A pilot study of pesticide reduction strategy in paddy fields at Liyang, Jiangsu Province

In order to reduce the use of pesticide in paddy field, improve rice quality and protect agricultural eco-environments, the feasibility of pesticide reduction strategy in paddy fields was tested at Liyang, Jiangsu Province. The analyzing control effects, pesticide dissipation, final residues and the yield were investigated. Conventional and reduction strategies were both evaluated. Three typical rice diseases and insect pests were chosen as examples. The prevention and control effects of these diseases and pests in paddy field, the residues of the pesticide in rice, and the yield were determined to evaluate the efficacy of these strategies. The results showed that the prevention and control effects of these three main diseases and pests using reduction strategy were better than or equal to the conventional strategy. The residues of pesticide in rice were all below the maximum residue limit in the experiments using both strategies. The yield was increased by 621 kg/hm² with the reduction strategy, but the differences were not significant. The total amount of pesticide used in the reduction strategy was 4 410 g/hm² (1 353 g a.i./hm²), and which in the conventional strategy was 6 885 g/hm² (1 553 g a.i./hm²). Hence, the reduction strategy not only prevented and controlled the diseases and pests effectively and  ensured the yield of rice, but also greatly reduced the input of pesticide and adjuvants in the environment, which reduced the harm to the environment.