鸭跖草致病菌草茎点霉SYAU-06水分散粒剂配方筛选

Formula selection of Phoma herbarum SYAU-06 water dispersible granule againgst dayflower

草茎点霉Phoma herbarum SYAU-06菌株分离自罹病的鸭跖草叶片,可高度侵染鸭跖草导致其死亡,但对大多数农作物安全,具有开发成真菌除草剂的潜能。通过载体和助剂与草茎点霉生物相容性研究,在确保载体和助剂对菌株SYAU-06安全的基础上,比较了各种助剂及其不同用量下的理化性能,确定了草茎点霉SYAU-06水分散粒剂(WG)最佳配方(质量分数)为:草茎点霉SYAU-06发酵菌丝体15%,润湿剂拉开粉(BX)6%,分散剂亚甲基双萘磺酸钠(NNO)4%,崩解剂硫酸铵6%,黏结剂聚乙二醇(PEG 4000)4%,稳定剂碳酸钙5%,载体白炭黑60%。由此配方制备的草茎点霉WG各项指标均合格,其活菌含量为2.55×10^8 cfu/g,润湿时间28.16 s,崩解时间70.50 s,悬浮率88.90%,pH值6.97,含水量1.47%。采用茎叶喷雾法测定了所制备草茎点霉WG对大豆田鸭跖草的田间防效。分别以制剂用量1305、1740、2175和3480 g/hm2的剂量茎叶喷雾施药3次,21 d后鲜重防效分别为50.89%、55.97%、60.67%和69.88%。

Phoma herbarum SYAU-06 isolated from diseased leaves of dayflower was expected to be a candidate of mycoherbicide,which could cause the death of dayflower by effective infection and was safe to most crops.In this study,the biocompatibility of different carriers and adjuvants with P.herbarum was explored.Under the conditions safe to SYAU-06,the physicochemical properties of different carriers and adjuvants were compared.The optimum formula for P.herbarum SYAU-06 water dispersible granules(WG)was determined as follows(by mass fraction):SYAU-06 fermentation mycelial cultures 15%,wetting agent BX 6%,dispersant NNO 4%,disintegrating agent ammonium sulfate 6%,binder polyethylene glycol(PEG 4000)4%,stabilizer calcium carbon 5%,carrier silica60%.The properties of P.herbarum SYAU-06 WG prepared in accordance with this formula were measured.The results showed that the content of SYAU-06 living mycelium was 2.55×10^8 cfu/g,the Phoma herbarum SYAU-06 isolated from diseased leaves of dayflower was expected to be a candidate of mycoherbicide,which could cause the death of dayflower by effective infection and was safe to most crops.In this study,the biocompatibility of different carriers and adjuvants with P.herbarum was explored.Under the conditions safe to SYAU-06,the physicochemical properties of different carriers and adjuvants were compared.The optimum formula for P.herbarum SYAU-06 water dispersible granules(WG)was determined as follows(by mass fraction):SYAU-06 fermentation mycelial cultures 15%,wetting agent BX 6%,dispersant NNO 4%,disintegrating agent ammonium sulfate 6%,binder polyethylene glycol(PEG 4000)4%,stabilizer calcium carbon 5%,carrier silica60%.The properties of P.herbarum SYAU-06 WG prepared in accordance with this formula were measured.The results showed that the content of SYAU-06 living mycelium was 2.55×108 cfu/g,the wetting time was 28.16 s,the disintegration time was 70.50 s,the suspension percentage was 88.90%,the pH value was 6.97,and the moisture content was 1.47%.All of the indicators of the sample were up to the standard.The field control efficacy of P.herbarum SYAU-06 WG on dayflowers in soybean field was determined by the foliage spraying method.The fresh weight control effect against dayflower 21 days after the application was 50.89%,55.97%,60.67%and 69.88%respectively at the formula dosage of 1305,1740,2175 and 3480 g/hm2.