What is Bt? “Bt”, first discovered in Japan in 1901, refers to a spore-forming bacterium, Bacillus thuringiensis, which occurs naturally in soils. Some leaf-feeding caterpillars (larvae of butterflies and moths) are killed when they eat very small amounts of leaves or other plant parts that have been coated (sprayed) with Bt. Thousands of strains of … Read more
Certain insects can be controlled by dusting the plants with wood ash. It is a method that can be used especially on smaller plots of vegetables, for example in the cultivation of okra, peppers and certain cucurbits. Wood ash is particularly effective in controlling aphids. It is a simple, non-toxic method, which can be used … Read more
Weeding is an important control method practiced in many crops. The removal of weeds is useful because these unwanted plants compete with the crop for space, water and nutrients. Weed control should usually be done in an early crop stage, as this is more practical (the weed plants are smaller) and more effective. Often, the … Read more
Just spraying water, especially in water jet spraying will control a number of insects especially the smaller ones. Aphids, plant hoppers, small caterpillars and other insects will be simply washed of the plants. Of course with water spraying also populations of natural enemies will be affected, especially the smaller ones (e.g. egg parasitoids). See also … Read more
Insects can be infected by certain viruses which can help reducing insect pest populations. For example some caterpillars are very sensitive to Baculoviruses. Virus infested caterpillars can be easily recognized in the field. In the beginning they often change to a whitish color and become less active. Often they migrate to the higher parts of … Read more
In all crops, different varieties exist with specific characteristics. There are for example rice varieties of short duration (100 days) and long duration (150 days) and there are tomato varieties with round fruits and with elongated fruits. For many crops, there are also varieties that are resistant or tolerant for certain insects or diseases. For … Read more
The name Trichogramma refers to a number of tiny wasps belonging to the family Trichogrammatidae. They are stout-bodied, minute wasps, which can hardly be seen without a hand lens or microscope. Trichogramma is an important bio-control agent as they are egg parasitoids, mainly of Lepidopteran eggs. Up to three wasp larvae may develop in each … Read more
Certain microorganisms exist that can kill plant pathogens or reduce their populations. These are called antagonists. A well-known antagonistic fungus is Trichoderma sp., which is commercially available in several countries including Thailand. Trichoderma can be used to suppress soil-borne pathogens that cause diseases such as damping-off, root rots, stem rots, and wilting in many vegetables. … Read more
There are different types of traps that can be used to catch insects. Traps are usually used for monitoring insect populations, but some traps can also be used to for controlling pests. The efficiency of traps depends partly on the mobility of the insects. Therefore traps are usually more effective in catching adult insects. When … Read more
(under construction) See also: Tagetes
