Soil Solarization, an Eco-Physiological Method of Weed Control
eeds are the plants growing out of a place where they are not desired for a particular period of time. Weed problems have turned into a continuing struggle for farmers on account of the pressure to raise crops and maximize crop production to meet increasing demand of the fast growing human population. Weeds are the scarce and silent robbers of plant nutrients, soil moisture, solar energy and also occupy the space which would otherwise be available to the main crop; harbour insect-pests and disease causing organisms; exert adverse allelopathic effects; reduce quality of farm produce and increase cost of production. Weeds, unlike other pests, are omnipresent and account for at least one-third of this loss. Losses due to weeds are higher than those from insects and diseases – insects 30%, weeds 45%, diseases 20%, other pests 5% (Rao, 2000). Therefore, efficient weed management approach is expected to contribute significantly in sustaining agriculture. There are several methods for controlling weeds such as cultural method, manual and mechanical method, chemical method, allelopathy and integrated approach. The most practised one is hand weeding but it is laborious, timeconsuming, costly and also is not feasible under all situations. Now-a-days, for effective and economic weed control, herbicides are gaining popularity among the farmers. Out of total pesticide use, 17% is herbicides. The compound growth rate of herbicide consumption has been 13.7% against – 3.88% of insecticides for the last one decade (Aulakh, 2005). But the continuous use of herbicides poses many problems such as, it 1. causes health hazards 2. pollutes the environment 3. contaminates drinking water 4. contaminates the soil and terrestrial system 5. contaminates food and agricultural produces 6. contaminates aquatic and marine products 7. causes toxicity to the succeeding crop 8. develops resistance in weeds 9. causes shift in weed flora. Therefore, interest in non-chemical approaches which aim to
