1.落果原因 北斗采前落果的主要原因是霉心病,其次是生理落果。从北斗的植物学特性看,果实花萼筒与心室相通,萼筒较大,谢花后很多病菌孢子通过萼筒进入果心,在果心引起发病,形成霉心病。有近10种病菌可使北斗苹果患霉心病,主要是细交链孢及粉红单端孢两种病菌,患病后 1. The reasons for the fall fruit Beidou mining the main reason is falling before the mold heart disease, followed by physiological drop fruit. From the botanical characteristics of Beidou, the fruit of the calyx tube and the ventricular communicating, calyx tube larger, thank a lot of bacteria after germination spore through the calyx tube into the heart, the fruit heart cause disease, the formation of mildew heart disease. There are nearly 10 kinds of bacteria can make Beidou apple mold heart disease, mainly thin Alternaria and pink single-tipped two bacteria, after the illness