Abstract
To clarify the effects of pruning branches of plum, mandarin orange, persimmon, and peach, and bark of Japanese cedar and hinoki mixture for weed control in paddy fields, germination test for Chinese cabbage seedlings under exposure to branch and bark extract and field experiments were conducted. In field experiments, these materials were chopped and spread 100-500 gm-2 at 0-6 days after transplanting, and then the weed species, number, and air-dry or dry weight were investigated at 31-47 days after transplanting. Growth and yield of rice were measured at maturity. In germination test, the extract solution from branches of plum and mandarin orange reduced the number of Chinese cabbages germination. The weed population in field was reduced when more than 200 gm-2 plum or mandarin orange branches were treated;especially weed control treated with plum branch was stable in field experiments. However, there are no differences between dry weights of specified weed and untreated. Rice yield of plum and mandarin orange treatments were lower than untreated. These results suggest that plum and mandarin orange branches are an effective tool to weed control in paddy fields, but the effect of mandarin orange branch is not stable compare with plum branch. And yet these materials may decrease the rice yield.
