What causes root rot in fruit trees?

When chemical fertilizers dominate long-term, fruit trees are the first to suffer. Long-term application of chemical fertilizers such as diammonium phosphate, urea, potassium sulfate, compound fertilizer and mixed fertilizer destroys the soil and causes many disastrous problems for fruit trees.

Large amounts of unfermented and undecomposed farmyard manure are applied. Large amounts of unfermented and undecomposed human, livestock and poultry manure are applied directly into the orchard soil, and the large amounts of pathogens, insect pests, salt and so on that they carry will cause serious damage to the root system, and in severe cases will cause root rot and tree death. In order to save labor and effort, hole application and trench application are used, with few and small trenches (holes) dug, and the fertilizer is filled into the holes and trenches and covered with soil; burning the roots is also a common phenomenon.

Giving up soil management for a long time intensifies soil compaction. If the orchard is not dug or loosened for a long time, and weed control in spring and summer relies entirely on herbicides, only the weeds are killed, but the soil aeration cannot be improved. As a result, the topsoil remains severely compacted for a long time.

The nutrients stored in the tree body are seriously insufficient. Orchard households that normally strengthen management, spray to protect leaves, apply topdressing in summer, and apply base fertilizer in autumn, with all management in place, maintain sufficient stored nutrients in the tree body and have a very high fruit-setting rate. Orchard households that give up management do not apply topdressing in summer or base fertilizer in autumn, so the tree body's nutrients are seriously deficient, causing canker to run rampant, and many fruit trees are dug out.

Excessive use of herbicides. Using glyphosate for weed control multiple times within a year, if operated improperly, can seep into the soil and damage the underground root system of fruit trees, thereby causing poor nutrition in the aboveground part, yellowing leaves, and weakened tree vigor, affecting the fruit trees' sprouting, flowering and fruit setting the following year. Using glyphosate in orchards can also easily cause zinc deficiency in the soil. The zinc deficiency symptoms caused by abuse of glyphosate occur in both apple trees and peach trees, and in severe cases have already endangered the life of the tree body.