VERMONT VEGETABLE AND BERRY NEWS - June 15, 2001
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967 or vernon.grubinger@uvm.edu

REPORTS FROM THE FIELD (as of June 11)

S. Royalton - Half of my first planting of corn got caught in that wet, cold period and the seed turned to field snot.  The eggplant and peppers are off to a slow start but the tomatoes look good.  When planting the watermelon I noted a few diseased ones and gave them the old heave ho.  It was too late however, within 6 days of transplanting the whole lot of them were dead.  Maybe it's
a blessing as they are a pain to store and transport.

E. Hartland - We are about 10 to12 days away from strawberry  picking and u-pick (without  row covers) if we continue with  sunny weather. The berry crop looks good. Cool nights have kept things slowed down, and although things are growing, they  are doing so slowly as the nights are still in the 40's. Anything without row covers isnít making the headway it normally should this time of year so things are behind. It is a screwy year, again. Thank goodness for bedding  plants.

Starksboro - The weather overall has been pretty good. We've had a decent mix of rain and sun. We're coming into the thick of bug wars. Lots of striped cucumber beetles. To my surprise they seem to like tomatillos more than anything else. Rather like Colorado potato beetles and eggplant. We have 2 potato fields this year, and the smaller one closer to last year's potatoes are currently taking the brunt of the assault by the CPB. The other field is virtually free of them. Flea beetles out in full force.

Killington - Have been selling mixed greens for a week.  Row covers have slowed down flea beetle on greens. Sugar snaps are doing well and should be ready in  two weeks. Beets, string beans, and spinach coming along. Night time temperatures rising enough to put out eggplant and peppers  Meat sales of pork and chicken are helping numbers at the farm stand.

Jericho - We are getting a nice mix of weather now. A little more rain would help. Two weeks ago we had heavy rain and fifteen minutes of hail on Monday. The only damage was to our early greens which got shredded. Then we had a little snow on Wednesday and a frost on Thursday! The week of June 4 was much better and we got all of our warm weather crops in. Potatoes are looking good. Some TPB in our strawberries, but not as bad as two years ago. We started picking berries June 10. The only other serious pest so far has been flea beetle. We are picking early broccoli, Swiss chard, kale, arugula, lettuce and radish.

Argyle NY - Strawberries are coming in slow due to the cold nights;  Lettuce is enjoying this weather, but spinach is turning yellow due to excessive amounts of rain. The nice weather last week allowed us to get back on the fields for seeding, cultivating, and transplanting (and irrigating), but we're still behind schedule. Pests include slugs which flourished and reproduced last year; also cucumber beetles. Peas will be ready within a week, and potatoes are not
far away (first planting anyway; last planting isn't even in the ground!). With the snows in March, heavy rains, then a dry period, the only thing we haven't had is heat, so that's next to challenge us.  Still looking for interns to help with the fun!

W. Rutland - Problems with compost, iron deficiency?  Not me, I use Fafard mix and Scotts Testing lab to make sure those problems do not happen.  If something is missing itís as simple as mixing up the right batch of Peters, water it in and rock on. OK this a field report, Asparagus bites, the all knowing Vern thinks I need to fertilize more, who me?  Not a problem. Corn is growing well as are cut flowers, broccoli and the rest. Cukes and squash are a bit slow due to cool soil under black plastic and row cover. Root rot in beans nuked the first planting, more on the way. No report on hunting or should I say damage control, as I have been threatened with censorship.

Charlotte - All that rain finally dried out in the furrows just long enough to get the next round of things in. It's amazing how moisture stays in our clay soil. It took over a week of dry weather for the soil to work acceptably. Lettuce sales and CSA pick-ups start this week, and things look good.  Weíre ahead of last year in most every way.  No major bug problems yet, but I'm not looking forward to the arrival of the dreaded cuke and potato beetles. Any day now I'm sure. Last year the cuke beetles showed up June 6, so it's a relief to still not have them. All cucurbits are big, healthy and under row cover, but our experience is that those nasty critters can still take a toll. We dodged a bullet back on the first. The max/min thermometers said 30 degrees, but we didn't have any damage. Must have been saved by the warmth of the soil.

Plainfield - Plant sales have just been great this spring, everyone wants to get an instant garden.  Transplanted winter squash last week, very few cucumber beetles yet. Continuing with Beauvaria bassiana spray for TPB in strawberries, 10 oz per acre every 3 to 5 days. TPB counts continue to be low. Is the spray effective or are there just not that many around this year? Greenhouse tomatoes and peppers responding well to fish emulsion with Epsom salts added. Need to prepare land for later plantings, keep irrigating, and catch up on weeding. Overworked and overtired.

Nantucket MA - After a couple inches of rain in late May, we are back to extremely dry conditions. We were at the point of having to water our hairy vetch cover crop in before we could plow it down. It sucks up so much moisture anyway, and  combine that with the dry conditions and the plow was riding right out of the ground! Began harvesting lettuce June 5 along with radishes, spinach, parsley, and arugula. Strawberries are starting to turn. Have removed all plastic on early corn. First summer squashes have been freed from the row covers as well, just starting to blossom, so hopefully fruit by the next report.

CUTWORM MANAGEMENT (adapted from fact sheet by G. Neilson, UVM Extension)

There are many species of cutworms. The adults are night-flying moths which do no damage. The larvae feed on plants by chewing, and they vary as to damage done and host plants preferred. Generally they destroy more of the plant than they eat. Their numbers vary greatly from year to year. Cutworms injury is of four types. Solitary surface cutworms cut off young plants at or slightly above or below the soil line, sometimes dropping the severed plants into their burrows. Because most of the plant is not eaten, these cutworms do great damage, attacking and felling new plants nightly. The black, bronzed, clay-backed and dingy cutworms are in this group. Climbing species, the variegated and spotted cutworms, climb the stem of trees, shrubs, vines, and crops and eat the leaves, buds and fruit. Subterranean species, the pale western and glassy cutworms, remain in the soil and feed upon roots and underground parts. Army cutworms occur in great numbers, consuming plant tops and then "marching" on to other fields.

Most cutworms pass the winter as partially grown larvae. They are already large, voracious feeders when transplants and seedlings are set in the fields. Overwintering cutworms may live under trash or bark, in clumps of grass or in earthen cells in the soil. They become active and begin feeding as the weather warms in spring, remaining hidden under debris or in the soil and feeding at night. Many species continue to feed well through June, then pupate in the soil to emerge later as moths. Normally there is only one generation per year. The moths crawl from their brown pupal cases in the soil and climb up through the soil, following the tunnel made by the burrowing larva. If this tunnel is blocked, the fragile moth cannot escape the soil. The moths mate and lay eggs in late summer, beginning the next generation. The moths often seek out grassy or weedy areas to lay their eggs, which are usually deposited on plant stems or in the soil. One female may lay hundreds of eggs. The hatching larvae feed until cold weather and then hide for the winter in a sheltered, dry place.

Cultural practices may offer some degree of cutworm control: Plow and fallow fields in mid- to late summer to prevent the laying of eggs. Plow in the fall to expose the larvae or deeply bury the pupae. Cultivate fields in the spring after vegetation has appeared and grown a few inches, then delay seeding to starve the cutworms. Plan rotations to avoid row crops following a grassy sod. Plow sod fields in late summer or early fall the year before planting. Cultivate young crops frequently to injure and expose hiding cutworms to predators. Insecticide treatments can be directed toward the soil surface on the plants; pyrethroids are labeled for most vegetable crops (see the New England Vegetable Management Guide). Granular insecticide treatments, applied to the seed or to developing seedlings, are of little, if any, value in controlling cutworms.

Dr. Eric Sideman from Maine reports that organic growers have been successfully using a Bt  bait. They mix a concentrated Bt solution with bran and molasses and place along the rows of crops. One grower has had good luck with making patties of the material and placing them out.

'ZEA-LATER' AVAILABLE FOR CORN EARWORM CONTROL
(adapted from article by Ruth Hazzard, UMass Extension)

Corn earworm moths arrive on storm fronts in mid- to late-summer, ready to lay their single, globe-shaped white eggs on corn silks, preferring fresh silk over dried silk. Newly hatched caterpillars move rapidly into the silk channel, enclosed by the top of the husk. They feed very little on the exposed silk, which explains why sprays of Bt are not very effective against this pest. Corn earworm has been a major obstacle to production of organic sweet corn, and conventional control of this pest relies on repeated applications of synthetic insecticides. A new method of control has been developed that uses small quantities of vegetable oil mixed with the biological insecticide Bt (Bacillus thuringiensis). The Zea-Later oil applicator, now commercially available, makes this method physically and economically feasible. Research results over several years have shown very good control.

The Zea-Later is a hand-held applicator connected by a plastic tube to a 2-liter waist-belt tank. The applicator Ďguní has a shell of strong molded plastic, with an internal pumping mechanism. The molded handle fits easily in the hand, and each pull of  the ""trigger" releases a 0.5 ml dose of oil. Growers and workers who use it are surprised at the lack of hand fatigue, even with several hours of use. The pointed tip is placed on the hollow at the center of the silk ear or pushed slightly into the silk channel, leaving the oil where gravity will pull it all the way into the silk channel. It works best to walk down each row, treating the top ear of each corn plant. One tankful treats about 1/4 acre. Soapy water is used for cleanup.

In the field, corn silks grow to their full length in about 2 days. The best time to apply the oil and Bt mixture is 4 to 6 days after silk growth starts or 2 to 4 days after the silk is full-grown. At this time, most of the pollination has taken place, and the exposed silks are wilting and beginning to turn brown. Earlier applications do not appear to give better control, but result in a higher rate of poor tip fill. Oil applied later than 6 days after silk initiation can result in poorer control. One application to each block of corn is adequate. Itís important to know when corn earworm is active in your area, since its activity may be unpredictable, especially in northern regions, where migratory flights arrive suddenly. Flights can be monitored with the Scentry Heliothis net trap, baited with Hercon  lure tapes for corn earworm, placed at about ear height in freshly silking corn. Trap captures of two moths per week, or more, indicate damaging numbers.

Corn or soy vegetable oils are exempt from both federal pesticide labeling and residue tolerance requirement, so they can legally be used on sweet corn. Vegetable oil products with a pesticide label and organic certification include Golden Natural Spray Oil (Stoller Enterprises, Inc), which is soybean oil with an emulsifier. For clarification of any product''s regulatory status, contact your stateís agriculture department. Mixing Bt with the oil improves control by about 15% over oil used alone. Bt products labeled for sweet corn come in liquid or dry formulations; in either case, it is important to achieve a stable, fine suspension of the Bt crystals in the oil. For dry products, this requires an emulsifier in the oil. Most liquid products will form a suspension, but should be tested to be sure. Regular agitation may be needed.

At first glance, it hardly seems possible that treating every ear could be cost-effective. In fact, the cost is in the same range as conventional methods. The one-time oil treatment usually takes 8 to10 hours per acre so labor cost ranges from $60 to 80 per acre. Materials include about 2 gallons of oil (at $6 per gallon) and 1 pint Bt ($5 to 7) per acre. For many retail growers, each successive block is typically less than an acre, so it can be treated in one day or less. This can be done in windy conditions, on two successive days if necessary, and does not have to be re-applied after a rainstorm. Some growers would prefer to use a crew of two or three because, as with many repetitive jobs on the farm, it is more pleasant to work in a group and get the job done faster. The Zea-Later is available for $214 from Johnnyís Selected Seeds (207) 437-4395 or commercial@johnnyseeds.com

(Mention of brand-name products is for information purposes only, no endorsement is intended)