摘要
采用二次回归通用旋转组合设计，探讨了１９８７年晚稻“圭巴”品种小区笼罩条件下稻纵卷叶螟、褐稻虱及其混合种群为害损失率和经济阈值．稻纵卷叶螟经济阈值因生育期不同而异，每百蔸幼虫分蘖期为１２１．３头，抽穗期为１３１．２头．褐稻虱抽穗期的经济阈值为百蔸４９４头若虫．本文提出了抽穗期稻纵卷叶螟、褐稻虱混合为害的产量损失率模型，在生产实践中，可直接利用此模型进行防治决策．
The injurious loss caused by Cnaphalocrocis medinalis,Nilaparvata lugensstal,their mixed population damage and their economic threshold(ET)were studied by regres-sion rotational combinational design in cage condition in this paper.The results were as fol- lows:The ET of rice leaffolder varies with different rice growth stages,its ET is 121.3 sec-ond instar larvae per 100 plants at tillering stage,131.21 second instar larvae per 100 plantsat initial heading stage.The ET of brown planthopper is 494 fourth instar nymph at rice ini-tial heading stage.The ET of mixed population can be determined according to the regressiveequation.
关键词
稻纵卷叶螟
稻飞虱
经济阈值
Cnaphalocrocis medinalis rice leaf rollers
Nilaparvata lugens rice plant hop-pers
pest control methods/pest mixed population
economic threshold
