November 1, 1999
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967


North Country Fruit and Vegetable Seminar, Nov. 3, 9:30-3:30. Cabot Motor Inn, Route 2 (east), Lancaster NH. Topics: Drip Irrigation, Weed Management in Vegetables, Giant Pumpkins, New Tools for Insect Control, Brambles and Berries for the North Country. $13 at the door includes lunch and trade show.

Cabbage in the New Millennium. January 11-13, 2000, Niagara Falls Canada. The conference starts with a tour of cabbage storage and processing facilities in Ontario followed by educational sessions on new markets, consumer trends, food safety issues, what's up and coming for weed, insect and disease management, variety evaluations, maximizing storage potential, and news from industry sponsors. Anu Rangarajan, Cornell Cooperative Extension (607) 255-1780

A Whole Farm Approach To Soil Fertility And Weed Management, with farmers Eric and Anne Nordell, Gunther Hauk and Dave Colson being the presenters. Friday, Jan. 28 afternoon thru Sunday Jan. 30 afternoon in Tunbridge, VT. Contact Tim Sanford at (802) 763-7981 or

North American Strawberry Growers Assn., North American Bramble Growers Assn. and International Ribes Assn. (concurrent meetings): February 14 ? 17, 2000. Primadona Resort, Primm Valley, Nevada (35 miles south of Las Vegas) Room Rates: $22 per night (yes, twenty?two). Contact: Erin Griebe, 517?548?4990 or

PHYTOPHTHORA ON PUMPKINS (Adapted from Illinois Extension and others)
This problem appears to have been rather severe in Vermont in 1999, causing major economic loss on several farms. Since cultural practices aimed at prevention are key to managing this disease here's some info to help you plan for next year. In pumpkin and squash fields, the most obvious symptoms of phytopthora blight are fruit rot and collapse and death of the vines. Soft rot areas with white cottony mold are clearly seen in the infected fruits. Infection of the fruits often begins on the side contacting the soil. Pepper, eggplant and tomato are hosts as well as pumpkin, squash and melons. So, if your fields do have Phythopthora, you will need to rotate out of these crops for a minimum of 3 years. Be sure to clean soil off of equipment when moving from fields with a history of this disease problem into new fields you are rotating to. Otherwise, you may spread the disease inoculum and negate the benefit of rotation. Power-washing the equipment would be best; a strong hosing and banging with a tool to knock most of the soil off is a minimum precaution.

No pumpkin or squash varieties with measurable resistance to Phytophthora blight are available. However, in Illinois, jack?o'?lantern pumpkins appeared to be less susceptible than some larger pumpkins. Three squash varieties, Acorn, Blue Hubbard, and Ornamental Gourds, were found severely diseased, while other squash varieties (e.g., Turks Turban and Butternut) had little or no infection. The incidence of Phytophthora blight can be reduced by planting on raised beds and well?drained soil, since the disease spreads in soils that remain wet. If the site is compacted, pre-plant sub-soiling to enhance drainage is advisable. Some fungicides can reduce the incidence of Phytophthora blight in peppers, eggplant and tomato. Ridomil Gold/Bravo is listed as a fungicide for control of Phytophthera on pumpkin and squash in the New England Vegetable Management guide, however, fungicides may not be a very practical solution since it is difficult to apply the material in a way that protects the area where fruit is in contact with the soil.

POTATO STORAGE (Adapted from Minnesota Extension and others)
Before storage, potatoes should be culled and cured. Cull out and discard any damaged, diseased or frozen tubers. Curing potatoes heals the skin, making it less susceptible to damage and disease. Cure potatoes by exposing them to temperatures between 50 and 60 degrees F and 95% relative humidity for 10 to 14 days. Tubers should be dry when placed in storage, and the storage air temperature and humidity should be managed so that the tubers remain dry. Condensation of moisture on tubers, resulting from air circulating through the tubers that is warmer than the temperature of the tubers, will cause any late blight fungus present to form spores, and late blight will spread in the pile. Potatoes should be held at the lowest temperature possible consistent with their ultimate use (table stock or processing). Most fungi do not grow much at temperatures of 38 degrees F or lower, but some development will occur at higher temperatures.

Hold table potatoes at 38 to 40 degrees F. Store processing potatoes at 50 to 55 degrees F. Processing potatoes stored below 40 degrees F will build up sugars that will cause the flesh to turn brown or black when fried. Do not expose potatoes to temperatures below 30 degrees F, or freezing injury will occur, leading to rot. Humidity in storage should be 95%, but avoid moisture condensation on tubers and storage walls and ceilings. When diseases such as late blight and Pythium leak are severe, maintain lower humidity during storage and ensure good air circulation.

RASPBERRY PRUNING (adapted from Ohio State Extension)
Raspberry canes are of two types, primocanes and floricanes. Primocanes are first year canes while floricanes are second?year fruiting canes. Summer red raspberries should be pruned twice a year, first in the spring and immediately after harvest. The spring pruning, in late March or early April, consists of removing all weak canes and cutting back tall canes (over 5 feet) to 4.5 to 5 feet. The second pruning consists of the removal of floicanes canes that produced fruits, right after harvest. Everbearing red raspberries such as "Heritage" raspberry can be pruned to produce fruit once a year or twice a year. If you follow the pruning methods used for summer red raspberries, "Heritage" raspberry will produce fruit once in spring and once in fall. However, many growers mow or cut all "Heritage" canes to the ground in early spring (March or April) for the sake of simplicity. "Heritage" raspberry pruned this way will produce only one crop starting in late summer.

Black and purple raspberries are pruned three times a year: in the spring, summer, and after fruiting. First pruning is done in spring when lateral branches are cut back to 8 to 10 inches in length in mid-March. Second pruning is called tipping or heading of new canes or primocanes. When grown without supports, summer tipping is done when black raspberry canes reach 24 inches in height and when purple types reach 30 inches. Tipping is done by removing the top 2 to 3 inches of new shoots as they develop. Third pruning involves the removal of canes that produced fruits, right after the harvest.

MULCHING STRAWBERRIES (Adapted from Univ. Of Kentucky)
Strawberry plants must have winter protection with a mulch of straw or other material. Unmulched plants can be seriously damaged by heaving, and cold weather can hurt crowns. Injury from heaving breaks off the fine roots and is not easy to see but can reduce yields significantly. A mulch serves many purposes. It also retards growth during early spring, protecting blooms from spring frosts. It also helps reduce weed growth, conserves moisture, makes picking more pleasant, and keeps fruit clean. Wheat straw is the preferred mulch material for strawberries, although oat and rye straw also work well. Leaves tend to pack too much, sawdust may tie up nitrogen, hays usually contain large amounts of weed seed, and pine needles are not plentiful. If weed? and grain?free straw is not available, straw should be piled loosely near the planting in early fall so that weed and grain seeds may germinate and freeze, thus reducing weed problems in spring. Distribute baled straw over the field in early fall and clip the twine for the same reason (so that rain will wet the straw and seeds will germinate). Apply about 1.5 to 2 tons/acre by hand or with a mulching machine.. Machines are also available that spread large, round bales. Some growers have spread straw by hand by unrolling the straw from large, round bales off the bale spear.

Apply mulch when the temperature is expected to reach about 20°F and the strawberry leaves are beginning to change from green to gray. In Vermont, this is usually in late November. Don't wait too late, since temperatures of 12°F to 18°F can injure plants and reduce bloom. In addition, frozen bales are hard to spread. Many growers produce their own mulching material. Allow the small grain crop to head and mow it before the grain forms, then cure and stack it until needed. Thickly planted Sudan-grass also produces a good mulch for strawberries. However, it must be run through a hay conditioner at cutting and it dries very slowly. One?half acre should produce enough mulching material for one acre of strawberries.

Don't hurry mulch removal in the spring, so strawberry fruit buds stay protected. Unmulched plants usually bloom early and frequently are injured by spring frosts. Remove the mulch when plants have started new growth and the new leaves are slightly yellow. If the mulch is heavy enough to retard growth, rake part of it to the middle of the rows. The plants will grow through the remaining mulch. Leaving the mulch over the plants too late in the spring substantially
reduces yields. If a killing frost is expected, save your crop by raking the straw over the plants again.