水稻白叶枯病防治技术研究

STUDY ON THE CONTROL TECHNOLOGY OF RICE BACTERIAL LEAF BLIGHT (XANTHOMONAS ORYZAE)

应用中国农科院最新研制的农用抗生素中生菌素研究了其对水稻白叶枯病的防治效果和应用技术。室内浸种试验表明,用中生菌素100mg/kg、在水温58℃下浸稻种48h,可全部杀死种子表面及内部的白叶枯病菌,切断了种子带菌传病的途径。田间试验表明,用中生菌素50mg/kg、水温55～60℃的药液浸种48h,再于秧苗3～4叶期和移栽前5～7d用中生菌素15mg/kg施药保护,田间白叶枯病可迟发生20d以上,其发病程度亦显著降低,对于轻病田或轻发生年份大田可免于防治;重病田或重发生年份于发病初期再用中生菌素15mg/kg防治1次,即可控制病情的发展。作者认为用中生菌素浸种及秧田期施药保护不仅改变了以往田间发病初期用药防治的策略,而且大大降低了防治费用,经济效益、社会效益及生态效益显著。

The control strategy of rice bacterial leaf blight was studied with a new agricultural antibiotic Zhongshengmycin (substance metabolized by Streptomyces lavendulae var. hainanensis). The results of a soaking rice seeds in laboratory revealed that bacteria either on the surface or inside of the seeds were completely killed, while rice seeds were soaked in 100 mg/kg solution of Zhongshengmycin in water with initial temperature 58℃ then cooling down to room temperature (about 25℃) for 48h. The source of infection by seeds was effectively stopped. The results in a field test showed that rice seeds were soaked in 50 mg/kg solution of Zhongshengmycin in water with initial temperature 55 - 60℃ > then cooling down to air temperature for 48h before sowing; 15 mg/kg solution of the fungicide was sprayed on rice seedling at the 3 or 4-leaf stage of rice and 5 -7 days before transplanting, it was able to delay the disease to occur 20 days or more in field, and reduced the disease severity significantly ,compared with the check. In case of light diseased fields or not prevalent years, such a treatment was enough to prevent rice from the damage of the disease in whole growth period. However, in case of heavy diseased years, it is necessary to apply one spray of 15 mg/kg solution of the fungicide at early August which was able to restrict the development of the disease efficiently. The control strategy of application at the first appearance of the disease in rice fields were replaced by soaking rice seeds and protection at seedling bed with Zhongshengmycin , but might significantly reduced the cost of control. The remarkable economic benefit , social benefit and ecological benefit were achieved.