June 15, 1998
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967 verng@sover.net

REPORTS FROM THE FIELD

Striped cucumber beetles found in potatoes, but none as yet in any squash. Colorado potato beetles have laid their first eggs and I'm keeping a close eye so I catch them at 30% hatch, which is the perfect time for the first spray of BT. Usually that happens about June 20?25. I've done a PSNT (pre-sidedress nitrate test) for my first planting of sweet corn. Others might think about this - sample soil when plants reach 8 to 10 inches tall (see article below!). Strawberry crop looks excellent. I'm scouting for cabbage caterpillars. I usually don't see any until the first week in July, but with the warm weather they might start early. I've been using the Tom?Cast program for predicating tomato disease development. I make the calculations long hand. So far the Disease Severity Value (DSV) has been fairly low due to the cool weather since June 1 so I expect to reach the threshold of 35 DSV for the first spray around the normal date, which is sometime in the first week in July. (Starksboro)

The cold week of June 1 was spent alternately irrigating for frost or counteracting the action of the incessant drying winds that make our rowcovers dance merrily into the next township. About a week or less from picking strawberries on bare ground. Planting last sweet corn and weeding furiously. I'll bet a dry summer ups our labor bill 30+% from just the effort put into irrigating. (E. Hartland)

Cold windy conditions have slowed things and caused some stress to pepper and tomato transplants. Early strawberries are in, some signs of gray mold. We keep out of the field when foliage is wet. Peas are looking fine and our sugar annes are nearly ready for harvest. All brassicas and greens and summer squash are under row covers. Nice cultivating weather, weeds are pretty much under control with mechanical cultivation. We've begun to remove garlic flowers and are distributing them to our CSA shareholders. (Hadley MA)

Field Crops (Addison, Chittenden, Rutland, and Washington Counties): Corn is quite pale in the whorl nearly everywhere? not a nutrient problem or unhealthy plants. Corn on clay soil by the lake is suffering? very little rain, so erratic germination. Worst where planting was shallow, or in a poor seedbed. Weeds also not germinating, but I suspect with rain they will and by that time any herbicides used will be fairly ineffective. Very little insect damage ? finding the occasional cutworm, thrips and potato stem borer. Hay crop has been better than the last few years. Alfalfa weevil prevalent before 1st cut taken, not seen any in regrowth, but monitor for chewed "lacy" leaves and a small green caterpillar. (S. Hawkins)

Imported cabbageworm larvae, average of one per plant, on cabbage just starting to cup. Time to apply BT once the wind dies down. First plantings of wholesale lettuce being harvested - good yields, good prices. (Westminster)

Alfalfa mosaic virus confirmed on a few plants in a tomato greenhouse surrounded by (you guessed it) an alfalfa field. Symptoms were stunting, yellow foliage, leaflets curled downward. Transmitted by aphids, this virus can also affect potato, celery, lettuce, bean, pepper, red and white clover. According to the Compendium of Tomato Diseases, secondary spread from these infected plants to neighbors is rare. Planting away from alfalfa usually avoids the problem. How far? Several hundred yards.....or as far as practical. (St. Albans)

Two-spotted spider mites in strawberries at high populations (Brandon).

PSNT FOR SWEET CORN
The Pre-Sidedress N Test can help you optimize the amount of N fertilizer you sidedress your sweet corn with. By measuring the amount of nitrate-N in the soil early in the season, a prediction can be made about how much fertilizer N is required to meet the crop's needs for the rest of the season. The process is simple: when corn is 8 to 12 inches tall, collect 15 to 20 soil cores from between the rows of a single corn planting (do not mix soil from different fields). Try to go 12 inches deep. Avoid starter fertilizer bands, or areas where broadcast fertilizer or manure applications were unusually heavy or light. Mix all the cores together. Immediately take 1 cup of soil and dry at 200 degrees in the oven, or allow to air dry on a non-absorbent surface. A fan blowing on the soil will help. Once dry, place in a plastic bag and send to the UVM Ag. Testing Lab, Hills Building, Burlington VT 05405-0082 with $6 per sample, and your name, phone and mailing address. Be sure to identify the samples as sweet corn samples or you will receive field corn fertilizer recommendations. The lab will run samples within a day of getting them, so you should have your soil nitrate numbers back about a week after mailing the soil. For sweet corn, based on work done by UMass, UNH and UConn, I recommend fertilizer as follows:
PSNT Result: Sidedress N lb/acre:
0-10 ppm 130
11-20 100
21-25 50
25+ 0

WEATHER WEB SITES FOR SURFIN' GROWERS (By Fred Bacon)
http://met.www.cit.cornell.edu/cgi/fcst?vt014
This site gives the daily weather forecast for regions around the state. It also forecasts the weather for the next 5 days.

http://www.agriculturalweather.com/main1.html
This site gives a variety of weather data including 6?10 day forecasts for precipitation, and temperature. There is also a 14 day soil moisture forecast, satellite and radar images and other information.

http://bristol.wbox.noaa.gov/climatenew.html
This site collects a variety of weather data for regions around the state. Data is shown for temperature (max,min,avg), precipitation, humidity, and other information. The data is formatted and maintained on a daily, monthly and annual basis.

NEW FUNGICIDE FOR TOMATO DISEASES
Quadris Flowable Fungicide made by Zeneca Ag Products, characterized by US EPA as a "reduced-risk pesticide" is now registered in Vermont for use on field tomatoes. Trials at Cornell have shown Quadris to outperform 6 other fungicides for control of early blight (Alternaria solani), maintaining green foliage to the end of the season even under severe pressure, enhancing quantity and quality of marketable fruit. Quadris should be used prior to or at the onset of disease development, since it is a preventative fungicidie. It also appears to be effective against late blight (Phytophthera infestans). Be sure to follow the label to get best results.