Preventing Uncontrollable Plant Pestilences
By Avoidance and Plant Selection
(Keeping Devastation Behind Closed Material)

Some gardeners will sacrifice entire plantings of vegetables rather than spray one "poisonous pesticide". Today, an Earth-Kind technique offers an effective alternative. Not only is this technique an alternative to using pesticide applications, it is an alternative to unavoidable annihilation from impossible?to?control pests which defy pesticides with impunity.

Protection from environmental adversities is also a benefit of this Earth-Kind technique. Findings show that a breeze as little as a 15 mph can significantly slow plant growth, delay harvest and decrease yields of vegetable crops. From field experience, hailstones traveling at 80 mph can also inflict a considerable amount of damage to young plants. You can protect transplants, seedlings and fruit from would?be devourers or destroyers with a protective barrier. The most versatile barrier is a covering of polypropylene spun-web fabric-material called floating row cover.

Consider this strategic scenario using cage?like barriers. Transplant tomatoes and peppers into the garden. IMMEDIATELY install concrete reinforcing wire cages around young transplants and wrap the cages with spun-web fabric. Anchor all sides of the cage by with wire attached to supports that have been driven deep into the soil.

Cages can be concrete reinforcing wire, hog wire or similar material formed into cylinders which support plants and keep fruit off the ground. Make the cylinder 18 to 20 inches in diameter and 2-1/2 (called half cages) to 5 feet (the width of the roll of wire becomes the height of the cage) tall. It takes a 5?foot length of wire to make a tomato cage 18 to 20 inches in diameter. Cages are held together by bending and crimping ends of horizontal wires around the opposite end vertical wire. Keep the cage supported and standing by snipping the bottom ring of the cage and pushing prongs into the ground. You can also leave the bottom ring of the cage intact. Wrap cages to the ground with a single layer of translucent, spun?web material, then pile soil 6 inches high around base and firm the soil. Supporting the cage with soil serves as a berm to keep irrigation water from escaping the first few times you water the enclosed transplants.

The fabric is the pest barrier. Do this wrapping in a warm place where cloth relaxes and stretches easier. The ends of this material are folded, then stapled, taped, glued or folded and then clothes-pinned to the vertical wire. Make sure the fabric fits cages snugly to prevent tearing by wind. Adequate anchorage is essential for cages covered with plastic or fabric?like material since, when it’s windy, this structure can also be used as a substitute for a box kite!

Let me warn you not to take a short cut by covering or surrounding several cages at once rather than wrapping individual cages. I recommend spun-web material because it is thin, light weight and translucent. Because it does not shade the plant, most blooms will get plenty of light and will not drop from the plant.

Since no bees or insects can enter, you may wonder if plants will set fruit when covered with the web?like fabric. Tomatoes, peppers and eggplants are 85% self?pollinating??they do not need movement of pollen by insects. Vine crops such as squash and cucumbers MUST be pollinated by insects so once female flowers (flowers with small fruit attached) begin to appear, either remove the floating row cover completely or uncover plants from 7 a.m. until 10 a.m. each morning to allow pollinating insects to enter. Otherwise, hand pollinate enclosed vine crops to set fruit.

Even though it is translucent with a maximum light?transmitting characteristic, row cover can keep blooms from setting if the growing location is partially shaded. Initially, row cover was tested on plants receiving full sun (8 to 10 hours of direct sunlight) conditions daily. When used on plants growing in a full sun condition, row cover can remain in place on a crop for the entire growing season without decreasing yields. In partial shade, row covering may reduce fruit set. To avoid bloom drop, uncover plants when foliage begins to touch the sides of the structure. This will usually be about the time the plant has marble?size fruit.

Wind and Cold Protection

In some parts of the state particularly North and West Texas, March and April may be too early to transplant tomatoes and peppers, especially. The soil is cold, the wind is fierce and a late frost may annihilate plantings. Yet most gardeners feel "nothing ventured, nothing gained."

If you want to plant early, at least hedge your bets and use the floating row cover. One of the advantages of the spun-web fabric?like material over a plastic film covering is that the floating row cover never requires ventilation. If supplemental heat is provided, the cloth?like material does not capture or hold in as much heat as plastic. If temperatures fall below 28 degrees F., provide supplemental heat for fabric?covered plants using Christmas lights or heat lamps.

Some gardeners have decided to take advantage of the superior daytime heat?capturing, nighttime heat?retaining properties of plastic coverings in combination with the slow?thawing, pest excluding properties of floating row cover. These gardeners use a combination of covering materials. The spun?web material (floating row cover) used to wrap tomato cages to provide protection from pests (deer, insects, birds, neighbors) and environmental adversities (wind, hail, cold) will provide a 5?degree F.?below?freezing protection for plants. This means that cages wrapped with floating row cover and anchored to avoid blow?over by March and April winds will usually provide all the protection the early?planted transplants will need in areas of Texas where temperatures seldom drop below 28 degrees F. after March. However, when an outer layer of plastic is added to the floating row cover?wrapped cages, warm-up during the day and heat retention at night will be enhanced. Just as important, the inner lining of floating row cover allows a slow thaw of plant material, avoiding cell damage caused by rapid heating of the morning sun. The insulating effect of the floating row cover layer will also lessen the chance of foliage burn, caused when leaves touch the freezing temperatures of the plastic.

The tops of these plastic-covered miniature greenhouses should be left open during warm days to avoid excessive heat build?up. Leave the tops of the plastic?covered cages open when daytime temperatures rise above 65 to 70 degrees F. Temperatures will be 30 degrees warmer inside the plastic?covered cages. If a cold night is expected, the tops of the plastic?covered cages should be closed several hours before sunset so enough heat can be collected to provide extra protection. The outer covering of plastic should be removed when temperatures regularly reach above 80 degrees F. The remaining floating row cover material will never overheat plants since temperatures are not increased more than 10 degrees F. above daytime highs. The spun-web floating row cover material can also be used for a fall crop planted in July since it will ventilate so plants will not overheat.

Transplants and seedlings can be covered with floating row cover to prevent loss from predation by birds. Row cover can be draped over plants and allowed to "float". The material can be supported over the plants by a super?structure of wood or wire if you fear plant damage caused by wind whipping loose material.

Controlling Tomato Spotted Wilt Virus (TSWV)

Gardeners blame everything from vengeful neighbors to dishonest nurserymen for stunted, non?productive plants that are infected with viruses. No person is to blame. Thousands of insects such as thrips and aphids are the culprits that spread viruses. Insects feed on virus?infected weeds and garden plants, then transmit the virus to another plant. Not all insects spread viruses. Insects known to cause problems include aphids, thrips, white flies and leaf?feeding beetles. Aphids puncture an infected plant with their mouth and draw the virus particles and cell contents into their body.

Some aphid?borne viruses are carried only on mouth parts but others are taken into the gut, circulatory system and eventually the salivary glands. All the aphid has to do is "slobber" on a healthy plant to cause infection. This is why virus prevention is so difficult ?? 100% insect control is impossible as well as impractical using chemical pesticides. Even if you could grow a plant that was full of pesticide and would kill any insect immediately if it damaged the foliage, the virus is delivered the instant the plant tissue is penetrated. Insect sprays are not the answer!

Covered transplants will be protected from virus?carrying thrips and aphids until plants begin to crowd in the cage. Then, remove the floating row cover. Plants covered with spun-web fabric?like material do not require uncovering except to let in pollinators. Unless threatened by devouring pests (deer, rabbits, etc.) or not growing in a full sun condition (minimum of 8 hours direct sun), cross?pollinated plants such as squash, melons and cucumbers thrive better uncovered. Uncovering is recommended once fruit set is underway. An effective degree of virus control will have been achieved and infection delayed a sufficient length of time to insure adequate production since larger plants suffer less severe virus symptoms than smaller ones after becoming infected. Protect young, tender transplants as soon as possible from virus?carrying insects and environmental adversities with the covered cages. Plants that grow to a larger size before being infected show less severe virus symptoms such as foliage distortion, fruit abnormalities, pinto?striped red and yellow, or black and cracked immature fruit, along with a lack of production.

With the onslaught of so many pests and so much pestilence these days, a person has a full time job just trying to stay healthy. Since plants are virtually defenseless, and in lieu of a “Plant Protection Society (PPS)”, gardeners have an obligation to protect their plants. Protected plants will reward gardeners with an abundance of fresh produce. However, plant protection is easier said than done.

As with some human maladies, avoiding contact with a contaminator is the key to health. Some plant pests are so mobile, so minuscule, so elusive, so reproductive and so resistant to chemical pesticides that they are better avoided than faced. Now you know that avoiding contact by using a physical barrier of floating row cover is the best, and many times, the only answer to a healthy, productive plant. Yet some gardeners don't like this system because they cannot easily see their plants. I tell gardeners who love to watch their plants every day that all they have to do is press their face closely to the floating row cover and you can peek at the plants any time they want. The benefit is that ONLY YOU will know how your plants are doing and when the first delicious vegetables will be ready to eat. This may save produce from neighbors as well as other hungry pests!

If you understand the importance of plant protection with floating row cover even though you can't see your plants from a distance, you can become a charter member of the “Parsons' Plant Protection Society (PPPS)”. Some sacrifices are required.

The spun-web, fabric?like floating row cover material is sold at local nurseries as Grow?Web, Plant Shield, Reemay and Plant?Guard Floating Row Cover.

Grow?Web can be mail?ordered from: Indeco Products Incorporated, P.O. Box 865, San Marcos, Texas 78666 Telephone: 512?396?5814
or 1?888?246?3326; email indecoprod@centuryinter.net.

Floating row cover material can be ordered from Gardens Alive, 5100 Schenley Place, Lawrenceburg, Indiana 47025 (Tel: 812?537?8650) or from the Dewitt Company. Call 1?800?888?9669) for the location of a nearby distributor.

Grow?Web, Plant Shield, Reemay and Plant?Guard Floating Row Cover are the only tested materials that allow enough light penetration and air movement to assure proper plant growth and fruit set. The costs of these materials differ, but floating row cover material is much cheaper than plastic. However, these thin cloth?like materials are usually discarded after one use.

How to Avoid TSWV by Using a Resistant Hybrid Variety Named ‘Tomato 444’

Gardeners can now "protect" their tomato crop from non?productivity and/or the odd colored fruit caused by TSWV contamination. There is a hybrid tomato variety named 'Tomato 444' which has natural plant resistance to Tomato Spotted Wilt Virus and the problems it causes. The fruit is large and the quality is excellent. '444' is the only virus resistant hybrid that has been extremely productive as well as resistant to TSWV. Most of the tomato varieties that have done extremely well in this area are hybrids. These include Big Set, Celebrity, Bingo and Merced.

A hybrid is a first generation cross of 2 genetically different varieties. In order to obtain a high degree of uniformity, the parent lines are usually the result of inbreeding for several generations. Producing stock seed in-breeds is a difficult task that may require years to perfect. The resulting crosses produce hybrids that are often sterile. The seed company that developed the hybrid then has an exclusive in sales that helps pay for research, development cost and company motivation for continued research.

Many vegetables require hand pollination to produce the hybrid lines. Labor is expensive and often the costs are reflected in the price of the hybrid seed. In order to reduce costs, some companies use foreign labor and produce their seeds in South America or the Far East. Some hybrid seeds cost as much as 3 to 10 times the price of open?pollinated seed. Hybrid tomato seed can sell for over $40 for 1000 seeds, so hybrids such as '444' will ONLY be available as transplants. The seeds will not be packaged.

Hybrid seed has the advantage of a high degree of uniformity, as all the seeds are very similar genetically. This factor is very important in crops such as broccoli, cauliflower or cabbage. Hybrid crosses also seem to have an additional spark called hybrid vigor. The plants grow rapidly with good uniformity. By producing inbred lines with good disease resistance, the resulting hybrid crosses may inherit these qualities. This is why 'Tomato 444' has resistance to TSWV and other foliage diseases.

Just the fact that a variety is a hybrid does not make it an automatic winner, however. The horticultural merits of a hybrid must also be proven in every growing area, just as those of any other variety released. 'Tomato 444' has been tested for several years by Texas Cooperative Extension with the help of Gardening Volunteers of South Texas and has never failed to produce a large crop of quality tomatoes. You can find yield and size data at:

http://aggie-horticulture.tamu.edu/plantanswers/vegetables/
2001tomatotrials/index.html

It shows that 'Tomato 444' (listed as BHN 444) yielded more fruit that were larger than Merced, Celebrity, Whirlaway, Bingo and Heatwave. This tendency was also repeated in the fall season as documented at:

http://aggie-horticulture.tamu.edu/plantanswers/vegetables/
2001falltomatotrials/index.html

This selection has been test marketed as 'Healthy Surprise' (the plant is "Healthy" and eating tomatoes makes the grower healthy as well, and it will "Surprise" you with an abundance of large fruit!). It is described at:

http://www.plantanswers.com/healthy_surprise.htm

Second generation seed is also available from this website.

Gardeners always want to know how a tomato variety tastes. Tomato taste is an individual preference, so you have to decide that factor for yourself, using the growing conditions in your garden. However, in the variety trial of spring 2000, a taste test revealed that 'Tomato 444' was rated better than 'SunMaster' or 'Celebrity'.