Studies on the Effect of Type and Solarization Period on Germination Percentage of Four Weed Species

In order to study the effects of soil solarization on weed control, an experiment with factorial arrangement in a randomized complete block design with four replications was conducted in a fallow farm in Daregaz in 2008. Factors included solarization duration (0, 2, 4 and 6 weeks) and soil moisture content (dry and moist). Soil seed bank was sampled (in two depth, 0-10 and 10-20 cm) prior to the experiment and immediately after applying treatments, and germination percentage of weed species were determined. Results of this study showed that seed germination percentage in 10 cm soil depth was influenced by soil moisture and solarization and their interactions, while in 20 cm soil depth only solarization period affected the weed seed germination. Germination percentage in moist soil was less than that in dry soil. Seed germination percentage declined more by increasing solarization duration, so that the greatest decline was obtained after 6 weeks solarization. Solarization decreased germination percentage in moist soil more than that in dry soil. Overall, the results of this experiment indicated that solarization of moist soil for 6 weeks was the most effective treatment in controlling common lambsquatres (Chenopodium album), common purslane (Portulaca oleracea), redroot pigweed (Amaranthus retroflexus), and wild mustard (Sinapis arvensis), while solarization of dry soil for 2 weeks was the least effective treatment for weed control.