果树重茬病成因及防治一、重茬病的成因：１．前茬果树的抑制作用。前茬果树的根系分泌物能抑制重茬果树根系的呼吸作用，严重时会使根系变褐死亡。同时，这些分泌物在前茬果树残留在土壤中的根、枝、叶等中含有的苦杏仁苷酶的作用下，会分解为苯甲酸、氢氰酸等有毒物质，... Reasons and prevention and treatment of fruit stubble disease First, the cause of stubble disease: 1. Pre-crop fruit tree inhibition. Root exudates of the former crop can restrain the respiration of the roots of the re-cropped trees and, in severe cases, brown the roots. At the same time, these secretions are decomposed into benzoic acid, hydrocyanic acid and other toxic substances under the action of amygdalin contained in the roots, branches and leaves of the former fruit tree residues in the soil.