VERMONT VEGETABLE AND BERRY NEWS - July 1, 2001
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967 or vernon.grubinger@uvm.edu

REPORTS FROM THE FIELD

(Burlington) It’s a strange season when we harvest zucchini before strawberries or peas. My first peas were flooded by the warm weather snow melt in late April and I got zucchini in just before the couple of warm dry weeks in May. Black plastic and row cover helped get them through the cool weather and to my surprise I had harvestable zukes by June 13. Flea beetles are ferocious in Brassica transplants. Lots of leaf miner this year.

(Starksboro) We're in the thick of Colorado Potato Beetle (CPB) season now. I read a study about using straw mulch as a deterrent to CPB that said it was contact of the straw with the plant stems that made the difference. This year I  mulched my eggplants with straw. They should be covered with CPB by now but there are virtually none. I have just started seeing some potato leafhoppers (PLH). They probably blew in about June19. I have gotten into the habit of checking for PLH shortly after we get a strong south wind.

(W. Arlington) We have begun to pick peas and will have broccoli ready soon. Our major pest is the cucumber beetle, I've seen only a handful of CPB. We were late getting our potatoes in, so perhaps we missed the first generation. As always we are fighting the weeds. I've got to get back to work, the old candle is burning. My body is too old for this.

(W. Rutland)  I hate heat but the corn loves it, just enough rain so everything is growing well.  Perennial cut flowers are starting to be sold except for the ones deer USED to eat. One acre of corn rotted so that will be the last place I plant. Venison, it’s dinner tonight.

(Plainfield) Picking strawberries as of June 22, nice quality to start but 30% of the late berries will be TPB damaged. Winter squash looks great, cucumber beetles killed off with one dusting of 5% rotenone. Lettuce maturing nicely, marketing a challenge. Only row covers will keep our crows away from germinating corn. Flea beetles are bad on Brassica seedlings, I hope they will outgrow the damage. Greenhouse peppers and tomatoes setting fruit nicely.

(E. Hartland) Busy shifting from greenhouses to strawberries and early vegetables. A late start for  berries, I think because of a very dry early spring, the crop looks good but will look better if we can get it harvested and get the money in the bank. What we don’t need is any more hailstorms. Bugs? We’ve got hoppers, cukes beetles and adult CPB. We toasted CPBs and usually if we get the adults we don’t have to deal with them again. The Heliothis traps are empty of corn pests. The warm muggy weather has really pushed the crabgrass and lambs quarters and we are struggling to deal with them as we missed a couple of ‘timely cultivations’. We just put this year’s strawberries in. A mid -June planting of dormant plants at 52 by 16 inch spacing establishes a really nice plant density for first year matted rows and saves at least two cultivations and hoeings.

(Winchester NH) These may be the best transplanting conditions I've seen in 25 years - an inch of rain, a couple sunny days, an inch of rain, a couple of sunny days, etc. I have replanted a third of the peppers due to cutworm damage. The kaolin clay spray on the Damson plum trees did a remarkable job of repelling plum curculio. Damage is 10 to 15% and we typically see damage of 80% in our organic orchard and some old apple trees in a nearby meadow are totally riddled with feeding and egg-laying damage. Strawberries are coming along very well since we've been able to keep them cleanly picked between the rain showers. Garlic looks enormous this year.

(Little Compton RI) Southeast Rhode Island has had over 12 inches of rain since May 1. That would normally be good news if it had not come down in torrents of 2 to 4 inches just before we were ready to plant a field or cultivate young sweet corn. We have a saying down here "A dry year will scare you to death but a wet year will kill you!". The jury is still out. Flea beetles were vicious in May but oddly enough cucumber beetle has been light so far. A bright spot is that our peaches made it through the bad frost in May and are looking very good. Started a CSA this year and am delivering it to Providence. City folks are a wonderful audience for fresh produce and surprisingly quite sympathetic to our plight.

(Montreal PQ) We've bounced from extreme heat to extreme rain in the past week. Makes things grow fast. Our first CSA this week. Kohlrabi, peas, shunkyo radishes are ready as well as early Savoy cabbage and  garlic flowers. B.t. has quelched the cabbage worms but an early infestation of cabbage root maggot nixed about 15% of the cabbages. First potato beetle larva hatched on the 24th and immediately gave them a dose of B.t. For some reason there are far fewer cucumber beetles this year. Quite a few cutworms this year, busy lopping off bean and soybean shoots. Our biggest pest problem is mice eating summer squash and cucumber seeds in the greenhouse.

(Amherst MA) Growing conditions have been good the past couple of weeks. Harvesting now, lettuce and greens looking prime, early zucchini coming in, broccoli starting,  beets, scallions, chard, and cabbage on the near  horizon. Flea beetles are there but floating row covers control them. CPB not a factor yet since potatoes were rotated into a field over 1 mile away. Leafhoppers out in force, as are cuke beetles. After a really lousy spring, the early summer is looking quite promising: tomatoes, eggplant, peppers, corn, squash all growing like champs.

TOMATO RINGSPOT VIRUS IN BLUEBERRY
(from Scott Pfister, Plant Pathologist, VT Dept. Agriculture)

Blueberry plants from Vermont have tested positive for Tomato Ringspot Virus (TmRSV). This is the first report of this blueberry disease occurring in Vermont. The occurrence and intensity of the disease differs among cultivars. Young leaves may be mottled, strap-shaped, or otherwise deformed. Brown flecks may occur on infected stems and defoliation is common. Death of the plant will occur after several years. Symptoms may take several years to develop once a plant becomes infected. TmRSV is transmitted in the soil by the dagger nematode. It is retained by the nematode for several months after feeding on an infected plant, but the nematode no longer carries the virus once it has gone through a molt. The virus persists in the field in infected blueberries and among many broadleaf weeds, including dandelion, chickweed and plantain. Some work done in PA found that 25% of seeds from infected dandelions will give rise to infected plants. Apples are also a host. Control includes roguing out infected plants, and the literature suggests that a ring of symptomless plants around these plants should also be removed. Broadleaf weed control in the grass strips between the rows is critical as the virus may be persisting in these weeds, get picked up by the nematodes, and then transmitted to other blueberries. Grasses are not host plants to this virus. Once the broadleaf weeds are eliminated and infected blueberries are rogued out, do not replant the sites for at least a year. If you are concerned that your blueberries may be experiencing viral problems, contact Scott Pfister at 828-2431 or spfister@agr.state.vt.us

SCOUTING SWEET CORN FOR ECB (adapted from Cornell Extension)

Scouting sweet corn for European Corn Borer (ECB) is easy. It is done to determine the percentage of infested plants in a field, not to see if there is any damage at all. Look for small shot holes and feeding frass on the leaves and tassel. Fields should be scouted once a week; more often when temperatures exceed 80 degrees. Examine at least 5 plants at each of 5 different locations in each field. Multiply the number of plants with feeding damage by four and this is your percentage. It is better to look at even more plants, i.e. 5 plants in 10 locations,  multiply the number showing damage by 2 to get the percentage. Once you know your percentage of infestation you can decide if a spray is needed. The threshold is 15 percent. However, whorl-stage sprays are not recommended on bare-ground corn even if damage is above threshold. Instead, wait until at least 40% of the plants in the field show tassel before spraying. Then apply a second spray in 5 to 7 days depending on temperatures when the rest of the field shows tassel. See the New England Vegetable Management Guide for materials and rates.

CUCUMBER BEETLE BATTLES

Many farms are experiencing high cucumber beetle populations. Some practices listed here are too late for this year but keep in mind for next year. For now, treat hot spots if possible. Insecticide applications made between dusk and dawn, when beetles are most active, may be more effective. The beetles colonize cucurbits and continue to buildup over a two to three week period early in the season. Since beetles often aggregate on early-planted, highly preferred varieties, these can be used as trap crops. Aggregated beetles on trap crops planted along the edge or among less preferred types can be controlled with insecticide before they disperse to the main crop. According to Cornell research, some varieties highly preferable to cuke beetles include: Black Jack zucchini, Big Max pumpkin, Cocozelle summer squash, Green Eclipse zucchini, Seneca zucchini, Senator zucchini, Baby Boo pumpkin, Super Select zucchini, Ambercup buttercup squash, Dark Green zucchini, Embassy Dark Green zucchini, Caserta summer squash and Classic melon. Yellow mulch has also been shown to attract beetles, and could be used to create a ‘trap row’. Row covers will provide protection from beetles early in the season, but must be removed when blossoms appear to permit pollination. Deep plowing and clean cultivation after harvest may reduce overwintering beetle populations. Pesticides labeled for cucumber beetle control on cucurbits include Sevin and Thiodan (both highly toxic to bees, avoid use during blossom time or else spray in the evening) and the pyrethroids Asana and Pounce. Organic growers can use pyrethrum and/or rotenone; some growers are trying it in combination with Surround kaolin clay, which is labeled as a cucumber beetle deterrent.

(Brand names are mentioned for information purposes only, no endorsement is intended. Always follow pesticide label instructions.)