Mint For Success

■ I I L Disease-Resistant Tomatoes

Many varieties of tomatoes have been bred for multiple disease resistance. The diseases are identifier! h v , i after the variety name, as in •Celebrity' hybrid VFFNT. which resists verticillium v ^ ? nematodes, and tobacco mosaic virus. Slrd,ns ^ fusanum

Here'6 a list of what the letters mean:

V: Verticillium wilt

F: Fusarium wilt

FF: Fusarium wilt, races 1 and 2

N: Nematodes

T: Tobacco mosaic virus

A: Alternaria blight (early blight, a leaf-spot disease) ,~ ^TS^H

S: Stemphylium (gray leaf spot)

Nematodes (eelworms) are a pest rather than a disease, though they cause symptoms resembling mild cases of wilt diseases. Most of these wormlike organisms are very small to microscopic. While some are beneficial soil organisms, others, such as root-knot nematodes, harm or kill plants. If plants are stunted and wilt even though the soil is moist, pull up the roots to look for small, beadlike bumps.

Solarizing Soil

Solarization is the process of using the sun's heat to kill off many diseases and weed seeds. Some of the soilborne plant diseases controlled by solarization include fusarium wilt, verticillium wilt, early blight (alter-nana), root rot, damping off, crown gall, and nematodes. Fortunately, beneficial soil organisms can take hotter temperatures than can harmful ones, so this process doesn't destroy the good guys. (Or, at least, enough survive to quickly repopulate the area.)

For the most effective disease control, the soil temperature should reach 114°F (46°C) for three to eight weeks. Lower temperatures will still kill many weed seeds and may also slow the diseases long enough to give your plants the head start they need to get through the growing season.

This technique greatly reduces weeds for at least a year. Minimize tilling or disturbing the soil after solarizing. That way you'll avoid stirring up healthy weed seeds (or nematodes) from deeper in the soil.

Where and When to Solarize

Solarization works best with bright sunlight and warm temperatures. It's most effective in Arizona, southern California, and other regions with hot, sunny, dry summers. Where clouds and cooler temperatures are common, use a second layer of plastic to generate more heat. Choose the warmest, sunniest time of year. In many places this is July and August. Where summer thunderstorms are common, solarizing somewhat earlier or later may give you a longer period of available sunlight. (For metric equivalents, see "Useful. Conversions' on page 208.)

HINT FOR SUCC

Hot Tip for Cool Climates

Using chicken manure afong with solarization can generate additional heat so that only one layer of plastic is needed. In one experiment, 37 pounds of fresh chicken manure were used for 100 square feet of garden. The chicken manure increased the soil temperature 10 to 25°C at a depth of 6 inches. The high temperatures gave 100 percent control of troublesome weed seeds in the top 6 inches. In similar studies, the chicken manure also helped control nematodes.

You can use any fresh (or only slightly rotted) manure if you don't have access to chicken manure. Spread 2 inches deep before turning, and mix it in well.

Materials

Clear plastic sheeting (2 to 4 mil thick)

  • Shovel or filter
  • Rake Soaker hose
  • Soil stakes or heavy stones
  • Empty soda cans (for cooler climates)

jDig up or pull any plants. Rototill or turn over the soil to a depth of < 2 inches. Remove stones, sticks, and other large debris. Rake the surface until smooth, so you won't have to disturb the soil after its been treated.

Water the soil until the top 2 feet are well moistened but not soggy. If your soil is very sandy and well drained, it'll need additional moisture during the procedure, so lay a soaker hose on top. of the soil at 'his pom!.

jDig up or pull any plants. Rototill or turn over the soil to a depth of < 2 inches. Remove stones, sticks, and other large debris. Rake the surface until smooth, so you won't have to disturb the soil after its been treated.

Water the soil until the top 2 feet are well moistened but not soggy. If your soil is very sandy and well drained, it'll need additional moisture during the procedure, so lay a soaker hose on top. of the soil at 'his pom!.

Organic Gardeners Composting

Organic Gardeners Composting

Have you always wanted to grow your own vegetables but didn't know what to do? Here are the best tips on how to become a true and envied organic gardner.

Get My Free Ebook


Post a comment