Effects Of Main Cultivation Measures On Helicoverpa Armigera In Cotton Field

Helicoverpa armigera (Hübner) is one of the main insect pests of the cotton production in Xinjiang province. In recent years, cultivation way of cotton has had the very big change in Xinjiang, and the occurrence and damage of Heliothis avmigera are becoming seriously, which is restricting the cotton production. Exploring the relationship between the occurrence and hazards of Helicoverpa armigera(Hübner) with the local cotton cultivation measures and puting forward a reasonable and effective control strategy has a very important practical significance to cotton production in XinjiangIn this paper, we studied the effects of various cotton irrigation methods, different amount of nitrogen application, different pharmaceutical control of different cotton varieties and autumn plowing winter irrigation on Helicoverpa armigera by indoor and field experiments, the main results are as follows:fluence of different irrigation ways to growth and harm of Heliothis avmigera (Hübner): Net interior inoculating insect pest tests showed that,when compared with furrow irrigation, the number of cotton bollworm eggs layed on cotton plants of irrigation field was 3.76 times than that of furrow field, cotton bollworm eggs hatching increased 45.13%, larval survival was higher, the rate of buds and bolls enchanced 35.30%, the rate of pupae was 6.09 times more than that in furrow irrigationInfluence of chemical control to the growth and harm of Heliothis avmigera(Hübner):by adopting the method of inoculation and breeding,the effects of the different of chemical control medicament,mepiquat chloride (PIX) and Paclobutrazol(PP333) on development of Helicoverpa armigera (Hübner)and the damage to cotton plant were studyied. Comparing to CK, the number of cotton bollworm eggs layed on cotton plants decreased 29.34% by spraying chemical control medicament; HatchIing of cotton bollworm eggs was delayed and eggs hatchability was decreased 18.17%～36.36% by using medicament;the duration of larva development was shorten 0.1～1.7d; death rate was increased 2.0%～28.6%; the duration of pupae development was delayed 0.3～3.0d.There was different effects of PIX and PP333 on cotton bellworm in different development phases.The restrain action of PP333 on hatch of cotton bollworm eggs was better than PIX, but the effects of PIX on larval growth and oviposition preference were stronger than PP333. There was difference in effects of PIX and PP333 on damage of cotton bellworm, but the damage of lower instar larva was lightened.Influence of different nitrogen ferlization levels to development of Helicoverpa armigera(Hübner): Field and room experiments were conducted to assess the effects of nitrogen ferlization levels (75,225,375 5kg/hm²) on development of cotton bollworm. Inoculating and breeding results showed that the number of eggs of cotton bellworm is lowest in cotton field ferlizated 225kg·hm^-2 . It was not big that effects of amount of nitrogen ferlization on survival rate of early-instar larvae, with amount of nitrogen ferlization on increased, survival rate of later-instar larvae of cotton bollworm have had a upward trend, However, in all the larval stages, in the middle level of nitrogen, the survival rate and pupation rate of the cotton bollworm fed are lowest; the development duration of larvae and pupae increased with the nitrogen to extend, General of the results, midium level of nitrogen ferlization was more conducive to the integrated control of cotton bollworm.Influence of different varieties of cotton to Helicoverpa armigera development and the damage : In Shihezi region ,12 local cotton varieties resistance to bollworm was conducted a comprehensive evaluation by indoor and outdoor experiments, The reselt showed that the Biaoza A1 and Xingpaotai1 was resistant varieties, Xinluzao 36, Xinluzao 33 and Xinluzao 21 were for the susceptible varieties, medium resistant cotton varieties, resistance to the cotton bollworm of Zhongmian 42 had consistent performance indoor and outdoor, damaged was relatively.Impact of autumn plowing winter irrigation to cotton bollworm overwintering: The results showed that Helicoverpa armigera(Hübner) pupae overwintering mortality rate was 90.0～92.5% in the land winter irrigated autumn plowed , in the land plowed, mortality rate was 70.8～75.0%, in the land irrigated it was 80.0～84.6%, plots of non-cultivated non-irrigated was 50.0～70.4%...