(W. Rutland) It was 40 degrees the other morning. Really makes one think about cutting extra wood and not weeding the fields. Flea beetles and squash bugs were here, but not anymore. No other insects to note at this time. However, it appears there has been an unwanted 4-legged forager for which I tolerate no threshold. A single surgical strike was the remedy to that problem, and it only costs 11 cents.

(Stamford VT) Pole beans are all planted. Most are up and doing well even with all the cool wet weather. Winter squashes are all in. Tomatoes and cucumber transplants need some heat and a little TLC after the rain. Set back at least a full week on all the planting. Glads went in late but came up quick. One deer browsed thru and chomped off the tops on about 50 of the sunflowers. A few cucumber beetles.

(adapted from Quebec web site by Rebecca Nixon, Old Athens Farm)

During hot weather remember to irrigate properly. The main cooling mechanism for tomato plants is evapo-transpiration. Keep your humidity at 70%.  If it is not too hot you can do this by venting less. The plants will keep the temperature down 2 to 3 degrees in your greenhouse through evapo-transpiration. If the temperature hits 80 degrees F, you will have to compromise with the humidity and ventilate. It can't get too hot.  If you have good vigorous plants the fruit should set nicely with the sun and heat. The trusses should be short, strong, and grow from the stem at a 60 to 90 degree angle. Weak plants will make long thin (vegetative) trusses. Your fruit quality will suffer on these trusses.  Unfortunately the cloudy May helped give us a lot of these trusses.

In hot weather you can keep the greenhouse opened up 24 hours a day but with stagnant air the plants will not recuperate overnight. The temperature can go as low as 53 degrees F. If you are able, start heating at 4am to avoid condensation. Don't let the sun warm up your greenhouse since you want an ‘active’ environment as soon as sunlight is available.

Blotchy fruit and uneven ripening can be caused by the following: Lack of potassium at the fruit caused by plants that are not transpiring enough; a cold climate in the greenhouse when the fruit are ripening; vegetative plants; too large a fruit load; low light.

(adapted from John Mishanec, Cornell Extension)

Earliest corn may soon be in late whorl stage, and that is when you should start scouting for European corn borer. Examine at least 5 locations in the field, looking into the center of the whorl for tiny windows where larvae have chewed but not gone through the leaf. When the larvae get bigger, they begin to chew holes and you will see frass (sawdust) on the leaf. If more than 5% of plants show damage then you should plan to control the larvae once the plants are tasseling. The best time to apply a control is when the individual tassels are beginning to separate but have not completely spread out. At that stage the larvae will be exposed while feeding on the tassel flowers so applying an insecticide will give you effective control. Make your first application when 40% of the field is in this stage and then wait another 4 to 6 days for the rest of the field to come into tassel for another application. This will ensure you make a control application at the right time on all the plants. Applying a spray earlier (in the whorl stage) will not give good results because larvae are protected deep in the plant. Applying a spray after tasseling also does not work as the larvae drop down to the ear and again are inside the plant and protected. Conventional growers can use a variety of products; check the New England Vegetable Management Guide. For organic growers, Entrust works well.

Tuesday, August 9th at the Intervale Community Farm, Burlington

This day-long workshop will provide beginning growers with practical tips and techniques for growing healthy horticultural and agronomic crops. Topics to be covered include: management techniques for healthy soils, and identification and management of insects, diseases and weeds. The day will also include time for discussion on marketing, business planning, and finding farmland. Stay tuned for details.

Mention of pesticide names is for your information only, no endorsement in intended nor is discrimination against products not mentioned. Always read and follow the label.