芝麻青枯病发生特点及药剂防治技术

青枯雷尔氏菌（Ralstonia solanacearum）引起芝麻青枯病，制约我国南方芝麻生产。为制定精准的药剂防治技术，在江西省南昌县建立4年的病害观察圃上试验5种药剂，研究适宜药剂和用药时期。结果发现，芝麻青枯病多于现蕾期前后开始发病，初花期病情指数增长率均最为急剧，因此可选择芝麻定苗时进行药剂喷淋护根，初花始期及其后10d左右再各喷施药剂1次为佳防治适期；300g.ai/hm2的20%噻菌铜对芝麻青枯病的防治效果最好，达71.11%~74.25%%，增产率33.95%~36.73%。2017-2018 年试验结果显示，20% 噻菌铜（300g.ai/hm2）、20% 噻唑锌（300g.ai/hm2）、3%中生菌素（22.5g.ai/hm2）和72%农用链霉素（216g.ai/hm2）对青枯病的防效范围为70.02%~75.23%； 芝麻增产范围为32.14%~35.63%，4种药剂的防效和增产幅度差异均不显著。 

Feature and chemical control of sesame bacterial wilt caused by Ralstonia solanacearum

Bacterial wilt, caused by Ralstonia solanacearum, is responsible for great losses to sesame in south? ern China. To develop a precise chemical approach to control the disease, 5 chemicals were tested at different dates and applications. Results showed that: the disease appeared mostly in bud stage and peaked at initial flowering stage as evidenced by dramatic growth rate of disease index. When seedlings were sprayed with the bactericides at initial flowering and the following 10 days, the control effects were 71.11-74.25% by 20% thiodiazole copper (300 g ai/hm2) which led to 33.95-36.73% yield increase of sesame. During the tests in 2017-2018, control effects of 20% thiodiazole copper (300 g ai/hm2), 20% Zn thiazole (300 g ai/hm2) and 3% zhongshengmycin (22.5 g ai/hm2) were among 70.02% to 75.23%, with sesame yield increase of 32.14-35.63%. Both control effects and yield in? crease showed no significant difference among the 3 bactericides.