| Abstract: | Studies were conducted at KPK Agricultural University, Peshawar, Pakistan, in June 2008 and 2009 using a randomized complete block design. Plots were covered with transparent polyethylene films for different periods (0, 2, 4, 6, 8, and 10 weeks). The temperature inside the film was about 10 °C greater than the atmospheric temperature. Solarization increased nitrogen (N) and organic-matter levels in both years, probably because of decomposition of plant residues. Increasing the period of solarization decreased weed density and both fresh and dry biomass. The effectiveness of solarization was species specific. In 2008, Cirsium arvense L. was controlled in the solarized soil, whereas Vicia sativa germination was stimulated by solarization. In 2009, suppressed weeds included Sorghum halepense whereas Chenopodium album L., Cyperus rotundus, and Rumex crispus L. were unaffected. Solarization increased yield of cauliflower (Brassica oleracea L.) in both years. These results suggest that solarization should be practiced before planting horticultural crops in areas with a hot climate. |
