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杨树溃疡病经常在幼树干部形成大型溃疡斑,造成枝枯和死树。以胸径下病斑面积与树周面积的比值计算的发病程度(X_5)与胸径年生长量(Y_2)之间呈显著相关。通过回归建立了三个品种不同病情下的生长量模型: 美×5_(59):Y_2=-0.15406+118.52194/(102.9113+X_5~2) 加杨:Y_2=-0.4136+278.32113/(133.0115+X_5~2) 小×黑:Y_2=-0.08487+110.16972/(131.4548+X_5~2) 三个估算模型经数学检验合理;坐标曲线符合植物病理学原理,可作为该病病情分级和生长量损失估算的参考。
Poplar canker disease often forms large ulcer spots in the saplings of young trees, causing branching and dead trees. The incidence of disease (X_5) and the annual growth of breast diameter (Y_2) were significantly correlated with the ratio of lesion area to tree circumference at breast diameter. The regression model was established for the growth of three cultivars under different disease conditions. The results showed that: (1) ~ 2) Small × Black: Y_2 = -0.08487 + 110.16972 / (131.4548 + X_5 ~ 2) The three estimation models are mathematically verified; the coordinate curve is in line with the principles of plant pathology and can be used as an estimate of disease grade and growth loss reference.