Chemical-free method for controlling diseases and nematodes
Soil pests in vegetable and fruit crops, which are causing so much damage in Africa, can be controlled by applying pesticides before planting. However, this use is undesirable because of their toxicity to animals and humans, their residual toxicity in plants and soils, the complexity of soil treatment and their high cost.
Soil solarization is a non-pesticidal method of controlling soil pests by placing plastic sheets on wet soil during periods of high ambient temperature. Plastic sheets allow the sun’s radiant energy to be trapped in the ground, warming the upper levels.
Solarization during the hot summer months can raise soil temperature to levels that kill many pathogens, nematodes, weed seeds and seedlings. It leaves no toxic residues and can be easily used on a small or large scale.
Soil solarization also improves soil structure and increases the availability of nitrogen (N) and other nutrients essential to plants. Solarization is a simple, safe and effective method that has been used with field crops, vegetables and flowers and in orchards, vineyards, greenhouses and gardens for about twenty years.
It can be combined with organic soil amendments or reduced pesticide application rates for greater efficiency. Plant growth, harvestable yield and crop quality increase significantly in solarized soils and can continue for more than one growing season.
The potential for using soil solarization to control diseases and pests in the warmest regions is excellent. This publication is a brief introduction to soil solarization.