Pear decline
Pear decline is caused by a microorganism called a mycoplasma, which is spread by pear
psylla. Trees
with pear decline have poor shoot and spur growth, dieback of shoots, upper rolling of leaves, reduced
leaf and fruit size, and premature leaf drop. Sudden tree collapse can result from tissue damage at the
graft union on highly susceptible rootstocks, but slow decline is more common.
Life cycle
Solutions
Some tolerant rootstocks may be available. To keep the disease in remission on susceptible rootstocks,
control pear psylla and maintain trees in good vigor; reduce stress caused by inadequate irrigation,
nutrient deficiency, weed competition, and lack of pruning. Consider replacing trees on susceptible rootstocks
with resistant ones. | 
Rolling
and discoloration of leaves
|
