防治猕猴桃溃疡病涂抹剂的研制及其应用

Development and application of paints for controlling kiwifruit canker

由丁香假单胞菌猕猴桃致病变种Pseudomonas syringae pv. actinidiae (Psa)引起的猕猴桃溃疡病是猕猴桃产业上的毁灭性病害,生产中常施用水基型制剂进行防治,但因其附着性低且不易成膜保护树体,防治效果并不理想。为研制可有效防治猕猴桃溃疡病的新技术措施,本研究通过对不同填料和增稠剂进行筛选,并将两者混合后得到成膜助剂,再加入优化后的渗透剂制备得到基础涂抹剂(涂抹剂基^(#)),对其成膜性、在树体上的附着性及耐雨水冲刷能力等性能指标进行了评价;向涂抹剂基^(#)中分别加入复配杀菌剂组合1^(#)(四霉素与戊唑醇质量比2:1)和组合2^(#)(四霉素与噻霉酮质量比5:1),制得涂抹剂1^(#)与涂抹剂2^(#);采用滤纸片法测定了涂抹剂基^(#)、涂抹剂1^(#)、涂抹剂2^(#)及所对应的杀菌剂组合对猕猴桃溃疡病菌的室内抑制活性,并通过田间试验验证了其对猕猴桃溃疡病的防治效果。结果表明:配方筛选所得最适填料为纳米膨润土,最适增稠剂为聚乙烯醇2488,将两者分别按质量分数3.00%与10.00%混合得到成膜助剂,再加入质量分数为1.60%的最适渗透剂奇功后制得涂抹剂基^(#),该涂抹剂基^(#)为乳白色粘稠液体,呈弱酸性,具有高黏度、高延展性、高拉丝度及强树体附着性,在玻璃板上涂抹123 min后可形成有韧性的薄膜,所得膜的固含量流失率为6.77%,耐雨水冲刷能力强。室内抑菌活性测定表明,涂抹剂基^(#)对猕猴桃溃疡病菌无抑制活性,涂抹剂1^(#)与涂抹剂2^(#)的抑菌活性明显高于其所对应的杀菌剂组合单独使用;田间试验结果表明,涂抹剂基^(#)对猕猴桃溃疡病的防效在30%以上,而涂抹剂1^(#)与涂抹剂2^(#)的防效均可达65%以上,且显著高于所对应的杀菌剂组合单独使用。本研究所制备的涂抹剂对猕猴桃溃疡病具有较好的防治效果,具有一定的开发应用价值,同时可为田间病虫害防治提供一种新途径。

The kiwifruit canker caused by Pseudomonas syringae pv.actinidiae(Psa)is a devastating disease in the kiwifruit industry.In field production,the water-based pesticide is often used to control the disease,but the control efficacy is poor because of its low adhesion and difficulty in forming films to protect plants.In order to develop a new technical measure to control kiwifruit canker,different fillers and thickeners were screened and mixed to obtain a film-forming assistant.Subsequently,the optimized penetrant was added into the mixture for preparing the basic paint(paint base^(#)),and its filmforming ability,tree adhesion,resistance to rainwater erosion and other properties were evaluated.The paint 1^(#)and paint 2^(#)were obtained by adding antibacterial combination 1^(#)(tetracycin and tebuconazole at the mass ratio of 2:1)and antibacterial combination 2^(#)(tetracycin and benziothiazolinone at the mass ratio of 5:1)into paint base^(#),respectively.In vitro toxicities of paints base^(#),1^(#),2^(#)and their corresponding antibacterial combinations against Psa were determined by filter paper method,and their control efficacy was verified by field experiment.The results of formula screening showed that the optimal filler is nano bentonite and the optimal thickener is polyvinyl alcohol 2488.The film-forming assistant was obtained by mixing 3.00%(mass fraction,the rests were the same)nano bentonite and 10.00%polyvinyl alcohol 2488,and then the paint base^(#)was prepared by adding 1.60%of the optimal penetrant qigong into the paint.The paint base^(#)was a milky white viscous liquid with weak acidity,high viscosity,high ductility,high drawing degree and strong tree adhesion.After applying it on the glass plate for 123 minutes,a ductile film can be formed with a solid content loss rate of 6.77%,indicating that the film had strong resistance to rainwater erosion.In vitro toxicity results showed that paint base^(#)had no antibacterial activity against Psa,while the antibacterial activities of paint 1^(#)and paint 2^(#)were significantly higher than that of the corresponding single antibacterial combinations.The field trials showed that the control efficacy of paint base^(#)on kiwifruit canker was more than 30%,and the control efficacies of paint 1^(#)and paint 2^(#)both reached more than 65%,which were significantly higher than that of the corresponding single antibacterial combinations.The paints prepared in this study displayed good effects on controlling kiwifruit canker,which showed high application values and may be a new way for disease and pest management in the field.