大豆豆荚炭疽病有效杀菌剂的筛选与防治适期研究

通过田间试验,筛选有效防治大豆豆荚炭疽病的杀菌剂,并对最佳防治时期进行研究。试验比较了8种杀菌剂对大豆豆荚炭疽病的防治效果,结果表明,防治该病害的有效杀菌剂以甲基托布津为首选,其次为施佳乐和好力克等。通过比较大豆始花期、盛花期和鼓粒期的防治效果,防效最好的是在始花期;在始花期、盛花期或鼓粒期的任何两个时期连防2次的防治效果显著好于只防1次的。在始花期与盛花期连续施药2次,防效超过95%。室内接种防治试验表明:当RH低于90%时,接种鼓粒期的豆荚喷与不喷甲基托布津都不发病;当RH为100%时,接种后24 h内喷甲基托布津,防效与对照不接菌无显著性差异,接种后48 h喷甲基托布津,防效显著低于对照不接菌。

Screening of effective fungicides and optimum period for controlling soybean pod anthracnose

The effective fungicides for controlling soybean pod anthracnose were screened and optimum period for it were studied by field experiment.The control effects of 8 fungicides on anthracnose of soybean pod were tested in field.The results showed that thiophanate-methyl should be used as the first choice fungicide to control soybean pod anthracnose,then pyrimethanil and tabuconazole etc.This experiment was conducted to compare the control effect with spraying thiophanate-methyl at the stage of flower beginning,flower flourish and seed filling of soybean,respectively.The optimal control growth stage was the stage of flower beginning.Applying fungicide two times at the stage of flower beginning,flower flourish or seed-filling of soybean,the control efficiency of soybean pods were significantly higher than applying fungicide one time at the same stage.Applying fungicide one time at the stage of flower beginning and flower flourish or seed-filling of soybean respectively,the control efficiency reached more than 95%.This experiment was conducted to control soybean anthracnose after inoculation at different relative humidity(RH).When RH was less than 90%,whether or not spray thiophanate-methyl,soybean anthracnose symptoms were not observed.When RH was 100%,spraying thiophanate-methyl 24 h after inoculation,the control efficiency showed no significant difference from that without inoculation.Spraying thiophanate-methyl 48 h after inoculation,the control efficiency was significantly lower than that without inoculation.