Integrated control measures of pear diseases and insect pests

Pear is a kind of fruit with a lot of water, which tastes sweet and has a certain nutritional value. There are many varieties of pears, and the environmental requirements for planting are also different. if they are not managed properly in the planting process, they are vulnerable to diseases and insect pests. Let's take a look at the integrated prevention and control measures of pear diseases and insect pests.

I. common diseases and insect pests in pear trees

1. Black spot

Pear black spot is one of the main diseases in southern pear producing areas, which mainly harms pear leaves and fruits. The disease of young leaves is the earliest, needle-sized round black spots appear at the initial stage, and then gradually expand into round or irregular spots, the center of the spot is gray-white, the edge is dark brown, and black mold occurs on the surface of the spot when it is wet. Disease spots on the leaf surface can be connected into irregular large disease spots, and some cause early defoliation. The young fruit is susceptible, and the fruit surface produces round needle-sized black spots, which are enlarged into round or irregular spots, which are slightly sunken and cracked, with a black mold layer on the surface. When the disease is serious, the diseased fruit falls off early.

2. Pear rust

Leaf susceptibility: at the beginning, there are orange-yellow, glossy spots on the front of the leaves, and then gradually expand into orange-yellow spots in the middle of the circle, with yellowish-green halos on the outermost, and small yellow spots on the surface. When the weather is wet, it overflows with yellowish mucus, and when it dries, the small particles turn black. The tissue of the disease spot gradually thickens, the leaf is raised on the back, the front is slightly sunken, and the gray-yellow hair grows in the raised part.

3. Pear aphid

Pear aphid gathers adults and nymphs on buds, tender leaves and shoots to absorb pear juice. Nymphs concentrate on green buds in early spring and invade the buds with the opening of pear buds. After the pear bud spreads its leaves, it turns to the tender shoots and leaves to do harm. The injured leaves roll inward into a pine tube from both sides of the main vein. When the damage is serious, it causes fallen leaves, weakens the tree potential, and affects the fruit and flower bud differentiation of the same year.

4. Pear net bug

Adults and nymphs suck sap near the main vein on the back of the leaf. The affected leaf shows pale spots on the front and dark brown feces and secretions on the back of the leaf. When the damage was serious, the whole leaves were pale, and a large number of damaged leaves fell off in the early stage, resulting in secondary flowering of pear trees, affecting the yield of the current year and the second year.

II. Integrated control measures of pear diseases and insect pests

1. Prevention and control of black spot.

① cleans the garden strictly, strengthens the management of fertilizer and water, strengthens the tree potential, and avoids applying too much nitrogen fertilizer.

The diseased fruit, diseased leaves and diseased shoots were cut off in time during the growing season of ②, and burned centrally. Susceptible varieties were bagged.

③ pear trees were sprayed with 3-5 Bomedo stone-sulfur mixture before germination. After flowering, fungicides were sprayed every 15-20 days to protect the fruits according to the prevention and control of rainfall and other diseases. The medicament has 1RV 2VL 200 times Bordeaux liquid, 50% carbendazim wettable powder 500 times liquid or 65% Dysen zinc wettable powder 500 times solution.

2. Prevention and control of pear rust.

① is far away from cypress, cypress and other cypress plants, and all diseased branches are cut off in time before wind and rain.

② sprayed juniper and other transferred hosts with 430g/L tebuconazole suspension 3000 times in the first ten days of March or July for 1 or 2 times.

When ③ is used in early May, the following agents can be used: 1500 times of 10% difenoconazole water dispersible granules or 600 times of 80% Dysen zinc wettable powder. In order to treat pear black star, 12.5% uniconazole wettable powder 3000 times solution can be selected.

3. Control methods of pear aphid.

Early removal of the injured curling leaves, concentrated burning or deep burial. From early spring pear bud opening to sprouting and leaf expansion stage, 2.5% fenvalerate EC 3000 times or 20% permethrin EC 2000 times can be sprayed; in areas with conditions for stocking natural enemies, ladybugs and lacewings can be released to feed on aphids. Protect aphid flies, aphid-eating gadflies and other natural enemies.

4. Pear net bug

① completely uprooted weeds, dead branches and leaves in the orchard in winter, concentrated burning, and reduced the source of insects.

In September, ② wrapped the tree trunk with grass to trap the overwintering adults and deal with them together when clearing the garden.

Carbaryl poisonous soil was sprinkled on the ground from late March to early April to kill overwintering adults; 1000 times of 50% dichlorvos EC, 1000 times of 50% fenitrothion EC and 1000 times of 50% malathion emulsion were sprayed once in late April, early May and early June, respectively.