การใช้สารกำจัดวัชพืชชนิดก่อนและหลังงอกในการควบคุมข้าววัชพืช

Abstract

Study on pre-and post-emergence herbicides application was conducted in farmer field of two sites in Phitsanulok and Prachinburi provinces which are serious infested area of weedy rice during wet season (July to November) 2008. Eight treatments were arranged in randomized complete block with 4 replications. They were 1) dimethenamid 45 g ai/rai 2) pretilachlor+dimethenamid 120+45 g ai/rai 3) alachlor 240 g ai/rai 4) flufenacet+oxadiargyl 18+40 g ai/rai 5) dimethenamid+oxadiargyl 45+40 g ai/rai 6) oxyfluorfen+penoxulam 48+12.5 g ai/rai 7) imazethapyr+pendimethalin 11.2+99 g ai/rai and 8) no herbicide application. Phitsanulok 2 rice variety was planted by pre-germinated seed broadcasting. Results showed that herbicidal toxicity to rice was about 40-50 percent. The efficacy of weedy rice control was about 60-80 percent. The herbicides that showed high efficacy, quite low weedy rice density and reasonable yield were dimethenamid, pretilachlor+dimethenamid, dimethenamid+oxadiargyl and imazethapyr+pendimethalin.