Department of Agro-biotechnology, China Agricultural University, Beijing, China.
Environ Monit Assess. 2011 Feb;173(1-4):985-94. doi: 10.1007/s10661-010-1439-y. Epub 2010 May 2.
In the past, scientific research has predicted a decrease in the effectiveness of Bt cotton due to the rise of secondary and other sucking pests. It is suspected that once the primary pest is brought under control, secondary pests have a chance to emerge due to the lower pesticide applications in Bt cotton cultivars. Studies on this phenomenon are scarce. This article furnishes empirical evidence that farmers in China perceive a substantial increase in secondary pests after the introduction of Bt cotton. The research is based on a survey of 1,000 randomly selected farm households in five provinces in China. We found that the reduction in pesticide use in Bt cotton cultivars is significantly lower than that reported in research elsewhere. This is consistent with the hypothesis suggested by recent studies that more pesticide sprayings are needed over time to control emerging secondary pests, such as aphids, spider mites, and lygus bugs. Apart from farmers' perceptions of secondary pests, we also assessed their basic knowledge of Bt cotton and their perceptions of Bt cotton in terms of its strengths and shortcomings (e.g., effectiveness, productivity, price, and pesticide use) in comparison with non-transgenic cotton.
过去，科学研究曾预测，由于次要害虫和其他吸食性害虫的增加，Bt 棉花的效果会降低。人们怀疑，一旦主要害虫得到控制，由于 Bt 棉花品种中农药用量减少，次要害虫就有机会出现。关于这一现象的研究很少。本文提供了经验证据，表明中国农民在引入 Bt 棉花后，明显感觉到次要害虫的增加。这项研究基于对中国五个省份的 1000 个随机选择的农户进行的调查。我们发现，Bt 棉花品种中农药使用量的减少明显低于其他研究报告的水平。这与最近的研究提出的假设一致，即随着时间的推移，需要进行更多的农药喷雾来控制新出现的次要害虫，如蚜虫、红蜘蛛和盲蝽。除了农民对次要害虫的看法外，我们还评估了他们对 Bt 棉花的基本认识，以及他们对 Bt 棉花在有效性、生产力、价格和农药使用方面相对于非转基因棉花的优缺点的看法。
