戊唑醇不同防治时间对小麦赤霉病发生和籽粒中DON毒素积累的影响

摘要

为明确戊唑醇防治小麦赤霉病以及减少籽粒中DON(脱氧雪腐镰刀菌烯醇)毒素积累的关键时期,本研究于2015年和2016年在河南省焦作市温县进行了小麦花期前后不同时间喷施25％戊唑醇可湿性粉剂防治小麦赤霉病和减少籽粒中DON毒素积累的效果评价.试验结果表明:在2015年‘豫保1号’和2016年‘周麦18’上,齐穗期(Ⅰ-3,DAA=-1,Zadoks=59)、始花期(Ⅱ-1,DAA=0,Zadoks=61～64)、盛花末期(Ⅱ-2,DAA=1,Zadoks=69)、灌浆初期(Ⅲ-1,DAA=4,Zadoks=71)施药小麦赤霉病的病穗率、病情指数、病粒率和籽粒中DON毒素积累都显著减少(P＜0.05),以始花期或盛花末期施药防治效果最好;抽穗盛期(Ⅰ-1,DAA=-6,Zadoks=55)和齐穗期(Ⅰ、Ⅰ-2,DAA=-2、-4,Zadoks=59)施药在病穗率上都没有防治效果,而在病粒率上显著减少(P＜0.05);乳熟期(Ⅲ-2,DAA=10,Zadoks=73)施药在病穗率、病情指数和籽粒中DON毒素积累都没有防治效果.此外,齐穗期(Ⅰ、Ⅰ-2,DAA=-2或-3、-4,Zadoks-59)防治效果不稳定.2015年‘豫保1号’不施农药对照的病穗率高(85％)的条件下,齐穗期(Ⅰ,DAA=-2,Zadoks=59)喷药能显著降低病粒率和籽粒中DON毒素积累,并显著提高产量(P＜0.05),2016年‘豫保1号’不施农药对照的病穗率低(14.5％)的条件下齐穗期(Ⅰ,DAA=-3,Zadoks=59)喷药能显著降低病粒率(P＜0.05),但在籽粒中DON毒素积累和产量上没有防治效果,2016年‘周麦18’上齐穗期(Ⅰ-2,DAA=-4,Zadoks=59)喷药能显著降低病情指数和病粒率,但在籽粒中DON毒素积累和产量上没有防治效果.药剂不同时期施用对小麦赤霉病的防治效果受到年份和发病情况的影响.%In order to clarify the effect of tebuconazole application time on FHB and deoxynivalenol (DON) accumulation in wheat,field experiments were conducted in Wenxian County of Henan Province in 2015 and 2016.Treatments consisted of an untreated check and fungicide applications at early heading stage (Ⅰ-1,DAA=-6,Zadoks=55),heading stage (Ⅰ 、Ⅰ-2、Ⅰ-3,DAA=-2 or-3、-4、-1,Zadoks=59),early anthesis stage (Ⅱ-1,DAA=0,Zadoks =61 ～ 64),later anthesis stage (Ⅱ-2,DAA=1,Zadoks =69),early filling stage (Ⅲ-1,DAA=4,Zadoks-71),milking stage (Ⅲ-2,DAA=10,Zadoks=73).Field trials on‘ Yubao 1 ’ of 2015 and ‘ Zhoumai 18’ of 2016 showed that fungicide applications at heading stage (Ⅰ-3,DAA=-1,Zadoks=59),early anthesis stage (Ⅱ-1,DAA=0,Zadoks =61 ～ 64),later anthesis stage (Ⅱ-2,DAA =1,Zadoks =69) and early filling stage (Ⅲ-1,DAA=4,Zadoks =71) significantly reduced Fusarium head blight (FHB) incidence (Ⅰ),FHB disease index (D),percentage of diseased kernels (PDK) and deoxynivalenol concentration (DON) (P＜0.05).The most effective stage of the fungicide application was the early anthesis stage or later anthesis stage.Fungicide applications at early heading stage (Ⅰ-1,DAA=-6,Zadoks=55) and heading stage (Ⅰ 、Ⅰ-2,DAA=-2、-4,Zadoks=59) only significant reduced the percentage of diseased kernels (PDK) (P＜0.05).Fungicide applications at milking stage (Ⅲ-2,DAA=10,Zadoks=73) have no control effect.The control effect at heading stage (Ⅰ 、Ⅰ-2,DAA=-2 or -3、-4,Zadoks-59) is not stable.When the disease on ‘ Yubao 1’ occurred more seriously in 2015,fungicide applied at heading stage could reduce the PDK and mycotoxin concentration,and increased the yield (P＜0.05).However,when the disease occurred weakly on ‘Yubao 1’ in 2016,fungicide applied at heading stage only reduced the PDK (P＜0.05).Fungicide applied at heading stage (Ⅰ,DAA=-4,Zadoks=59) on ‘Zhoumai 18’ in 2016 had good control effect on the disease index and PDK (P＜0.05).The control efficiency of fungicides applied at different time was influenced by the disease severity in different years.