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

Serious crop losses abound due to heavy rains - many growers lost much of the strawberry crop, and most pea crops rotted on the vine. An entire 5 acre field of sweet corn was washed away by flooding after 6 inches of rain fell in Bradford. There will be widespread gaps in production of lettuce, spinach and other greens. Many crops are N deficient due to leaching - sidedressing is highly advisable this year, the exception being crops on plastic where leaching was minimized. (VG)

Leafhoppers have arrived, but so far not in huge numbers. Trying to keep weeds down to minimize Tarnished Plant Bug (TPB) pressure. Aside from substantial N loss is many fields the rain has not done significant damage. Pollination problems delayed cucumber harvest, replaced poor hives. Harvesting potatoes, those under row cover are very large, seeing some scurf. Many cucumber beetles. Corn under plastic and row cover is silking. Starting to pick peppers, planting late carrots. Carefully pruned greenhouse tomato clusters to 4 fruit this year and they are huge as a result. Lots of woodchucks. (Norwich)

European Corn Borer (ECB) has infested sweet corn at up to 8% of plantings in Connecticut River Valley farms, despite low catches in pheromone traps. (Ray Pestle)

Botrytis on onion and early blight on tomato are more of a problem than in past years. Seeing N deficiency on many crops, but growth problems are worse on heavier soils that remained waterlogged longer. Buttercruch lettuce not headnig up normally. Not much TPB yet. Lots of raspberry cane borer despite reomval of infested canes last year. (Burlington)

Ginseng getting hit by Phytophthora cactorum, which normally infests roots but can also cause leaf lesions. Lesions initially look "water?soaked," then entire leaflets collapse. (Middlebury)

Strawberries getting second wind where they were kept cleaned out, CPB larvae on potatoes and eggplant, applying BT. Virtually no corn borer moth counts but may lose some corn to weed pressure and N loss if we can't catch up with cultivation and additional chilean nitrate side dressing. Green beans in strong, cukes finally ready. Thrips returning somewhat with heat in greenhouse ornamentals. Vegetable & flower sales phenomenal over July 4th weekend. (Dummerston)

We're finally drying out here. Connecticut River exceptionally high thanks to all that Vermont water. Cultivation has been tricky with grasses being difficult to control. Most crops recovered and looking healthy. Some buttoning on Broccol iplants. Fertility has been an issue so we have had to sidedress. Carrots are in, as well as beets, summer squash, greens and lettuce. Green beans in a few days. We picked a handful of field cherry tomatoes. Winter squash is outgrowing cuke beetle damage. Late plantings of carrots and brassicas went in last week. (Amherst, MA)

Help. Make it stop raining. We are in lettuce disaster?land. Our fields are like wet sponges and all the green varieties are tough and pale. Reds are well colored but small. Oddly enough, the future batches are all the same no matter the size. I suspect the amount of water, but they look like they need some N. We are about 3 weeks behind schedule since we can't get a tractor on the land. Mildew still rampant thoug no signs of disease in field tomatoes. Is that how big an
eggplant really should be? (Charlotte)

We've had 2" rain per week, but been spared all but minor flooding. It's been hard keeping sprays on crops and N levels adequate. Moisture levels too high to work some fields for late crops. Using Kocide for early blight in tomatoes. The deciding factor in when to spray has been rainfall rather than duration of leaf wetness as measured by Tom?Cast. Heavy rains (>1/2") wash off the spray and re?spraying is required frequently, every 5?7 days. CPB quite active now and keeping the BT sprays on for the newly hatched 1st and 2nd instars requires frequent re?spraying. Sent samples out for PSNT and am expecting to have to sidedress many crops besides the sweet corn due to the heavy rains. (Starksboro)

The 3?week strawberry picking season rainfall total came to 12 inches, including 3 separate, 2 inch downpours. We just kept trying to come back, like an aging boxer who keeps getting knocked down but doesn't have enough sense to get out of the ring. We brought in gravel where the parking lot got washed out. We laid paths of straw for customers to walk on. We tried to stop topsoil from washing out of the fields by piling stones in newly forming gullies. We took fields out of the picking rotation, letting the berries there rot, to try to keep a smaller acreage picked clean. But the knockout blow came in the third week when we discovered leather rot. The trouble is that the affected berries aren't real obvious visually, so if you, or a customer is picking fast, they'll end up in the basket. But bite into one and you'll double over and gag on what may be the foulest tasting object you've ever had in your mouth. Within 2 hours of discovering it, we closed the farm, aplogized to the customers, laid of the crew, spent the next day fielding calls from irate pickers who had discovered the rot in their berries. We sent them their money back. Then we told ourselves that familiar story about how good things are going to be NEXT year, and carried on. I'm ready to start renovating ?? to close the book on this season ?? but it's rained three inches since we closed. (New Haven)

I reported 2 weeks ago that PSNT levels had remained "average" despite the heavy rains.
Well...it was true at the time, but how quickly things change. Foot in mouth (keyboard?) even before Agriview hits the stands. VERY low tests these past 2 weeks, especially on poorly drained fields, and corn is very N deficient in many fields. Since last reporting, crops in most of those areas with standing water for more than a couple of days are now either diseased or dead. (Sue Hawkins)

Muskmelon and cucumber growers may notice scattered plants that wilt in the field. Typically the leaves wilt first, then the entire vine may die in a few days. To test for this disease, cut an affected vine with a stem about the size of a nickel. Press the two cut ends together and draw them slowly apart. Small sticky strands of sap that hang between the cut pieces are diagnostic for bacterial wilt. This disease rarely affects watermelon and pumpkin. Diseased plants that are observed today are the result of striped cucumber beetle feeding 3 to 4 weeks ago. Therefore no pesticide or fertility spray that will "cure" the vines of bacterial wilt. If the vines are within about 3 weeks of harvest, beetles seldom transmit bacterial wilt. Bacterial wilt will not spread from plant to plant throughout your field. (from Indiana veg crops report)

Via the small fruit discussion list, several extension workers reported the following symptoms on Patriot blueberry plants: fruit dried up and dropped off, terminal leaves small, spotted and leathery, and some other leaves, while normal sized, are thick, deformed and leathery. No spots on the stem or leaves. No red color in the leaves. Symptoms seen for several years now on multiple farms, always on Patriot. Patterns are consistent with a nematode?transmitted virus. Dr. Marvin Pritts says he is hesitant to recommend Patriot anymore because of this problem. It appears we have at least one similar case so far in Vermont. please let me know if you see this on your farm.

STRAWBERRY RENOVATION (adapted from Sonia Schloemann, UMass Extension)
1) As soon a harvest is finished, assess the condition of the bed and decide whether it makes economic sense to renovate and fruit it again. If not, plow under promptly and sow a cover crop. To avoid the buildup of weeds, diseases and insects, organic growers generally plow beds under after fruiting one year, rotate to a new field and replant.
2) If there are a lot of broadleaf weeds, 2,4-D can be applied for postemergent control. Strawberries become semi-dormant this time of year, so they can be sprayed with no risk. Actively growing broadleaf weeds will absorb 2,4-D over 5 to 7 days.
3) Mow off the strawberry leaves 5 to 7 days after the 2,4-D application, as close to the ground as possible without damaging crowns. This reduces the level of inoculum of some leaf diseases as well as populations of two?spotted spider mites.
4) If the ground is compacted, use a subsoiler between the rows. This is especially important for avoiding black root rot which is highly correlated with soil compaction.
5) Narrow rows to 6 to 12 inches using a multivator, rototiller or Lilliston type rolling cultivator, throwing an inch of soil over the top of the row to maintain raised beds and provide soil for new roots to emerge from the crown above the old roots. Strawberry crowns tend to grow up out of the soil from year to year.
6) Apply 40 to 60 lb/acre of actual N, the higher rate on sandy soils, the lower on heavier soils. Make another equal application in early September. A typical way that growers apply 100 lb/acre of N is half at renovation (as 330 lb/acre of 15-15-15) and half on September first (as 175 lb/acre of ammonium nitrate).
7) Apply preemergent herbicide(s). Option 1: Apply terbacil (Sinbar 80WP) at 2 to 6 oz/acre immediately after mowing and rototilling, while there are no leaves on the strawberries. (Sinbar may be applied again in late fall to control winter annuals, but do NOT use more than 8 oz/acre/year total.) Sinbar should NOT be used on soils with low organic matter, or on sensitive varieties. See the label for other restrictions. Follow Sinbar application with Devrinol in about 6 weeks to control winter annual emergence. Option 2: Apply Devrinol at half rate for preemergent control immediately after mowing and rototilling, while there are no leaves on the strawberries. With either option, be prepared for shallow cultivation and some hand weeding to control escapes or odd species.
8 ) Irrigate thoroughy after renovation to help plants through this stress (especially for Jewel which seems to be sensitive to renovation).
9) Before renovation, assess the severity of leaf spot and leaf scorch diseases. Susceptible varieties include Honeoye, Sparkle and especially Kent. If you feel that a fungicide is necessary, apply Thiram 65WP (3 lbs/acre) to new leaves that grow after renovation if rainy weather is expected. Captan or Thiram can then be used as needed in the spring.
10) After new leaves have grown and matured, collect leaves for tissue analysis.