DPC对朱砂叶螨为害棉株的耐害补偿能力研究

Preliminary Studies on Tolerance Compensation Ability of the Cotton Plants Injuried by Spider Mite ( Tetranychus Cinnabarinus Boisduval ) with DPC

棉花蕾期受朱砂叶螨为害后，适量施用ＤＰＣ（缩节胺）可提高受害植株的耐害补偿能力，减少产量损失。其耐害补偿效应主要表现在棉株生长速率加快，缓解受害棉株株高、果枝数、结铃数受到的不良影响。其耐害补偿效应强弱取决于棉株长势水平和施用ＤＰＣ的剂量。朱砂叶螨为害棉花后具体施用ＤＰＣ的剂量需根据棉苗长势水平而定，以充分发挥ＤＰＣ增强受害棉株耐害补偿功能的作用。一般一类棉苗施用４次ＤＰＣ，总剂量为１４２．５ｇ／ｈｍ２，产量损失挽回率达１５．２％；二类棉苗施用４次ＤＰＣ，总剂量为１１２．５ｇ／ｈｍ２，产量损失挽回率达７．０４％；三类棉苗施用４次ＤＰＣ，总剂量为８２．５ｇ／ｈｍ２，产量损失挽回率达２％。根据上述试验研究结果，建立了不同ＤＰＣ剂量与各类棉苗长势水平和朱砂叶螨为害棉株后耐害补偿能力之间关系的理论模型。

Field investigation and plots trial indicated that application of DPC (N,N dimethyl peperidine chloride)on cotton in squaring stage injuried by spider mite ( Tetranychus Cinnabarinus Boisduval ) could increase its tolerance compensation ability and decrease the final yield loss.The effects of tolerance compensation mainly expressed in an increase of plants growth rate and relaxation of the side effect on plant height,fruit branch and boll formation.The effect on tolerence compensation depended on the cotton plants appearance and DPC dosage.Plots trial result showed that after being injuried by spider mite in squaring stage,the rate of yield loss decreased by 15 2% in high output cotton,7 04% in mid output cotton and 2% in low output cotton in use of DPC for 4 times while their total dosage of DPC were 142 5 g/hm 2,112 5 g/hm 2 and 82 5 g/hm 2, respectively.Based on the results above,the theoretical models of the relationship between DPC dosage and cotton apprearance and the ability of tolerance compensation after different cotton plant being injuried by spider mite were established.