Effects of False Seedbed on the Preventative Weed Control in Organic Rice Paddy Field

Abstract

ABSTRACT. This study was conducted to determine the weed control effect of false seedbed in organic rice paddy field. False seedbed is one of the preventative weed control method, especially effective in upland vegetable field. False seedbed frequency and methods were examined by varying the processing time in greenhouse and field condition in 2012 and 2013. In greenhouse experiment, shallow recultivation and harrow surface soil was effective to control weed up to 70%. Optimal processing time of false seedbed was when the weed was two or three leaf stages. Under field condition, one-time treatment of false seedbed was 61% of weed suppression rate and two-times of false seedbed treatment was 79% of weed suppression rate. Monochoria vaginalis was still troublesome weed after false seedbed treatment, but the occurrence of Echinochloa oryzoides was decreased after false seedbed treament. Results indicated that false seedbed treatment was very effective to lower early weed occurrence in rice paddy field especially Echinochloa spp. Weed control efficiency of shallow recultivation by weeder hollow and rotary tillage by tractor were 68%, 13% respectively.