People often say that "cherries are delicious and difficult to plant", and large cherries, as a kind of sweet cherries imported from the country, are highly sought after by people because of their large size and delicious taste. Compared with china's traditional Chinese small cherries, large cherries seem to be more delicate and difficult to manage.
During this time, I have been busy in the orchard, pruning and shaping the fruit trees. In the process of pruning the big cherries, I found that there were individual branches that withered, and in severe cases even dried up. Next, I will give you an analysis of the "culprit" that causes the new shoots to wither, and how to deal with it in production, for your reference.
<h1 class= "pgc-h-arrow-right" > the symptoms and harms of new and slightly dried large cherries</h1>
We know that the aboveground part of the fruit tree grows upward and phototropic, and the new growth of the branches plays a very important role in the growth process of the whole fruit tree. Large cherries are no exception, especially in the management of the young tree stage, we mainly shape the tree type and expand the canopy, and the gibberellose plant hormone produced by the growth point of the new shoots can stimulate the root system to absorb more water and fertilizer, and supply the leaves to produce organic nutrients through photosynthesis to meet the growth needs of the large cherries.
There is worm dung on top of the new slightly wilted
Once the new shoots are damaged, the gibberellosis substance is reduced, which is bound to affect the normal growth of the entire fruit tree. In the process of shaping large cherries, I found that individual new shoots grew abnormally and showed symptoms of wilting.
The culprit who endangers the new shoots
At the top of the new shoots, there is obviously a distribution of insect feces, which is harmed by insects. Tear the new shoots from the top, and because the larvae are just beginning to become harmful, they are only about 2 cm into the new shoots. This white bug is called a heart-eating worm, as the name suggests, it specializes in eating the new branches of various fruit trees such as large cherries, and next, I will tell you about the life habits of heart-eating insects and how to control them in production.
<h1 class= "pgc-h-arrow-right" > culprit's habits</h1>
There are many types of heart-eating insects, which are divided into pear small heartworms, peach small heartworms, pear large heartworms, plum small heartworms, peach borer borers and so on. Among them, the more common are pear small heartworms and peach small heartworms, which not only harm the new shoots of fruit trees, but also cause great harm to fruits in the middle and late stages.
Pear small heartworm three forms
The main cause of harm to the new shoots of large cherries is the pear small heartworm, which is a genus of small heartworms in the family Curly moth family. The adult body is about 0.6 cm long, the whole body is gray-brown or gray-black, the head has antennae, the forewings are gray-black and the hindwings are tea-brown, and the larvae are about 1.2 cm long and the body is pale red.
Pear small heartworm adults
Pear small heartworms can occur three to five generations a year, of which the egg stage varies from 4-10 days according to the temperature, the larval stage is 10-15 days, the pupal stage is 7-15 days, the adult lifespan is about 15 days, and the complete generation is about 35 days.
After overwintering in cocoons, the old mature larvae begin to pupate in March of the following year, feather and lay eggs in April, and each female can lay more than 50-100 eggs, with eggs on the back of the leaves. The first generation of larvae mostly begin to hatch in early May, burrowing in from the petiole or calyx of the young shoots of fruit trees, and the early stage is excreted with insect feces, and in the later stages, no insect feces appear. The second generation of eggs continues to harm the young shoots of fruit trees in June and July.
larvae
Pear small heartworms have the characteristics of transferring hosts, which can be transferred between fruit trees such as large cherry, peach tree, and pear tree. The first and second generations are mainly harmful to peach trees and large cherry new shoots, and usually in July, the third and fourth generations of larvae mainly harm the fruits of pear trees, peach trees, apples and other fruit trees. Adults hide in foliage or weeds during the day and begin to move before dark, with strong phototropism and flavor.
< h1 class = "pgc-h-arrow-right" > how to control in production</h1>
Heart-eating insects reproduce faster, and if left unchecked, first- and second-generation larvae are particularly harmful to the new shoots of large cherries. Moreover, large cherries can not be bagged, may and June is the time when large cherries are ripe, and it is not appropriate to use pesticides for chemical control. Therefore, in production, we can usually take the following method.
1. Prevention and control at the young stage
Large cherries do not have fruit in their young stage, and we can use medicinal chemical control. Before the first generation of larvae hatch at the end of April and before mid-June, spray 2.5% cypermethrin emulsion 2500 times liquid or 10% cypermethrin 2000 times liquid each. If there is scarab scarcity, 48% chlorpyrifos emulsion can be used 1000 times liquid, which has a good control effect on scarab beetles and heartworms.
2. Scientific planning of orchards
Pear small heartworm has the characteristics of transfer hazards, and now many friends plant a variety of fruit trees in an orchard, resulting in heartworms transferring hazards between each other, increasing the difficulty of prevention and control. Therefore, it is necessary to avoid planting fruit trees such as pear trees, large cherries, peach trees, and apples adjacent to each other.
Black light booby trap
3. Artificial booby-trapping
Compared with chemical control, the physical method of artificial booby-trapping is used to reduce the density of insect populations, which is more practical. According to the phototropism and flavor of adult heartworms, I use the method of hanging black light and sweet and sour liquid in the garden. The black light is hung at a height of about 2 meters above the ground, and a large basin is placed below, and the adult insects fall into the basin after touching the black light and drown.
Sweet and sour liquid according to the proportion of 1 part of brown sugar, 4 parts of vinegar, 1 part of white wine, 16 parts of water, plus the appropriate amount of insects in the open bottle, hanging at a height of about 1.5 meters in the trunk, you can trap a large number of adult insects.
The new one is slightly shortened to the normal part, and multiple branches can be extracted below
4. Treatment of new shoots
When we find that the new shoots have been harmed by heart-eating insects, we must shorten the new shoots in time to the position of being eaten by heart-eating insects. After a period of time, the short-cut branches will emit several new branches, and we must choose a strong branch as the lead branch and remove the rest.