June 15, 2000
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967

(Williston)  Finally able to harrow the field for Memorial Day. Good thing we planted all the squash and pumpkins in the greenhouse to try and keep ahead of Mother Nature!  She did get even though...cucumber beetles arrived before dusk. Just hoping the first spray gives the plants enough time to leaf out so they aren't a problem anymore. On the bright side, our apple crop looks good, regardless of the cloudy spring,.not much scab or disease and good pollination.

(W. Rutland) Starting to close up the greenhouses. Field work is progressing well now that the land is dried out. Early transplants are coming back from their soggy start. Insect damage is small but to many cotton tails eating my beans.

(Shaftsbury) Great year for row covers, they have made a major difference. Verticillium identified in 3-year old tomato greenhouse. Flea beetles not to bad this year. Great strawberry bloom. Early varieties are done flowering, later ones are close, and NO TPB... yet; perhaps a cold spring has some advantages.

(Marlboro) Raspberry and blueberry plants still looking good- they must like the cool  weather- good blossom but only a few bumble bees sighted to date. We did not rent bees this year so will have to wait and see about pollination....

(S. Royalton) The insect that is causing the most problems is flea beetles, we tried spraying transplants with garlic the day before setting them out with garlic and that slowed them down but we will have to resort to rotenone after we take off row covers. Appears to be about a 50% loss of garlic due to winterkill with all the freezing and thawing and ice, but the greenhouse tomatoes look the best we've ever had. Crops in general appear to be growing slowly then jump when we get a day or two of warmer weather and sun.

(Starksboro) Most of the fields have dried up adequately now, and we're pretty much on schedule. Tomatoes went out in the last days of May and I started calculating TomCast Disease Severity Values. They haven't been adding up very fast because it's either been warm and dry
or cool and wet, neither of which are conducive to the development of Early Blight. Have a few adult CPB in the potatoes but they had to cross the creek to get from last year's field where they wintered to this year's field and not many have figured that out. So, I've got a good head start.

(Hadley MA) On Friday evening June 5, a hail storm blew through the Connecticut Valley at high velocity. The storm raged for about 20 minutes with high winds, heavy  rains and large hail. All of our Spring crops were shredded or buried in mud. We lost peas, strawberries, lettuce, tomatoes, melons, etc. However, I haven't seen a flea beetle yet, and I don't dare complain about the few cutworms I've seen. We have postponed our first CSA distribution for a month. Replanting and reseeding has begun in earnest. We are in high hopes of patching together this season. We will miss those strawberries and peas this year.

(Argyle NY) After more than a week of dry weather, most of our fields were dry enough to get a seeding in, plant some potatoes, and lots of transplants (lettuce, spinach, onions, leeks, celery, parsley, peppers, cabbage, and eggplant). The tomatoes are still waiting since it's pouring rain again today.  It's been a much more challenging spring than in past years and even with lights on the tractors, the work isn't on schedule!  Both the annual bed and matted row strawberries were ready for their initial picking on June 2. Some crops like beets, Swiss chard, and turnips will be late for harvest by 2 to 3 weeks due to seeding challenges in April. The farmers' markets are real strong and customers are already asking for sweet corn and tomatoes!  We tell them the peas are flowering!  We finally found a few part-time college workers, so the work crew looks good for the season. Insects have been mostly non-existent except some flea beetles and slugs (we'll get the ducks working again).

(Montreal) It's been a long wet spring, with temperatures several degrees below normal. Nonetheless, we are finding that germination of carrots, spinach and radishes is much better than during last years drought. The sugar snap peas need to be trellised.  Everything is running about 3 weeks later than normal. Put out our summer squashes June 5. Fingerling potatoes got into the ground late and still aren't up yet. Anticipating our first CSA baskets for June 22.

(Adapted from T. Morris and R. Ashley, Univ. of Connecticut IPM Program)

Growers often apply some extra N fertilizer to vegetable crops for "insurance" to be sure that the crop will not be deficient in N, especially towards the end of the growing season. Applying more N than is necessary to sweet corn does not reduce yield, but it does reduce profit, and it poses a risk to water quality. Application of "insurance N" to other vegetable crops, such as pumpkins and tomatoes can reduce yields as well. The pre-sidedress soil nitrate test (PSNT) is a tool for determining how much N fertilizer is actually needed. In corn, the test involves collecting a composite soil sample by taking cores 12 inches deep from between the rows, when plants are 6 to 12 inches tall. The sample is then air-dried and sent to the soil test lab. If the results show soil nitrate-N concentration is greater than 25 parts per million (ppm), no fertilizer N is needed; if the concentration is less than 25 ppm, topdressed N fertilizer is recommended based on how much nitrate-N is detected.

A recent study was to conducted to determine if the PSNT is useful for estimating the N topdress requirement for pumpkins. Thirteen experiments were conducted in CT, NY and NH. The N rates were 0, 30, 60, 90, 120, and 150 lbs/acre. The N fertilizer was applied before planting. Pumpkins were direct seeded in the first half of June. Plants were thinned to one plant/hill about 2 weeks after seeding. Weeds were controlled using the stale seedbed method or Curbit herbicide, and were then mechanically cultivated, and hand-hoed. Soil samples were collected from the top 12 inches of soil about a week before the vines began to run. The soil samples were spread to air-dry within a few hours of collection.

The yield response to N for the 13 experiments was a C-shaped curve. The average yield for the experiments reached a maximum of 15.9 tons/acre at the 90 lb/acre treatment, which was 4.2 tons  greater than the zero N treatment. The two highest N treatments, 120 and 150 lbs N/acre, yielded significantly less than with 90 lb/acre, suggesting that 90 lbs N/acre should be the recommended rate of N for pumpkins, not 130 lbs N/acre as listed in the New England Vegetable Management Guide.

Although this research is still preliminary and more data will be collected this year, you may want to try using the PSNT in your pumpkin fields. Based on the work at UConn, if the results are 0-10 ppm, then 50-90 lb N/acre is recommended; at 10-20 ppm, apply 30-60 lb N/acre, at 20-30 ppm, apply no more than 40 lb N/acre. If more than 30 ppm nitrate-N is detected, a response to additional N fertilization will be highly unlikely.

PSNT samples should be clearly labeled and mailed promptly to: Ag Testing Lab, Hills Building, Burlington VT 05405-0082, along with a check payable to UVM for $6 per sample. Note: special sample bags have been developed by UConn that avoid the need to air dry the samples, call me if you'd like to use them.

(Adapted from UVM entomology fact sheet by G. Neilson)
Several growers are finding extensive seed corn maggot damage, which is often greater in cold, wet weather and when the seed is deeply planted. The maggot injures sprouting corn, beans and peas as well as cabbage, turnip, radish, onion, beet, spinach, and potatoes, especially when conditions contribute to slow germination and emergence. The seed corn maggot passes the winter in the soil of infested fields in the maggot stage inside the last larval skin--a dark brown, capsule-like puparia about 2 inch long. Occasionally, they also winter as maggots in manure or about the roots of clovers. The first-generation adult flies emerge in early spring. These flies are gray-brown-greenish in color and 1/5 inch long. They deposit eggs in the soil where organic matter (such as fresh manure) is decaying, or on the seed or young plants. The hatching maggots make their way to sprouting seeds which they bore into, feed on, and destroy. The eggs hatch at temperatures as low as 50 degrees F. Larval and pupal development may continue at temperatures above the mid-50s. Full-grown maggots are yellowish-white, about 1/4 inch long, sharply pointed at head end and legless. Pupation takes about 2 weeks. The life cycle can be completed in 3 weeks, and there are probably 3 generations per year in Vermont. It is the first that does the severe damage. The second and third generation appear in mid- and late summer. Because the weather and seed corn maggot populations are very variable, take precautions every year to keep damage from this insect to a minimum. Otherwise, the seed corn maggot will probably not be detected until seeds and seedlings are lost. Then it is too late for effective control, and the field must either be replanted or left as a poor stand. Control consists of prevention. Plant only after the ground is warm enough for rapid germination and growth. Plow heavily manured or cover-cropped land early the previous fall, so it will be less attractive to the egg laying flies the following spring. By thoroughly mixing in organic matter to prepare the surface layers of the soil, you'll get more rapid germination. That, in addition to shallow planting, will reduce the damage, because the insect is attracted by humus and moisture. Delay planting until the first generation is pupating (probably early June). Reduce use of organic fertilizer in the seeded row, whenever possible. Reset or replant heavily damaged fields to get an adequate stand.  Seed may be protected to some extent with an insecticide seed treatment.

BotaniGard has again caused injury on tomato plants in the greenhouse. This is a bio-insecticide containing the fungus Beauvaria bassiania. For the past 2 years several growers have reported that tomato plants sprayed with BotaniGard ES have developed dramatic edema and downward curling of the leaves. Severe injury has been reported with the ES formulation although slight injury has also been reported with the WP.  BotaniGard is an effective product, labeled for many crops, and is widely used in greenhouses; however, it should be applied to tomatoes in the greenhouse with caution.

MEETING REMINDERS (Contact Vern for directions or more info)
June 13 - Nesenkeag Cooperative Farm, Litchfield NH. Production equipment, techniques, and  markets for organic crops. Extension presentations. 5:45 pm. Free.

June 24 - Workshop with Trauger Groh at High Mowings Organic Seeds in North Wolcott.  "The Future of Agriculture". $40 pre-registration. Tom Stearns, 888-2480

June 28  - Intervale Community Farm, "Large-Scale CSA". Burlington. 3-5 pm. Free.