การใช้ผงเชื้อแบคทีเรียปฏิปักษ์ Bacillus subtilis ร่วมกับสารป้องกันกำจัดโรคพืชในการควบคุมโรคเมล็ดด่างของข้าว

Abstract

Experiments were laid out as Randomized Complete Block Design with 4 replications and 8 treatments. Khao Jow Hawm Khlong Luang 1, which is the most susceptible variety, was direct germinated-seed sown in 32 plots (a plot size 4*4 meter). Three applications with 1.6*10**(9) cfu/ml. of antagonistic bacterial suspention were made at booting, early heading and late heading stage and two applications with 1.6*10**(8) cfu/ml. of antagonistic bacterial suspention mixed with carbendazim+epoxiconazole 25 percent SC (11.25 gm.ai/rai) or propiconazol 25 percent E.C (7.5 gm.ai/rai ) or propiconazol+difenoconazole 30 percent E.C (6.75 gm.ai/rai ), an individual using of carbendazim+epoxiconazole 25 percent SC (22.5 gm.ai/rai) or propiconazol 25 percent E.C (15 gm.ai/rai) or propiconazol+difenoconazole 30 percent E.C (13.5 gm.ai/rai) were made at booting and early heading stage. One week before harvest, 100 panicles were randomly collected from each plot for disease severity examination and yield component of all plot were collected and analyzed The results indicated that the bacterium suspension (B.subtilis No.33, 1.6*10**(8) cfu/ml) mixec with carbendazim+epoxiconazole 25 percent SC (11.25 gm. ai/rai ) or propiconazol 25 percent E.C (7.5 gm.ai/rai) or propiconazol+difenoconazole 30 percent E.C (6.75 gm.ai/rai) fungicides showed the most effective in suppressing the rice grain discoloration disease development as well as an individual using of carbendazim+epoxiconazole 25 percent SC (22.5 gm.ai/rai), propiconazol 25 percent E.C (15 gm.ai/rai) and propiconazol+difenoconazole 30 percent E.C (13.5 gm.ai/rai) fungicides. We also found that using with 1.6*10**(9) cfu/ml. of antagonistic bacterial (B. subtilis No.33) also showed significant difference in suppressing the disease development compared to control plot.