不同玉米品种对玉米主要病虫害的抗性及大喇叭口期喷药对大斑病的田间防效

旨在明确玉米品种对玉米主要病虫害的抗性及药剂防治对玉米大斑病的田间防效。通过田间调查,分析27个玉米品种对玉米大斑病和玉米螟的抗性;通过玉米大喇叭口期整株喷雾,研究不同药剂处理对玉米大斑病的田间防治效果。结果表明,玉米灌浆中期,供试27个玉米品种的大斑病发病株率为58.33%～100%,平均91.42%;发病级别2.33～6.97,平均4.51。玉米蜡熟期所有供试玉米品种的大斑病发病株率均为100%,平均发病级别6.89;玉米螟危害的被害株率23.33%～71.67%,平均45.74%;百株虫量20.00～88.33,平均51.94。大喇叭口期整株喷雾,供试11个药剂处理对玉米大斑病的田间防治效果均较低,其中最低0%,最高10.57%,平均仅为5.37%。由此可见,不同玉米品种对大斑病和玉米螟的抗性差异很大,且供试27个品种不同时期对玉米大斑病的抗性强弱排序不同;大喇叭口期药剂整株喷雾防治玉米大斑病,供试11个药剂处理的田间防效均不理想,尚需进一步深入研究。

Resistance of Different Maize Varieties to Major Maize Diseases and Pests and Control Effect of Fungicide Spraying on Maize Blight in Flare Opening Period

The objective of this study isto clarify the resistance of maize varieties to major plant diseases and pest insects,and the field control effect of fungicide on maize blight.It is of great practical significance toselect maize varieties with high yield,good quality and strong resistance to plant diseases and pest insects,finally,the rampant occurrence of these pests is controlled.The resistance of 27 maize varieties tomaize blight and Asian maize borer Ostrinia furnacalis were analyzed by field investigation,meanwhile,the control effect of different fungicide treatmentson maize blight in the big flare stage was also studied.The results showed that the incidence rates of 27 tested maize varieties was 58.33%-100% with the mean of 91.42% in the middle of maize filling stage.The disease degrees ranged from 2.33 to 6.97 with the average disease degrees of 4.51.In the dough stage,the incidence rates of all selected varieties were 100%with an average disease degree of 6.89.The rate of plants damaged by maize borer was 23.33%-71.67% with an average damage rate of 45.74%.The number of maize borers on every 100 maize plants was 20.00-88.33 with the average number of 51.94.When different fungicides were sprayed at the big flare stage,the control effects of all the 11 treatments on maize blight were very low,the lowest,highest and average efficiency were 0%,10.57% and 5.37%,respectively.The results showed that there were significant differences in the resistances to maize blight and maize borers of the 27 maize varieties.The order of resistance levels of 27 varieties to maize blight was divergent at different growth stages.The control effects of fungicides were unsatis factory when the whole plants were sprayed atthe big flare stage,but the reasons were still needed to study further.