Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, March 15, 1990< TAG: 9104050088
SECTION: LAWN & GARDEN PAGE: 2 EDITION: EVENING
SOURCE: Charles Stebbins / Correspondent
DATELINE: LENGTH: Long
The main concern in all of this research has been to find elements that will knock out the unwanted without harming the wanted.
That means, for instance, developing an ingredient that will do in potato-killing beetles without harming beneficial ladybugs which consume aphids. That ingredient is Bacillus thuringiensis but the ladybugs themselves eat beetle eggs.
The home gardeners who want to avoid harsh chemicals have many organic type aids at their disposal, in addition to the beneficial insects such as the ladybug, the green lacewing and variow types of parasitic wasps.
Some of the more common organic materials for disease and insect controls include:
Detergent and soap: Ordinary household detergent or soap, suds in water, makes a spray effective to some degree against soft-bodied insects.
Sabadilla: This is one of the specialities of Necessary Trading Co. which markets it under the Red Devil trade name. It controls a wide range of insects either as a contact killer or stomach poison, but is safe for the environment because it breaks down in about a day in sunlight. It can be used as a dust or spray with 8 to 12 tablespoons making a gallon of spray. The cost is about $8.75 for a pound. Sabadilla comes from the seed of a Mexican and Central American plant of the lily family. It is one of the oldest pesticides known and is believed to have been used more than 1,000 years ago.
Sulfur: It comes in both liquid and dust and is used to control diseases such as mildew, scab, leaf spot, brown rot. The cost is about $7 for 24 ounces of liquid.
Copper: This acts as a fungicide and controls common diseases in vine crops such as potatoes, tomatoes, peppers; early and late blights, anthracnose, bacterial spot, leaf spot, rust, Septoria leaf spot, downy mildew, powdery mildew, scab. Also similar fungus diseases of other vegetables and flowers.
Copper comes in both liquid and dust. Dust costs around $10 for 4-pound bag and liquid about $8.75 per pint. Liquid type is mixed with water and a pint can be made into 34 gallons. Copper can be mixed with rotenone to create a fungicide-insecticide all-purpose spray or dust. It can be bought already mixed for about $15 for 4 pounds.
Rotenone (also called derris): This is a classic organic material for insect control. It comes from the root of a tropical plant and has low toxicity to humans and warm-blooded animals.
It can control insects that attack both vegetables and fruits.
Rotenone usually comes in a 5 percent strength and is available in dust, but the dust can be mixed with water to make a spray. The cost is about $11 for a 12-ounce can.
Pyrethrum: An insecticide made from the dried flower heads of several old-world chrysanthemums. It has quick "knockdown" capability on many insects. It kills by paralyzing the insect. Pyrethrum has no residual effect and must be applied directly to the insect to be effective.
Ryania: An insecticide which is a mixture of alkaloids from stems of a tropical South American shrub.
Pyrethrum, rotenone and ryania are often available in a mixture to control a wide range of insects. Pyrethrum knocks down insects quickly and rotenone and ryania combine to put them out of commission permanently: A mixture of this type costs about $8 for 8 ounces.
Micronized sulphur: This is dusted onto fruit plants at pre-blossom stage to help control cedar-apple rust, black rot, brown rot, leaf spot, powdery mildew, quince rust and scab.
Nicotine sulfate: A tobacco by-product that helps control aphids, young scales, leafhoppers, mealybugs, leaf miners, thrips, lace bugs and many others. This product is highly poisonous and should be handled with care. But it biodegrades rapidly and does little harm to the environment.
This comes as a concentrated liquid and one ounce will make two gallons of spray. The cost is around $7 for 5 ounces.
Bordeaux mixture: This is an old standby spray to help control fungus on apples, peaches and grapes. It is formulated from a mixture of copper and lime. The cost is about $5.25 for a pound.
Horticultural oil: This is a dormant oil which kills overwintering insects and their eggs. It is not a poison but kills by suffocation. It is mainly used on fruit trees and is applied in the fall after leaves fall and again in the the early spring before buds open. The cost is about $6.50 for a quart.
Bacillus Thuringiensis (BT): A bacteria that makes insects deathly sick but is harmless to humans. This is sold under various trade names, among them Dipel, Thuricide and Biotrol. It is used against a number of common pests of vegetables and fruits. The cost is about $7.25 for 8 ounces of wettable powder and $8.50 for 8 ounces of liquid.
Milky Spore Disease: This is a disease used only against Japanese beetle grubs. It takes several years for effective control but the spore remains dormant in the soil and will become active again if more grubs appear. The cost is around $13.75 for 10 ounces.
by CNB