陕西套袋苹果黑点病发生规律研究

研究了陕西果产区套袋苹果黑点病发生规律。结果表明:套袋苹果黑点病在7月初发病,8月上、中旬病情迅速加重,8月底达到高峰;低海拔地区果园发病率显著高于高海拔地区;树冠中、下部和内膛发病率高于上部和外围;使用不同种类的果袋,苹果发病率不同。在洛川,苹果黑点病发病率较低的果袋为:小林袋、三秦袋和精工袋,杨陵为:兆丰袋、精工袋和小林袋。加大透气孔和扎死透气孔均对黑点病的发生有显著影响;去花萼后套袋发病率显著低于对照;套袋前一天喷8 000倍杜帮福星时,发病率显著低于其他药剂。

Occurrencs of Black-dot Disease on Bagged Apple in Shaanxi Province

Researches on black-dot disease of bagged apple in Shaanxi showed that the disease started in early July,become serious in the early and middle of August and reached peak by the end of August.The disease in apple orchards at high elevation was more serious than that at lower elevation.In the middle,bottom and inside crown of the apple trees,the disease was more serious than that at the top and outside.There were differences among apples treated with differenr bags,the disease occurrence rate in apples treated with Xiaolin,Sanqin and Jinggong bags was lower in Luochuan,while that with Zhaofeng,Jinggong and Xiaolin bags lower in Yangling.Enlarging and closing the vent of bags decreased the rate in Yangling.Getting rid of calyx decreased the occurrence rate in Yangling and Luochuan.After spraying 800 times Lazole one day the occurrence rate in bagged apples was lower than that treated with insecticides.Factors influencing the disease occurrence,prevention and control are discussed.