梨黑星病一直是陕西梨产区的主要病害。自1998年暴发以来,梨农始终将该病害的防治当作头等大事来抓,有的已经形成一种习惯,每年都要定期喷药防治。从减少农药残留,保护环境安全,依据实情防治,节支、增效的角度考虑,每年用5～7次药剂防治一种病害,是很不科学的。为了科学指导防 Pear scab has been the main disease in Shaanxi pear producing areas. Since the outbreak in 1998, peasants have always regarded the prevention and treatment of this disease as a top priority. Some have formed a habit of spraying and controlling regularly every year. From the perspective of reducing pesticide residues, protecting the environment and preventing and controlling diseases according to the actual conditions, saving costs and improving efficiency, it is unscientific to use 5 to 7 times of pesticides to prevent and treat a disease every year. To guide scientific defense