Diseases of Fruit Plantation Medicinal and Aromatic Crops

Pear decline

Early or premature foliar discoloration is a general symptoms of this disease.
Casual organism: Phytoplasma like organism (PLO's)
Symptoms

• Pear decline is characterized by two phases: quick decline and slow decline. Trees may wilt, scorch, and die in a few weeks or lose vigor over several seasons during which foliage gets sparse with little or no terminal growth and leaf size reduced.
• An abnormal early red leaf coloration has been observed generally on infected trees. Examining the graft union reveals a brown line on the cambial face of the phloem tissue. (Use a pocket knife to expose the cambium.)


Management
Cultural control
• Use resistant or tolerant rootstocks.
• Use the best orchard management practices, including the best possible insect and disease control, irrigation, drainage, fertilization, and pruning.
• Control pear psylla.
• When grafting Asian pear trees over to European (P. communis) cultivars, graft below the union of the Asian pear with its rootstock to avoid creating a highly decline-susceptible tree.