苹果绵蚜为害产量损失测定

苹果绵蚜为害苹果的树干、枝，新稍及根部，从中吸取大量营养，使寄主生长发育不良，产量降低。经测定苹果绵蚜发生群落数与造成的产量呈负相关，而与产量损失率成正相关，在苹果单株产量108．19～154．20kg，苹果绵蚜群落数±30～＞150个的情况下，小国光和青香蕉品种的产量损失率分别为4．10％～38．81％和7．5％～32．04％。

Test yield loss for the damage of Eriosoma lanigerum (Hausmann)

Eriosona lanigearum attacked apple trunks, branches, new tops and roots, caused apple trees to grow badly, and apple yield reduced becau se of absorbing a great untrient from hosts, yield loss was tested that it varied directly proportional to the community nambers, while the rate of yield loss was negatively correlative to it.Under conditions as follows: individal plant yield of apple range of 108.19-154.20kg and the community numbers range of ±30→ 150; the yield loss (the rate of loss) of rals and white winter perpetual was 6.3259.84kg (4.10-38.81%) and 8.21-34.66kg (7.59-32.04%).