One of the reasons for blackening the leaves of pear is bacterial blight. Infects the plant through wounds and cracks on shoots, leaves, stomata, nectaries of flowers. The patient pear young leaves start to blacken from the edge to the center, in addition to darken the upper ends of the shoots. Spreading through the vessels with the movement of juice, bacterial blight strikes the plant from the inside.
To combat the disease during flowering fivefold treat all plants in the garden with a solution of copper sulfate in the lime milk. The solution should be neutral (pH=7,0), as the excess sulfate may damage the leaves, and the excess lime to reduce the healing properties of the liquid.
To prevent fire blight be sure to disinfect all tools and planting containers for water.
If infection has occurred, cut off the branches at a distance of twenty inches from the affected area, trimming from burn. Trees which cannot be cured, wikicite and burn it on the spot.
Blacken the leaves on the pear, if it attacked the ordinary sucker – small winged insect black and brown, which can fly and jump. Larvae and adults suck the SAP from young shoots and greens evoke the shedding of the ovaries and the withering away of the flowers, crushing the leaves.
A good tool to combat sucker – tobacco broth, which must be mixed with a thick soapy foam.
Honeydew that the larvae secrete, spread out and glue the flower stalks, the inner part of the drop-down buds and young leaves at the tips of shoots. These secretions begin to develop black mushrooms, of which the leaves, branches and fruits become dirty with a black sticky residue.
To cope with the pest, treat bag 60oC water, it must be done before Bud break. During the opening of the buds and to flowering, the tree needs to be sprayed a solution of Malathion (0.3 percent). During the growing season spray the plant extract of garlic, tansy or onion peel, before doing this it should be mixed with wood ashes. To destroy the adults use a solution of trichlormethane (0,2-0,3%).
Another reason for the Browning leaves of the pear is the humidity. Excessive dryness of the herbs may turn black even in trees that are regularly and abundantly watered. In this case, in addition to regular watering, enter the periodic spraying plants with plain water.