Weed control by solar heating sterilization in the open field.
In a trial in 1989, soil was sterilized using solar heating by covering with polyethylene film for 15 or 31 d. At 26 d after uncovering, the number of weeds with sterilization was 0-26/m2, compared with 131-319 without treatment. Ploughing the sterilized area gave a slight increase in the number of weeds. In 1990, there was a similar effect on the number and wt of weeds in a crop of spinach grown following sterilization. The presence of the crop also decreased weed number, but not as markedly as the sterilization. Investigation of the effects on individual weed species showed that there was little effect on some species whilst others were even increased by sterilization. The treatment was most effective on Echinochloa crus-galli and Digitaria ciliaris.