What are the prevention and control measures of ornamental peach rot in winter and spring?

Peach trees are of great value and significance not only in agricultural production but also in garden appreciation. The flowers are in full bloom, and when the peach blossoms bloom in March, it can always cause a large number of people to come to watch. So what are the winter and spring control measures for ornamental peach rot?

I. symptoms and regularity of ornamental peach tree rot

Peach tree rot, also known as dry blight, mainly harms the main stem and main branches, causing bark rot and branch withered tree death.

When the disease spot first appeared, the bark bulged slightly and felt soft by pressing with your fingers. Continue to develop the disease part slightly sunken, the bark flow glue, the surface can see the rice grain big glue spot, the initial yellow and white, gradually become brown, brown to black. The diseased skin tissue under the glue spot is rotten, slightly swollen, moist, yellowish brown and smells of alcohol. The plaque expands longitudinally and soon reaches the xylem. In the later stage, the disease was dry and sunken, with dense black dots, from which yellowish-brown filamentous spore horns gushed out when the air was wet.

Peach tree rot mainly invades through wounds and lenticels, and the crack formed by frostbite is an important way for bacteria to invade. The orchard with poor soil, low-lying terrain, poor drainage and poor management has serious disease; it is rainy in autumn and the partial application of nitrogen fertilizer leads to overgrowth, poor cold resistance and serious disease.

2. prevention and control measures of ornamental peach tree rot

1. Strong trees to prevent diseases

(1) reasonable burden: thinning flowers and setting fruit according to the growth status of trees and the level of fertilization.

(2) increase the application of fertilizer and water: increase the application of organic fertilizer, phosphorus fertilizer, potassium fertilizer and trace element fertilizer, not too much nitrogen fertilizer.

(3) protecting leaves and promoting roots: timely control of diseases and insect pests that cause early defoliation of peach trees.

2. Pay attention to protecting the tree

The main results are as follows: (1) to avoid frost injury and daily burn: one is to prevent and cure the frost injury of peach branches: the trunk is painted white to reduce the temperature difference between day and night; the other is to prevent the tree trunk from freezing.

(2) to protect the wound: the larger saw blade should be cut flat, and then protected by varnish or Topurazine ointment, Smur921 antibacterial agent and so on. After the larger lesion is cured, it should be bridged and protected in time.

3. Timely treatment of plaque

(1) scraping bark: peach tree rot generally harms the superficial layer of the bark and scrapes off the disease spot before the peach tree germinates. After scraping off the diseased tissue, 70% methyl topiramate wettable powder and vegetable oil are evenly mixed according to the ratio of 1 to 2.5, and the disease part is smeared, which has a good effect on the cure of plaque, and can also be smeared with 843 rehabilitation agent solution to prevent scar recurrence.

(2) apply mud to prevent and cure: take fresh soil and mix well with clean water. the degree of moisture can be squeezed by hand to form a mass of mud that can adhere to the bark and then smear on the scar of fruit trees, with a thickness of 3-5 cm, surround it by 5 cm, and then wrap it tightly with plastic film to prevent water evaporation and mud falling off. After 1 year, the plastic film and mud were removed. The cure rate of this method is over 85%.

Pay attention to distinguish the dry rot of peach trees

Peach dry rot mostly occurs on the trunk and branches of older peach trees. At the beginning of the disease, the disease spot with stomata as the center protruding, dark brown, the surface is moist. There is yellow sticky glue under the cortex of the lesion.

The disease spot is long or irregular, generally limited to the cortex, but can go deep into the xylem on senescent trees. After that, the disease site gradually dried up and sunken, dark brown, and there were larger cracks.

In the later stage of the disease, a large number of fusiform or nearly round small black spots (constellation) grow on the surface of the disease spot, and sometimes several small black spots are dense together, exposed from the cracks in the bark, the size is generally 1mm to 8mm. The old tree that has been damaged for many years causes the tree to be extremely weak and seriously causes the whole side branch or the whole tree to die.