[Effect of soil fertility on chestnut stem diseases]

Studies on the relationship between soil fertility and chestnut stem disease showed that in soil physical factors, the disease index in the chestnut orchards with clay soil and stone soil was higher than that with loam, sand loam and yellow-brown loam soil. It was increased with the increasing soil bulk density, and decreased with increasing soil depths. In soil chemical factors, the disease index negatively associated with the contents of organic matter and available phosphorus, and not with total nitrogen, K and pH value. Based on the above factors and stepwise regression, five factors such as soil depth, bulk density, clay soil, organic matter and available phosphorus were regarded as important to the disease, and a linear multiple regression model that predicts the development level of the diseases was derived, which could assist in manageming the particular stand against chestnut stem diseases in Anhui Province.