Prevention and control of diseases and insect pests of peach trees in early spring

With the gradual warming of the weather in early spring, all kinds of peach diseases and insect pests began to recover, breed and multiply. The prevention and control of peach diseases and insect pests in early spring can effectively control the occurrence and spread of peach diseases and reduce the occurrence base of peach pests. In this paper, the occurrence and damage of main peach diseases and insect pests and their control suggestions in early spring are briefly introduced as follows:

1. Peach anthracnose

Occurrence and harm: it is the main fungal disease of peach trees in this area. The mycelium overwintered on the diseased branches and stiff fruits, produced spores in the early spring of the next year, infected the fruiting branches, and then spread to the flowers and fruits one after another, aggravating the damage. In severe cases, a large number of fruit branches withered and the fruits rotted. There are three disease processes in a year in Shanghai, which are found to occur on the fruiting branches from mid-March to early April, on young fruits in the first and middle of May, and in the fruit ripening stage in June and July. The young fruit stage suffered the most in the whole year.

Control methods in early spring: ⑴ cut off the withered branches, stiff fruits and stumps, or the first diseased branches before and after bud germination to flowering to eliminate the source of overwintering disease and prevent re-infection; ⑵ strengthen drainage, increase phosphorus and potassium fertilizer, strengthen tree potential, and avoid leaving branches too dense and too long; spray 1 ∶ 1 ∶ Bordeaux solution 1-2 times when peach buds germinate (prohibited after leaf expansion).

2. Peach bacterial perforation

Occurrence and harm: it is a bacterial disease, overwintering on the diseased shoot, overflowing bacterial pus in the diseased part in the following spring, and transmitted by wind, rain and insects. Invaded by stomata, lenticels, etc. It usually occurs after leaf spreading in the middle of April. the annual peak is the Meiyu season from May to June and the typhoon season from August to September. It mainly harms the leaves and fruits of peach trees, resulting in leaf perforation and fruit cracking.

The method of prevention and control in early spring is the same as peach anthracnose.

3. Peach root cancer

Occurrence and harm: it is a bacterial disease, which mainly damages the root and root neck, forming tumors, resulting in serious poor growth of peach trees, short plants, poor fruit quality, and serious death of the whole plant. The pathogenic bacteria live in cancer tissue or soil and can be spread by Rain Water runoff or irrigation water and diseased seedlings and invade through wounds.

Prevention and control methods in early spring: ⑴ strengthened soil management, reasonable fertilization, improved soil, enhanced tree potential; ⑵ strengthened orchard inspection, dug up the topsoil of suspected diseased plants, scraped off or thoroughly scraped the roots with KG84 after discovering the disease, and dug out and burned serious plants.

4. Peach gum disease

Occurrence and harm: it is a physiological disease of peach trees, which mainly occurs on the branches, and glue flow can also occur on the new shoots, leaves and fruits, resulting in rough bark, cracking and not easy to heal in the diseased branches. When the gum flow is serious, the tree is weak, and it is easy to become the spawning place of peach longicorn beetles and accelerate the death of peach trees. The phenomenon of gum flow can occur during the whole growth period of peach trees, but it occurs most frequently in rainy seasons such as Meiyu and Taifeng period, and more frequently in old trees and weak trees.

The prevention and control methods in early spring should strengthen the comprehensive management, promote the normal growth and development of the tree, and enhance the tree potential.

5. Mulberry white scale

Occurrence and harm: also known as mulberry shield shell insect and peach white shell insect, is an important pest of peach trees. The fertilized female adults overwintered on the branches, and there were three generations a year in Shanghai. The overwintering female began to lay eggs in mid-April, and the occurrence periods of the three generations of nymphs were in the first and middle of May, July and September, respectively. Female adults and nymphs harm the new shoots, branches and fruits of peach trees, seriously weakening the tree, greatly reducing fruit yield and varieties, and even withering the whole tree.

Control method in early spring: spray Baume 5 degree stone sulfur mixture or 100 times oil emulsion before sprouting to eliminate overwintering female adults. When the insect body is dense into a piece, it can be removed with a hard brush before spraying to facilitate the penetration of the liquid.

6. Red-necked longicorn beetles

Occurrence and harm: commonly known as saw tree Lang, is an important peach pest. The larvae overwintered in the injured parts of the branches, usually completing a generation every 3 years. The mature larvae pupate in May, the adults occur in mid-late June, lay eggs from late June to early July, and the larvae begin to overwintering in late October. The larvae eat the cortex and xylem of the branches of peach trees, which weakens the tree potential and shortens its life. In severe cases, peach trees die.

Prevention and control method in early spring: after finding the injured site according to the branches and ground decay and insect dung, stab the larvae with iron wire.