为有利于转Bt基因棉的普及和推广，现根据对转Bt基因抗虫棉（下简称Bt棉）棉田病虫害消长规律，提醒大面积种植Bt棉的农民应注意以下几个问题：一、必须保证Bt棉种内杀虫蛋白基因的含量及种子纯度若是种植回收繁殖代数较多，或因繁种田隔离带距离太近，种子纯度较低的种子，就 In order to facilitate the popularization and promotion of transgenic Bt cotton, farmers are advised to pay attention to the following questions on the basis of the growth and decline of pest and diseases of transgenic Bt cotton (hereinafter referred to as Bt cotton): First, they must Assurance Bt insecticidal insecticidal protein gene content and seed purity if the planting replanting more algebra or breeding farms because of the separation zone is too close to the seed purity of the seeds,