Thursday, February 16, 2006
Neem In the News
Neem is the Worlds Safest Insecticide! You Need to Know What Neem is, Too! As early as 4500 years ago, people have used the Neem tree for a wide variety of medicinal and pesticide purposes. Branches, fruit, and leaves from the Neem tree have been used to treat and cure many illnesses. Everything from bad teeth and bedbugs to ulcers and malaria. People brush their teeth with the twigs, rub the oil on their bodies, and put the leaves in food storage containers. Although the uses of the Neem tree are broad in the human experience, we will limit our discussion to its use as an insect repellent and pesticide. As an insect repellent it has been used for thousands of years in food storage bins. Studies have shown that one neem compound is a more effective insect repellent than the widely used synthetic chemical known as DEET , a suspected carcinogen and not recommended for small children. "Neem Extracts and Oil" have been approved by the U.S. Environmental Protection Agency for use on food crops. It's nontoxic to birds, animals, beneficial insects or man and protects crops from over 200 of the most costly pests. The neem tree (Azadirachta indica) is a tropical evergreen related to mahogany. Native to east India and Burma, it grows in much of southeast Asia and west Africa. Neem trees may reach up to 50 feet tall and are reported to live for up to 200 years. Its blooms are small, white flowers with a very sweet, jasmine-like scent. Its edible fruit is about 3/4 of an inch long. Toxicity Azadirachtin, the primary active ingredient in neem oil, is registered in the United States as a general use pesticide with a toxicity classification of IV (relatively nontoxic). Products containing azadirachtin must bear the signal word, "Caution" or "Warning", on their label. Neem oil is not recommended for internal consumption, even though it is consumed frequently in small doses in India. However, when an experimental amount of debittered neem oil was prepared according to WHO and FDA guidelines, the oil was determined to be safe for human consumption on a par with other seed oils. Neem as a Botanical Insect Repellent Neem has been used for thousands of years as an insect repellent for both people and food crops. One compound (salannin) found in neem leaves, seeds, and seed oil, is a safer but, more effective insect repellent than the widely used chemical ingredient, called DEET, currently found in most commercial repellents. Neem extracts, tested by the Malaria Institute, were found to repel the mosquito that causes malaria, for up to twelve hours. Neem provides protection from not only mosquitoes but, also from biting flies, sand fleas, and ticks. Because of neem's proven effectiveness, insect repellents made with neem are being used in, malaria prone, tropical countries. Agricultural Insect Control It is in agriculture that we find most of the research on neem being conducted today. After studying over 250 plants that exhibited insecticidal properties, the consensus of world scientists was the neem proved to be the most effective and, most environmentally friendly, of them all. Pesticidal products made from neem are just now reaching the attention of the public and can be purchased at agricultural supply houses or, ordered through the mail from well-known garden supply manufacturers. Neem promises to provide a truly natural alternative to synthetic insecticides. In 1990, over 30 million pounds of synthetic insecticides were applied to residential gardens and lawns in the United States. Usually, these insecticides were quick-acting nerve toxins, designed to kill any insect, including beneficial insects like bees, on contact. Although they are targeted at insects, these broad-spectrum insecticides can harm any creature that lives in or passes through areas in which they have been sprayed. This includes earthworms, birds, squirrels, dogs, cats, and even people. Most manufacturers of insecticides used in the yard recommend waiting three days before walking barefoot on the sprayed areas and to keep pets and children away for at least that long. As a safety precaution in many cities, signs must be posted to warn the public that a hazardous chemical has been applied to the lawn. People living as much as a quarter mile away from the insecticide application can be affected by evaporated insecticide and aerosols drifting in the air. In some individuals, this can result in severe reactions like headaches and numbness in the limbs. In others, it can cause less noticeable effects that might never be connected with the true cause of the reaction, toxic insecticides being applied somewhere in the neighborhood. Neem's natural properties pose no danger of toxic reactions. The seeds and leaves of the neem tree are the source of a new class of "soft" pesticides. The term "soft" pesticide is used because no other word quite fits this remarkable product. The active insecticidal compound found in neem is azadirachtin, a naturally occurring substance that belongs to an organic molecule class called tetranortriterpenoids. It is structurally similar to insect hormones called "ecdysones," which control the process of metamorphosis as the insects pass from larva to pupa to adult. Metamorphosis requires the careful synchrony of many hormones and other physiological changes to be successful, and azadirachtin seems to be an "ecdysone blocker". It blocks the insect's production and release of these vital hormones. Insects, then, will not molt, thus breaking their life cycle. Azadirachtin also serves as a feeding deterrent for some insects. Depending on the stage of life-cycle, insect death may not occur for several days. However, upon ingestion of minute quantities, insects become quiescent and stop feeding. Residual insecticidal activity is evident for 7 to 10 days, or longer, depending on insect and application rate. Elimination of the insect pest occurs not by quick poisoning, but by starvation and drastic reductions in offspring. Birds and beneficial insects, which are not affected by neem, then feed on the remaining weakened pests and the small number of remaining offspring. The result is an almost-immediate halt to plant damage -- without poisoning the environment. Neem is nontoxic to animals and people. Areas sprayed with neem are not poisonous areas to be avoided for days, as are those sprayed with the typical synthetic insecticides. Neem is also a natural, biodegradable product. Only insects that eat plants are affected by neem, leaving honeybees and other beneficial insects essentially unharmed. As important as azadirachtin is, neem's true effectiveness comes from the interaction of all of the compounds which affect different aspects of an insect's life. Other compounds act as insect repellents, cause insects to lay sterile egg cases, prevent molting, and others simply enhance the effects of other compounds. The number and complexity of the compounds found in neem, that affect insects, make resistance to neem highly unlikely. This is extremely important as insects are rapidly developing resistance to the major synthetic insecticides. More and more insects are even developing resistance to natural bacterial controls, like Bacillus thuringensis (Bt). Farmers in Mexico and Haiti, and shepherds in Australia, have begun switching to simple, neem-based, sprays from the usual synthetic chemical pest controls. This has allowed the farmers to export mango and other fruit to the United States without the chemical residues that often stopped their shipments at inspection stations. Neem-based sprays have similarly allowed the shepherds in Australia to produce a pesticide-free wool that is being sold to European buyers for a considerable premium over the standard wool, impregnated with chemical pesticides. Food Storage Throughout the tropics much of the food harvested is lost during storage. More affluent farmers can and do spray their stored food crops with chemical pesticides to prevent worms, beetles and other infestations. Neem offers the impoverished farmers and even affluent farmers wanting to replace pesticides a natural and inexpensive alternative. A light coating of neem oil protects stored food crops for up to twenty months from all types of infestations with no deterioration or loss of palatability. Soil Amendment - Neem Cake After the oil has been pressed from the seed kernels, the remaining material is called "neem cake." This material has been used for many centuries throughout India as a soil amendment. Experience has taught farmers there that working the leftover neem cake into the soil of a garden produces larger, healthier plants that have few problems with insect pests. Several studies were done to find out why plants grew better in soils mixed with neem cake. The studies discovered that neem cake was richer in plant nutrients than manure, killed damaging nematodes, promoted larger populations of earthworms, helped keep nitrogen in the soil available for the plants, and provided significant protection from insects. This combination of effects provides an almost ideal growing condition for the plants. By killing nematodes in the soil, a major plant pest is eliminated. Nematodes suck the juices from the roots of plants to the point where they are unable to supply sufficient nutrients to the plant. The plants look sickly, fail to grow and may eventually die despite sufficient food, water and care. On the other hand, by promoting larger populations of earthworms, neem cake helps keep the soil loose so that water and nutrients can more easily be absorbed by the roots. Earthworms also enrich the soil by creating readily absorbable nutrients as it feeds on decaying plant material. Neem cake also reduces the nitrification rate of the soil by suppressing nitrifying bacteria such as nitrosomonas and nitrobacter bacteria. This reduces the need for applications of external nutrients. Some studies have shown that mixing neem cake with regularly scheduled applications of manure can almost double crop yield over manure alone. Don't miss out on the benefits of this safe and effective insecticide. Check out Yardiac's Neem products, as well as our other environmentally friendly garden aids!!