July 1, 1998
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967 verng@sover.net

REPORTS FROM THE FIELD

A week ago our pastured poultry was in 4" of water, but we haven't received any rain since. Have been cultivating for 3 days and fields are clean. Cucurbits under floating row cover look excellent. Winter squash only 50% germinated due to cold temps and rain, replanted this week. Lots of cuke beetles around, so far doing nothing about them. Potatoes beginning to blossom and no Colorado potato beetle (CPB) yet. We expect hatch next week. Corn is knee high and weed free. Flea beetles completely controlled with row covers. Cutworm has subsided, broccoli now a week from first harvest. A huge strawberry crop, not rotting, but not very tasty due to all the water. Peas delayed by early heat finally bearing now, picking snow peas, sugar snaps next week. Greens all excellent quality. (Amherst MA)

No sign of cucumber beetles so far. Very few flea beetles as well. Plenty of bottom rot or some kind of rot on the lettuce. May have to plow in quite a lot. A few potato beetles and larvae starting to appear. (Charlotte)

That rainy and warm week June 13-18 had a dramatic effect my Tom-Cast calculations for early blight disease severity values (DSV). I reached 35 DSV (the threshold for the first early blight spray) on June 19. Considerable CPB hatching in fields near where susceptible crops were last year, but no hatching of CPB in fields far from last year's crops - a strong case for rotation. I have heard rumors of potato leaf hoppers in southern Addison County. (Starksboro)

Field Crops (Addison, Chittenden, Rutland and Washington Counties): fretting over drought gave way to fretting over how long crops can tread water. As long as rainfall is periodic instead of constant or not at all, we're off to a great season. Well-drained fields have the best looking corn and new seedings that I've seen in a number of years. Rain helped to germinate seed on fields that had an erratic start. Even most poorly drained fields only have small areas that were lost to standing water (so far). Corn PSNT levels have been about "average" rain does not appear to have severely lowered N levels. Weed control by herbicides is mostly good; cultivation is difficult while soil is soggy. Hay regrowth good where nutrient need has been supplied by manure, fertilizer or compost. Apply nutrients immediately after harvest and just before rain (not downpour) for best results. Potato leafhopper is here, but low levels so far at least on the few fields I've checked. (S. Hawkins)

Slugs currently ripping into unprotected ginseng and strawberry plantings (Middlebury)

The weather royally sucked for harvesting early strawberries. Pickers chose not to come out between the torrential thundershowers. The continually sodden week was perfect for botrytis, turning king berries into monster mouseberries as well as bottom rotting our peas, which we have been picking, and lettuce. Weather totally prevented any cultivation or spraying, making it a pretty grim scenario here. (E. Hartland)

Rain (4" last week) has been good for us (on sandy soil), but cultivating and spraying potatoes with B.t. have been delayed. Many CPB on potatoes. Huge year for striped cuke beetles, they're on non?target plants too. May be forced to use rotenone for first time in 12 years. (Townshend)

Melons that are on black plastic and under row cover started flowering 2 weeks ahead of least year; was worried because plants were so small but left the covers on a little longer even though flowering and they grew a lot last week (S. Royalton)

UMASS PEST MESSAGES AVAILABLE
Ruth Hazzard and Sonia Schloemann do a fantastic job of keeping vegetable and berry growers, respectively, up to speed on the latest pest issues, and you can receive their weekly electronic pest messages for free! Ask to be added to the distribution list by e-mailing your name, address and phone to rhazzard@umext.umass.edu for vegetables and sgs@umext.umass.edu for berries. The berry weekly e-mail message will only last another 3 weeks. For $30/year you can subscribe to the UMass small fruit newsletter (hardcopy only, back issues will be sent to late subscribers).

SCOUTING FOR POTATO LEAFHOPPER
Don't get surprised by PLH this year...scout for them! They've already arrived in orchards in New York and New Hampshire, and were found in beans in Long Island 2 weeks earlier than last year. In case you forgot, these wedge-shaped insects feed on sap from the undersides of leaves causing them to distort and turn yellow and eventually crispy. Adults migrate in on winds from the south, then lay eggs which hatch in 6 to 9 days. Use a sweep net if you have one, or brush plants with your hand to cause the whitish-pale green adults to fly off. The lime-green nymphs do not fly, and become winged adults about 3 weeks after hatching. They're about a sixteenth of an inch long and tend to hide in leaf axils so examine plants carefully. Look in several different sections of a field. Start scouting with alfalfa, potato, beans, but PLH has been found on 200 different plant species. Thresholds and control options vary among crops. Check your management guides or give me a holler.

AVOIDING SCAB ON POTATO
The common scab organism lives on decaying organic matter in the soil, and causes blemishes when it infects fleshy root crops like potato, beet and carrot. Infection usually occurs early in the season, promoted by dry soil, undecomposed manure, and pH between 5.2 and 7. Prevention includes rotating out of susceptible crops for 2 years and irrigating to assure abundant soil moisture during tuber initiation, which coincides with the appearance of flowers in most cultivars. Scab-resistant potato cultivars include: Norchip, Norland, Pike, Salem and Superior.

GREENHOUSE VEGETABLE ACREAGE
According to a report in Tomato magazine, the US, Canada and Mexico each have between 650 and 850 acres of greenhouse vegetable production. Compare that to Spain with 30,000 acres, Holland with over 11,000 and England with 3,000 acres.

KEEP BERRIES FRESH AFTER HARVEST
Dr. Dave Handley reminds you to harvest strawberries early in the morning, and keep fruit out of direct sunlight. Place fruit that won't be sold right away into refrigerated storage, 32 degrees and 95%RH is ideal. Make sure cold air can circulate around flats or boxes of fruit, use fans if necessary to keep cold air moving.