ประสิทธิภาพของเชื้อแบคทีเรียปฏิปักษ์และสารจากพืชบางชนิดในการควบคุมโรคเมล็ดด่างของข้าว

Abstract

Rice disease surveys had been carried out in the field of highland terrace paddy cultivation at ban na-gean, tambon na-gean, amphoe om-goy, Chiang Mai province which is in the area of highland agricultural development station project. Disease surveys have shown rice seed discoloration was the most severity and important problem in this area. The objective of this study was to test the effectiveness of antagonistic bacteria and some plant extract from tea seed to control rice seed discoloration in highland area. The experiment was designed as RCB with 6 treatments and 4 replications, using Beu Pa Doo rice variety and transplanting method in wet season 2008 and 2009. The treatments were foliar spray with bacterial suspension of antagonistic bacteria Bacillus subtilis No.4, No.9 and No.33 at the rate 60 gram/20 liter of water and foliar spray with plant extract from tea seed at the rate 150 and 250 gram/20 liter of water. Foliar spray were done three times at booting, 5% flowering and 100% flowering stages, while foliar spray with water was control treatment. The result in wet season 2008 was significantly different among treatments. Tea seed at the rate 250 gram/20 liter of water and antagonistic bacteria No.4 gave the good result in controlling disease which percentage of severity were 17.69 and 19.52%, respectively, while control treatment (water spray), antagonistic bacteria No.9, tea seed at the rate 150 gram/20 liter of water and antagonistic bacteria No.33 showed disease severity 21.00, 22.57, 22.97 and 30.07%, respectively. For the experiment in wet season 2009, there was not significantly different among treatments. The result showed tea seed at the rate 150 gram/20 liter of water, antagonistic bacteria No.9, tea seed at the rate 250 gram/20 liter of water, antagonistic bacteria No.33, control treatment (water spray) and antagonistic bacteria No.4 gave the disease severity 18.55, 18.63, 18.68, 19.82, 20.76 and 21.05%, respectively.