What pesticides do peach trees use?

Peach tree is a common fruit tree in China, which is planted in a wide area, and it begins to appear on the market in large quantities every June, which is very popular in the market. during the period of planting peach trees, it is necessary to spray appropriate amount of pesticides to control diseases and insect pests. What pesticides do peach trees use?

1. Leaf shrinking disease

Damage symptoms: peach leaf shrinking disease mainly harms young parts of peach trees, mainly damage leaves, serious damage can also be harmful flowers, shoots and young fruits. Leaves: the tender shoots appear curly and red as soon as they are drawn from the bud scales in spring. With the gradual development of the leaves, the degree of curl and shrinkage increased, and the leaves thickened and became brittle and reddish brown. There is a layer of gray-white powder on the leaf surface in late spring and early summer, that is, the ascomycete layer of the pathogen. Finally, the diseased leaves turn brown and scorch and fall off. After the leaves fall off, the axillary buds often germinate and draw out new shoots, and the new leaves are no longer damaged. Shoot: the tip of the branch is grayish green or yellow after being damaged, which is shorter than the normal internodes, and is slightly swollen, and the leaves on it are often clustered. In severe cases, the whole branch withered.

Prevention and cure method

(1) Pesticide control: when the petals are red (not yet unfolded), spraying 2-3 Baumedo stone sulfur mixture or 100 Bordeaux solution with 1-1 Bomedo is very effective in killing overwintering pathogens on trees.

(2) strengthening management: timely removal of diseased leaves and concentrated burning can reduce the source of overwintering bacteria in the current year. For peach trees with serious disease, due to a large number of scorched and shedding leaves, more fertilizer should be applied in time, cultivation and management should be strengthened to promote the restoration of tree potential.

2. Iron deficiency yellow leaf disease of peach trees

Damage symptoms: green reticulate chlorosis. With the development of the disease, the degree of chlorosis of the leaves increased, the whole leaves turned white, the leaf margin became scorched, and the leaves fell. When there is a serious iron deficiency, the tip of the new shoot dies.

Prevention and cure method

Soil improvement and the release of fixed iron are the fundamental measures for the prevention and treatment of iron deficiency, and the proper supplement of soluble iron can treat diseased trees.

3. Peach tree gum disease

Symptoms of damage: translucent yellow gum is released from the disease, especially after rain. After the outflow of gum comes into contact with air, it becomes reddish brown and jelly-like, and becomes a hard block of reddish brown to tea brown after drying. The diseased part is easy to be infected by saprophytic bacteria, which browns the cortex and xylem, weakens the tree potential, turns the leaves yellow and smaller, and severely punishes the branches or the whole plant.

Prevention and cure method

(1) strengthen the management and strengthen the tree potential. Increase the application of organic fertilizer, pay attention to drainage in low-lying waterlogged land, properly apply lime or superphosphate in acid-alkali soil, improve soil, pay attention to salt discharge, reasonable pruning, reduce branch wounds and avoid continuous cropping in peach orchard. Control branch diseases and insect pests, prevent diseases and insect pests, early control peach tree pests such as shell insects, aphids, longicorn beetles and so on. White tree trunks in winter and spring to prevent frost injury and sunburn. The branches with severe glue flow were scraped in autumn and winter, and the wounds were disinfected with Baume 5mur6 degree stone sulfur mixture or 100x copper sulfate solution, or brushed with 1:4 alkali water, which also had a certain curative effect.

(2) what is the pathogen of infectious peach gum? How many fungi cause it? What are the characteristics of their hyphae? Which medium is suitable for the fungus and what is its formula?

(3) the peach gum disease mostly occurred in the main branches, trunks and fork corners of peach trees. at the initial stage of the disease, the disease expanded slightly, overflowed hyaline gum, and became more serious after rain, and then the gum gradually became jelly-like, water loss showed yellowish brown, and finally turned into a hard amber-like glue. The disease of the fruit is caused by the overflow of yellow colloid in the core, overflow of the fruit surface, hard part of the disease, sometimes ruptured and inedible.

(4) all wounds caused by insect injury, disease injury, frostbite, hail injury, sunburn, etc., can cause non-invasive peach gummy disease (no pathogen). In addition, due to the physiological dysfunction caused by soil viscosity, poor drainage, excessive or insufficient irrigation, the flow gum is formed, which is an infectious peach gum disease caused by fungi, and the spores of its asexual generation are transmitted by wind and rain. from the wound and lateral buds invaded, there are two peaks in a year, that is, from late May to early June and from early August to early September.

If you want to control peach gum disease, it is necessary to spray in time to control diseases and insect pests and white the trunk to avoid frost injury, sunburn and mechanical trauma. At the same time, it is necessary to strengthen fertilizer and water management, enhance the tree potential and improve the disease resistance of the tree.

4. Peach scab (scab)

Damage symptoms: fruit disease is mostly in the shoulder of the fruit, first produce dark brown round spots, and then show black nevoid spots, the diameter is 2mm 3mm, when the disease spot aggregates into a piece. Cracking often occurs in diseased fruit. The damage to the fruit stem often falls off in the early stage; after the new shoot is killed, it presents an oblong, light brown spot with a size of 3 × 6 mm, then becomes dark brown, and further expands, the disease part is raised, and glue flow often occurs. The boundary between the disease and healthy tissue is clear, and the bacteria do harm only on the surface and do not go deep inside. In the next spring, dark cashmere spots can be produced on the disease spot, and irregular or polygonal gray-green disease spots appear on the back of the leaves. Later, the disease turned dark or purplish red, and finally the disease dried up and fell off and formed a perforation. The plaque is small, rarely more than 6 mm. Long dark brown spots can be formed on the midrib. When the disease is serious, it can cause fallen leaves.

Prevention and cure method

(1) remove the source of primary infection: combined with winter shears, remove diseased kernels, stiff fruits and stumps, burn or bury them deeply. During the growing period, diseased branches and withered branches can also be cut off and diseased fruits can be removed.

(2) Chemical control: spray Baume 5 degree stone sulfur mixture 0.3% pentachlorophenol sodium or 45% crystal stone sulfur mixture 30 times before flowering. Half a month after falling flowers, 70% mancozeb wettable powder or 80% anthrax Fumei wettable powder and 70% thiophanate methyl wettable powder were sprayed half a month, and the above agents were used alternately with 0.5 1100O zinc sulfate lime liquid or 0.3 Baomedu stone sulfur mixture, once every half a month, for a total of 3 times.

(3) strengthen management: pay attention to drainage after rain, reasonable pruning to prevent branches and leaves from being too dense.

(4) selection of disease-resistant (disease-avoiding) varieties: where the disease is often serious, early-maturing varieties can be selected.

(5) fruit bagging: bagging was carried out 3-4 weeks after falling flowers.

5. Peach perforation

Damaging symptoms

The main results are as follows: (1) bacterial perforation is the most widely distributed, mainly harmful leaves, but also harmful shoots and fruits. The injured leaves first appeared oil-stained spots, then expanded into round or irregular spots, brown to purple-brown, and there was a yellowish-green halo ring around the spots. when the weather was wet, the diseased part overflowed viscous bacterial pus, and soon the diseased part withered and fell off and perforated. Damage to branches can cause ulcers: one is spring ulcers. Small dark brown scabs appear on branches during leaf expansion in spring, which mostly occur on branches extracted and infected last summer. Disease spots can spread vertically and horizontally to branches, and in severe cases, they can dry up. The other is summer ulcer, which mostly occurs on the new shoots extracted in the same year, with the host lenticle as the center, showing oily brown to purple-brown round or oval, slightly sunken spots, but the expansion of the spot is limited and the infectivity is not great.

(2) Brown, round or amorphous disease spots appeared after the injury of the leaves of mildew spot perforation, and the gray-black mold layer grew on the back of the disease spot when it was wet, and finally the disease part fell off and perforated. The damage to the shoot showed long oval black-brown spot, purple-brown edge, cracking and glue flow. The damaged fruit showed brown spots, red at the edge and slightly sunken in the middle. 3. The disease spot of brown spot perforation disease leaf is round or nearly round, brown, the edge is slightly reddish brown with ring pattern, and there are grayish brown mildew layer on both sides when it is wet. Finally, the disease part is dry, shedding and perforating, and the edge of perforation is neat. The disease spot on the new shoot and fruit is similar to the leaf spot, and the mildew layer grows when it is wet.

Prevention and cure method

The main results are as follows: (1) doing a good job of clearing the garden in winter combined with clearing the garden in winter, thoroughly removing withered branches, fallen leaves and fruits, and spraying 1-2 Bomedo stone sulfur mixture before germination in spring can greatly reduce the source of overwintering bacteria.

(2) strengthen the management of fertilizer and water, increase the application of organic fertilizer and phosphorus and potassium fertilizer, and maintain a moderate amount of fruit, so as to keep the tree potential strong and enhance disease resistance.

6. Peach anthracnose

Harmful symptoms: the young fruit soon withered into the hanging branch of the fruit; the larger fruit was sunken and brown after the disease, and produced pink slime (bacterial spores) when it was wet, and the diseased fruit fell off quickly, or the whole fruit rotted and lost water to become the hanging branch of the fruit. The disease of the branch mainly occurred on the fruiting branch in early spring, the disease spot was brown, oblong, slightly sunken, accompanied by glue flow, and the disease spot was also covered with pink spores when the weather was humid. When the disease spot surrounded the branch for one week, the upper part of the branch withered, the dead part of the diseased branch at the end, the leaf atrophied and drooped, and rolled into a tube.

Prevention and cure method

(1) carefully remove withered branches, stiff fruits and stumps from trees during winter pruning to eliminate the source of overwintering disease. Perennial senescent branches and weak branches are easy to accumulate and hide pathogens, and should also be cut off. At the same time, the main and side branches that are too high and too large should be retracted to facilitate the renewal and rejuvenation of the crown and branch groups and the work of garden cleaning and spraying.

(2) the first diseased branches should be cut off in time from bud germination to flowering to prevent re-infection, and the fruit branches found with leaf curling symptoms should also be cut off and buried deeply.

(3) selecting disease-resistant varieties.

(4) strengthen drainage, apply more phosphorus and potassium fertilizer, strengthen the tree potential, and avoid leaving branches too dense and too long.

7. Peach stem blight

Damage symptoms: in the early stage of the disease, the cortex was slightly swollen, slightly purplish red and glue appeared, and finally the cortex turned brown and died, with the smell of lees, and black protuberances were produced on the surface. When the tree is strong, the disease spot sometimes heals itself. when the tree is weak, the disease spot quickly spreads to both ends and sides, resulting in the death of the branches. At the initial stage of the diseased branches, the new shoots grew poorly, the leaves turned yellow, and the old leaves curled and scorched, and then withered with the development of the disease.

Prevention and cure method

The main results are as follows: (1) strengthen the management of fertilizer and water in orchard, prune reasonably, keep fruit reasonably and prevent the decline of tree potential.

(2) after scraping off the spot with a sharp knife, brush the wound with 100 times of 20% antibacterial agent 402 or 100 times of copper sulfate.

(3) during the growing period of peach trees, when spraying carbendazim, zinc and zinc-copper lime solution to control other diseases, attention should be paid to the spray protection of branches and cadres.

8. Peach root cancer

Damage symptoms: mainly in the root neck, but also in the lateral root or branch root, the tumor at birth milky white or reddish, smooth, soft, after gradual brown, Lignification and hard, rough surface, uneven. The tumor occurred in the branch root was smaller, the root neck was larger, and the tumor in the root neck had the greatest influence. The damaged peach tree grew badly, the plant was short, the fruit was few and the quality was poor, and the whole plant died when it was serious.

Prevention and cure method

(1) continuous cropping in seedling field and peach orchard should be avoided as far as possible.

(2) the diseased seedlings should be strictly removed when the seedlings come out of the nursery, and the quarantine should be strengthened to prevent the diseased seedlings from being brought into the new peach orchards.

(3) strengthen orchard inspection, dig up the topsoil of suspected diseased plants, scrape or thoroughly scrape them with a knife and disinfect them with 1% sodium pentachlorate or 0.1% liter of mercury; they can also soak the roots (on diseased seedlings) or splash the roots (big trees) with 20-fold solution of Genyaling.

(4) the nursery should use disease-free soil to raise seedlings and cultivate strong and disease-free seedlings.

(5) strengthen soil management, apply fertilizer reasonably, improve soil and enhance tree potential.