[Objective] To select scientific and rational fungicides for the control of rice bacterial leaf streak Xan-thomonas oryzae pv. oryzicola ( Xoc), the control effect and applied dose of eight fungicides against rice bacterial leaf streak was evaluated.
[Method] Rice bacterial leaf streak susceptible rice cultivar Wushansimiao was material. Wushan-simiao at tillering stage was inoculated with dominant virulent strain GDXc1608 of rice bacterial leaf streak isolated from Guangdong area by artificial spraying, and then the disease was controlled by spraying 48 h after inoculation and 7 d after the first application, respectively. The disease index and plant responses to eight fungicides (20% zinc thiazole SC, 50% chloroisobromine cyanuric acid SP, 20% thiodiazole copper SC, 20% bismerthiazol WP, 5% benzisothiazolinone SC, 1.2% xinjunan acetate AS, 3% zhongshengmycin AS and 21.4% cuaminosulfate·copper citrate AS) at the recommended dosage were investigated after the second application. The field efficacy and rice safety of each fungicide were evaluated; and selected four fungicides with better performance and set up three dose gradients in field to carry out pot control experiments in order to determine the best application dosage for the selected fungisides.
[Result] The results of field trials showed that among the eight fungicides, 20% zinc thiazole SC had the best control effect on bacterial leaf streak, with the control effect of 71.81% at the dosage of 450.00 mL/ha, followed by 21.4% cuaminosulfate·copper citrate AS, 20% thiodiazole copper SC and 5% benzisothiazolinone SC, the control effects on bacterial leaf streak were 53.50%, 52.00% and 48.23%, respectively. However, the rice plants treated with 21.4% cuaminosulfate·copper citrate AS showed slight phytotoxicity symptoms; the other fungicides showed poor efficacy. The results of pot experiment showed that the control effects of four fungicides on bacterial leaf streak increased with the increase of fungicide dosage, and there were significant differences among different fungicide dosages ( P<0.05). The control effects of 20% zinc thiazole SC at the dosage of 375.00-525.00 mL/ha were all above 77.00%; the control effect of 20% thiodiazole copper SC was over 62.00% at the dosage of 375.00-525.00 mL/ha. The control effect of 21.4% cuaminosulfate·copper citrate AS was 51.83% at the dosage of 481.50 mL/ha, and the control effect was lower at other test dosages. The control effect of 5% benzisothiazolinone SC was 49.50% and 53.15% at 37.50 and 52.50 mL/ha, respectively. The control effect of 5% benzisothiazolinone SC was low at 22. 50 mL/ha.
[Conclusion] The control effect of 20% zinc thiazole SC on bacterial leaf streak is better, and it can be used as the first choice for field emergency provention and control of bacterial leaf streak. 21.4% cuaminosulfate·copper citrate AS, 20% thiodiazole copper SC and 5% benzisothiazolinone SC also have good control effects on bacterial leaf streak, which can be used alternately with 20% zinc thiazole SC to delay the development of drug resistance. The recommended doses of 20% zinc thiazole SC and 20% thiodiazole copper SC were 375.00-525.00 mL/ha, and the recommended doses of 21.4% cuaminosulfate·copper citrate AS and 5% benzisothiazolinone SC were 481.50 mL/ha and 37.50-52.50 mL/ha, respectively. In order to avoid phytotoxicity, the concentration and spraying time should be strictly controlled when using 21.4% cuaminosulfate·copper citrate AS.
摘要: 【目的】 评价8种杀菌剂对水稻细菌性条斑病的田间防效和使用剂量, 为水稻细菌性条斑病的防控提供科学 依据。 【方法】 以水稻细菌性条斑病感病品种五山丝苗为试验材料, 于五山丝苗处于分蘖期时选用广东地区水稻细菌 性条斑病优势强致病型代表菌株GDXc1608进行人工喷雾法接种, 分别在接菌后48 h和第1次药后7 d采用喷雾法施 药防治, 调査第2次药后8种杀菌剂(20%噻唑锌SC、50%氯溴异氰尿酸SP、0%噻菌铜SC、20%叶枯唑WP、5%噻霉酮 SC、1.2%辛菌胺醋酸盐AS、3%中生菌素AS和21.4%络铜·柠铜AS)在常规剂量下水稻的病情指数和植株反应, 评价 各药剂的田间防效及水稻安全性; 选取表现较好的4种药剂分别设置3个使用剂量梯度开展盆栽防治试验, 筛选目标 药剂的最佳使用剂量。 【结果】 田间防治试验结果显示, 8种药剂中以20%噻唑锌SC的防效最好, 在使用剂量为450.00 mL/ha时对细菌性条斑病的防效为71.81%, 其次是21.4%络铜·柠铜AS、20%噻菌铜SC和5%噻霉酮SC, 对细菌性条斑 病的防效分别为53.50%、52.00%和48.23%, 但21.4%络铜·柠铜AS处理水稻植株出现轻微的药害症状; 其他药剂防效 均较差。药剂使用剂量盆栽筛选试验结果显示, 4种药剂随用药量增加对细菌性条斑病的防效均逐渐提高, 且各药剂 不同剂量间防效均差异显著( P<0.05), 其中20%噻唑锌SC在使用剂量375.00~525.00 mL/ha时的防效均在77.00%以 上; 20%噻菌铜SC在使用剂量375.00~525.00 mL/ha时的防效均在62.00%以上; 21.4%络铜·柠铜AS在使用剂量481.50 mL/ha时防效为51.83%, 其他试验剂量下防效均较低; 5%噻霉酮SC在使用剂量37.50和52.50 mL/ha时的防效分别为 49.50%和53. 15%, 使用剂量为22.50 mL/ha时的防效较低。 【结论】 20%噻唑锌SC对细菌性条斑病的防治效果较好, 可 作为目前细菌性条斑病田间应急防控的首选药剂; 21.4%络铜·柠铜AS、0%噻菌铜SC和5%噻霉酮SC对细菌性条斑 病也有较好的防效, 可与20%噻唑锌SC交替或轮换使用, 以延缓病菌产生抗药性; 20%噻唑锌SC和20%噻菌铜SC推 荐使用剂量均为375.00~525.00 mL/ha, 21.4%络铜·柠铜AS和5%噻霉酮SC推荐使用剂量分别为481.50 mL/ha和 37.50~52.50 mL/ha;应用21.4%络铜·柠铜AS防治时要严格控制浓度和注意喷施时间以避免产生药害。