Relationships between Neighborhood Comparison of Short-Rotation Poplar Plantations and Canker Disease Incidence

Since the occurrence of tree diseases has great correlation with the stand spatial structure,for poplar plantation composed with single tree species,to optimize the spatial structure,improve tree's potential growth,increase resistance of disease is the efficient way of prevention and treatment of poplar canker.In this paper,the correlation between canker occurrence of poplar plantation and neighborhood comparison of diameter at breast height,tree height and the size of tree crown was analyzed.The result shows that poplar 107,108 and DN113 in the same density,the occurrence of canker has significant negative correlation with neighborhood comparison of diameter at breast height,tree height and the size of tree crown.Comparative analysis of the same species with different densities was conducted in poplar plantation with planting space of 3 m×2 m,the disease severity index of poplar 107 has great negative correlation with neighborhood comparison of those indicators as well.And the correlation decreased with the declining of the density.When the planting space reaches to 3m×4m,the occurrence of canker would not be impact by individual dominance.