果树病虫害化学防治中存在的问题与对策在果树病虫的化学防治中，一些果园往往因盲目用药，乱打药造成防效低或不应有的损失。（１）打药不及时，不见病虫不打药，看见病虫大量发生了，再急急忙忙打药，以致延误了打药的最佳时期，以后虽连续用药，但收效甚微，所以应注意... Problems and countermeasures in chemical prevention and control of pests and diseases of fruit trees In the chemical control of pests and diseases of fruit trees, some orchards are often caused by blind medication, indiscriminate fight drugs cause low-effect or undue loss. (1) The fight against pesticides was not promptly observed. No pests and diseases were found. No pests and diseases were seen. A large number of pests and worms were seen. Hurrying to fight the drugs resulted in the delay of the best period for drug fight. Although the medicine was administered continuously afterwards, the effect was negligible. .