Have you heard of chitinase? It is a naturally occurring substance that has potential for preventing or reversing disease in plants. You may be using chitinase right now to fight plant diseases and not even know it. As research on chitinase continues another organic pesticide may be developed that will aid the gardener in preventing or controlling fungal infections as well as insect attacks.
Chitinase is an enzyme that breaks down chitin, a substance found in the exoskeleton of insects and in the walls of fungi. Chitinase has the potential for inhibiting the growth of insects and fungi by destroying their protective covering. Chitinase is produced by several organisms including bacteria and a few plants. Chitanse-producing bacteria are found in garden compost and worm castings ( a euphemism for worm feces or worm poop), used by many gardeners for a variety of other benefits. When compost or worm castings are incorporated into soil, insects can detect the chitinase produced by the bacteria from the compost or worm castings and they leave the area. In addition, some plants can produce chitinase in response to elements in worm castings causing insects pest to leave them alone. This has been demonstrated by the ability of houseplants, roses, and hibiscus to repell spider mites, aphids, and white flies, respectively.
Using compost or earthworm casting in your soil may be a good way of protecting your plants from some harmful pests with chitinase. Better ways of incorporating chitinase into a pest management plan, however, may become available in the future so watch for new developments. In the meantime the use of compost and/or worm castings has many other benefits so their use should be continued.