Main Pests and Diseases of Cherry Cultivation and Their Control Methods

Cherry brown rot

Mainly damages flowers and fruits, causing flower rot and fruit rot. In the early stage of the disease, the floral organs gradually turn brown until they dry up; later, a layer of grayish-brown powdery substance forms on the diseased part. Starting from 10 days after flower drop, young fruits begin to develop the disease, with small light-brown spots forming on the fruit surface, gradually spreading into dark-brown lesions. Young fruits do not become soft and rotten, but when mature fruits are affected, small light-brown spots first appear on the fruit surface and spread rapidly, causing the whole fruit to become soft and rotten.

Control measures: 1) Clean the orchard, sweep up fallen leaves and fallen fruits and burn them; 2) Prune reasonably so that the canopy has good ventilation and light conditions; 3) Spray 3-5 degree lime sulfur mixture once before bud break; 4) During the growing season, spray once every 10-15 days, for a total of 4-6 sprays. The agents can be 1:2:240 Bordeaux mixture or 77% Kocide 500 times solution, 50% captan 500 times solution.

Cherry gummosis

Mainly damages the main trunk and main branches of cherry. It generally begins to occur when the tree sap starts flowing in spring. In the early stage, the branch forks or wounds swell, and a yellow-white translucent sticky substance flows out. The cortex and xylem become brown and decay, leading to weakened tree vigor, and in severe cases the branches die. The causes of the disease are, first, wounds caused by branch diseases, insect pests, freezing injury, and mechanical injury leading to gummosis; second, excessive pruning, improper fertilization, excessive water, and poor soil physical and chemical properties, which lead to disorder of the tree's physiological metabolism and cause gummosis.

Control measures: 1) Apply more organic fertilizer to make the tree vigorous and prevent drought, waterlogging, and freezing injury; 2) Do a good job in pest and disease control to avoid causing too many wounds; 3) Winter pruning is best done before sap flow, and in summer reduce large pruning and saw cuts as much as possible; 4) When gummosis is found, scrape it off promptly and then apply medicine for protection. Commonly used agents include a mixed solution made by adding water to 1 part 50% Tuzet, 5 parts 50% suspended sulfur, and a mixed solution made by adding water to 10 parts quicklime, 1 part lime sulfur mixture, 2 parts salt, and 0.3 part vegetable oil.

Cherry leaf spot

This disease mainly damages leaves, and also damages petioles and fruits. In the early stage of leaf disease, purple or brown necrotic spots appear between the veins on the upper surface of the leaves, and at the same time pink mold-like substances form on the back of the spots. Later, as the spots expand, several spots join together and cause most of the leaf to die. Sometimes the leaves also form perforations, causing early leaf drop. Leaves generally begin to develop the disease in May, and the disease is severe in the high-temperature, rainy season from July to August.

Control measures: 1) Strengthen cultivation, enhance tree vigor, and improve the tree's disease resistance; 2) Remove diseased branches and diseased leaves, burn them in a centralized manner or bury them deeply; 3) Spray 3-5 degree lime sulfur mixture before bud break; 4) From after flower drop to before fruit harvest, spray 1-2 times with 70% mancozeb 600 times solution or 75% chlorothalonil 500-600 times solution, Daconil M-45 800 times solution, etc., once every 10-14 days.

Cherry pouch gall aphid

Occurs in multiple generations a year, overwintering as eggs on young cherry branches. When buds sprout in spring, the eggs hatch into stem mothers. At the end of March, the stem mothers form peanut-shell-shaped pseudogalls on the lateral edge of the leaf tip, and develop, damage, and reproduce inside the galls. The damaged leaf back is sunken and the leaf surface protrudes in blister-like galls. The gall is 2-4 cm long, initially slightly red, later turning withered yellow. At the end of April, winged parthenogenetic aphids appear and migrate outward. In mid-to-late October, sexual aphids are produced and lay eggs on young branches to overwinter.

Control measures:

1) In orchards with a small occurrence, the galls can be removed manually by pruning;

2) In early March, after the eggs of the pouch gall aphid hatch and before the galls form, spray 40% omethoate or 50% phoxim emulsion 2000 times solution, or spray the above agents in October when sexual aphids appear.

Cherry bacterial shot hole disease

This disease mainly damages leaves. It first produces semi-transparent water-soaked light-brown small spots, which gradually expand into irregular dark-brown lesions surrounded by a yellow halo, and finally the lesions dry up and fall off to form shot holes. It occurs from May until the leaf-fall period, with the heaviest occurrence from August to September.

Control measures: Basically the same as for cherry leaf spot. In addition, 65% zineb 500 times solution can be sprayed in May and June.

Cherry pest - spirea aphid

Occurs for more than 10 generations a year, mainly overwintering as eggs beside buds on cherry branches or in bark crevices. In the next year in early-to-mid April when buds sprout, the eggs begin to hatch. Newly hatched young aphids gather on the underside of leaves to feed, and after about 10 days they produce wingless viviparous female aphids. From June to July, the temperature rises, reproduction accelerates, the population density increases rapidly, and the damage is severe. From August to September, the aphid population begins to decrease. In October, sexual aphids begin to be produced, males and females mate and lay eggs, and overwinter as eggs.

Control measures: 1) Before leaf expansion, when overwintering egg hatching is basically finished, spray 40% dimethoate or 70% aphid-killing wettable powder 1500-2000 times solution; 2) In early May during the initial outbreak of aphids, apply chemicals to the trunk. If the bark is rough, first scrape off the rough bark until it is slightly white. Commonly used systemic agents include 40% dimethoate emulsifiable concentrate, or 50% monocrotophos emulsifiable concentrate 2-3 times solution. Apply a 6 cm ring band on the middle part of the main trunk with a brush. If there are many aphids, apply the chemical again at the original site after 10 days; 3) If conditions permit, artificially rear predatory natural enemies such as ladybugs and lacewings.

Cherry pest - Phalera flavescens

Occurs 1 generation a year, overwintering as pupae in the soil layer at the tree base. In the second year from early July to mid-August, they emerge as adults, hide by day and come out at night, and have strong phototaxis. Eggs are mostly laid on the underside of leaves. Larvae before the 3rd instar gather on the underside of leaves to damage, and damage in the early morning, evening, and at night. Resting larvae are neatly arranged along the leaf edge with heads and tails raised. If disturbed, they drop in groups on silk threads. In September, after the larvae mature, they enter the soil and pupate to overwinter.

Control measures: 1) Combine autumn plowing or spring digging around the tree base to expose overwintering pupae to the ground so they die from dehydration; 2) Make use of the habit of gathering to feed before the 3rd instar and dropping when startled to manually remove branches and leaves with gathered insects; 3) During the damage period, spray 50% fenitrothion emulsifiable concentrate 1000 times solution or 20% fenvalerate 2000 times solution.

Control of white peach scale on greenhouse cherries

White peach scale is an important pest on cherry. When the damage is severe, it causes weakened tree vigor and even death. Because of the change in the microclimate inside the greenhouse, in recent years the occurrence pattern of white peach scale in greenhouse-cultivated cherries has also changed accordingly. For this reason, preliminary observations were made on the occurrence pattern of white peach scale, and chemical control trials were carried out in order to clarify the best period, chemical types, and concentrations for controlling white peach scale.

I. Investigation content and control trials:

1. Investigation of occurrence pattern.

The occurrence periods of each generation and each insect stage of white peach scale on greenhouse cherries were observed and investigated.

2. Chemical control trials.

Test agents: 30% Lajieling emulsifiable concentrate (produced by Yantai Fushan Chemical Plant), 40% Supracide emulsifiable concentrate (produced by Novartis, Switzerland), 48% Lesben emulsifiable concentrate (produced by Dow AgroSciences, USA), lime sulfur mixture (self-made).

Test method: For the control trial of overwintering female adults, 5 treatments were set: 30% Lajieling 800 times, 1000 times, 40% Supracide 1500 times, lime sulfur mixture, and water control. Each treatment was repeated 3 times, with 3 trees per replicate, arranged in randomized blocks. Spraying was carried out with a Gongnong Model 26 sprayer during the period when female adults began activity.

For the control trial of the first-generation nymphs, 6 treatments were set: 30% Lajieling 800 times, 1000 times, 40% Supracide 1500 times, 48% Lesben 1000 times, 1500 times, and water control. Each treatment had 3 replicates, with 3 trees per replicate, arranged in randomized blocks. Spraying was carried out with a Gongnong Model 26 sprayer during the dispersal period of the first-generation nymphs.

Efficacy investigation and calculation method: For the efficacy against overwintering female adults, investigations were conducted once 15 days and once 30 days after spraying. The wax shell was removed with a needle, and insects whose bodies turned black were recorded as dead. The number of live insects and dead insects was recorded, and the corrected mortality rate was used to express the control effect. For the first-generation nymph efficacy investigation, the base number of insects was investigated before spraying, and the number of residual live insects was investigated 4 days and 10 days after spraying, with the corrected population decline rate used to express the control effect.

II. Results and analysis:

1. Occurrence pattern.

According to the investigation: white peach scale occurs for 2 generations a year in the greenhouse. Overwintering fertilized female adults begin activity in mid-to-late February and feed and cause damage. They begin laying eggs in late March. The first-generation nymphs begin hatching in early April, enter the peak hatching period in mid-April and crawl out of the scale to move about, begin fixed damage in early May, reach the peak emergence period in late May to early June, begin laying eggs in mid-June, and reach the peak egg-laying period in late June. In late June, the second-generation nymphs begin hatching, enter the peak hatching period in early July, become fixed and damage in mid-July, and begin emergence in late July.

2. Chemical control trials.

The trials showed that 30% Lajieling and lime sulfur mixture had very low control effects on overwintering female adults of white peach scale, and the control effect of 40% Supracide reached 80.08% 30 days after treatment.

The results of the first-generation nymph control trial showed that 4 days after treatment, the control effects of 30% Lajieling 800 times and 1000 times solutions were 96.57% and 88.98% respectively; with 48% Lesben 1000 times and 1500 times solutions, the control effects were 96.81% and 95.60% respectively; while the control effect of 40% Supracide was 100%. Ten days after treatment, the control effects of all concentrations of 30% Lajieling and 48% Lesben were above 95%, and 40% Supracide was still 100%.

III. Summary:

The occurrence of each generation and each insect stage of white peach scale on greenhouse-cultivated cherries is 1 month earlier than in the open field. Overwintering female adults begin activity in mid-to-late February, and the dispersal period of the first-generation nymphs is in early-to-mid April.

Chemical control should grasp two key periods: 1. After the greenhouse is covered, before cherry flowering, spray branches and trunks with 40% Supracide 1500 times solution to control overwintering female adults. 2. During the dispersal period of the first-generation nymphs in early-to-mid April (that is, after egg hatching and before nymph fixation), spray 48% Lesben 1500 times solution or 30% Lajieling 1000 times solution, which can control the damage of white peach scale. At this stage, the nymph body surface has not yet secreted wax powder to form a wax shell, pesticides are easy to contact the insect body, and the nymphs have low resistance to chemicals. Using chemicals during this period can significantly improve the control effect, and it is the best period for controlling white peach scale. Because 40% Supracide is a highly toxic pesticide and has a long residual effect period, and the fruit is nearing maturity, it is not suitable for use.

After the greenhouse covering is removed, spray chemicals in early July to control the second-generation nymphs. The types and concentrations of chemicals used are the same as above. In addition, pruning off heavily infested branches before covering the greenhouse, or brushing off overwintering insects on branches and trunks, can both improve the control effect.

Main pests of greenhouse cherries

I. Red-necked longhorn beetle

1. Damage symptoms: Newly hatched larvae first bore and feed under the bark of branches and trunks, and the insect holes are arranged irregularly. In the second year, older larvae bore deep into the xylem to feed, boring out tunnels, and discharge sawdust-like reddish-brown frass outward from the bore holes.

2. Control (1) Manual control: During the period when small larvae damage under the bark, once frass is found, dig them out manually; or use a veterinary syringe to inject 80% dichlorvos emulsifiable concentrate 800 times solution, or 50% phoxim emulsifiable concentrate 500 times solution into the insect tunnel, then seal it with mud to kill them with the chemical. In addition, adults can also be manually killed. (2) Repellent control: Before adult emergence, brush the branches and trunks with a whitewash made from 10 parts quicklime, 1 part sulfur, and 40 parts water to prevent adults from laying eggs.

II. Golden buprestid beetle

1. Damage symptoms: Newly hatched larvae first damage in the old bark layer of branches and trunks. As the insect body grows, it goes deep between the cambium and xylem and feeds in a string-like manner. The damaged tree exudes gum, and in severe cases the whole plant dies.

2. Control (1) During the adult occurrence period, manually shake the adults off the tree every 2-3 days and kill them. (2) During the larval damage period, manually dig out the larvae in branches and trunks. (3) Strengthen branch and trunk protection to prevent mechanical wounds and avoid and reduce adult egg-laying. (4) Remove aged trees: Aged trees that have lost the ability to bear fruit should be removed.

III. Apple clearwing moth

1. Damage symptoms: After hatching, the larvae bore and feed under the bark of branches and trunks, causing gummosis.

2. Control (1) Manual control during dormancy: After leaf fall and before bud break, when reddish-brown frass is found on branches and trunks, manually dig out the larvae. (2) Chemical smearing control: Before and after bud break, when reddish frass is present on branches and trunks, smear 5 times dichlorvos solution with medicated cotton or a brush to kill the larvae. (3) Chemical control: During the adult occurrence period, spray 30% Taoxiaoling emulsifiable concentrate 2000 times solution.

IV. White peach scale

1. Damage symptoms: Mostly nymphs and female adults gather on branches to suck sap. 2-3 year old branches suffer the most, and the damaged parts are slightly sunken.

2. Control (1) Manual control: During winter dormancy, manually scrape and brush the bark to eliminate overwintering female adults. (2) Chemical control during dormancy: At bud break, spray once with 5% anthracene oil emulsion, or 5 Baume degree lime sulfur mixture. (3) Chemical control during the growing season: At the peak hatching period of each generation of nymphs, spray once with 50% parathion emulsifiable concentrate 2000 times solution, or 50% dichlorvos emulsifiable concentrate 1000 times solution, or 2.5% kungfu emulsifiable concentrate 3000 times solution. (4) Biological control: The small black ladybug is an important natural enemy and should be protected and utilized.

V. Korean globular scale

1. Damage symptoms: Nymphs and female adults suck sap on branches and leaves, affecting flowering, fruit set, and tree development.

2. Control (1) Chemical control during dormancy: Near bud break, spray once with 5 Baume degree lime sulfur mixture to kill nymphs. (2) Chemical control at the peak occurrence period of nymphs: Spray 30% Manjieling emulsifiable concentrate 1500 times solution.

VI. Giant mealybug

1. Damage symptoms: Nymphs gather to damage young branches, young buds, and leaves, and in severe cases also damage fruits, resulting in poor tree development.

2. Control (1) Dormancy-period control: In early February, apply a 10 cm wide sticky insect glue ring on the trunk. Poison and kill nymphs climbing up the tree. In the soil around the trunk, dig out and kill egg sacs. (2) Chemical control during the nymph period: Spray 20% Taoxiaoling emulsifiable concentrate 2000 times solution.

VII. Large gray weevil

1. Damage symptoms: Adults damage new buds and young leaves of nursery stock, and the young buds and young leaves of newly planted young trees. After hatching, larvae bore into the soil and feed on root tissues.

2. Control (1) Manual control during the adult occurrence period: Make use of their death-feigning behavior and capture them manually. (2) Manual control before nursery stock bud break: On the nursery stock training belt, put on a plastic film tube with the opening facing downward and the upper opening tied tightly to prevent adults from climbing up and feeding.

VIII. Brown marmorated stink bug

1. Damage symptoms: Adults and nymphs suck the sap of leaves, young shoots, and fruits. Young fruits become uneven and deformed. If damaged before maturity, the fruit flesh sinks and forms hardened, stiff blocks.

2. Control (1) Manual control: Manually capture overwintering adults. Manually eliminate egg masses and newly hatched nymphs. (2) Chemical control: During the nymph hatching period, spray 50% parathion emulsifiable concentrate 1000 times solution or 40% dimethoate emulsifiable concentrate 1000 times solution, or 20% fenvalerate emulsifiable concentrate 3000 times solution.

IX. Green plant bug

1. Damage symptoms: Adults and nymphs suck the sap of young stems, young leaves, flowers, and fruits. Damaged leaves appear needle-pricked, and young fruits form rust spots or hard lesions.

2. Control (1) Manual control: Eliminate weeds inside and outside the orchard to eliminate overwintering eggs. (2) Chemical control: During the nymph period, spray 20% fenpropathrin emulsifiable concentrate 2000 times solution; during the adult egg-laying period, spray once with cypermethrin emulsifiable concentrate 2000 times solution to kill adults and eggs.

X. Pear lace bug

1. Damage symptoms: Adults and nymphs pierce and suck on the underside of leaves. Pale spots form on the leaf surface; the leaf underside becomes rust-yellow due to brown spots, frass, and flyspeck-like black spots left by egg-laying.

Control (1) Manual control: In spring, scrape and brush rough bark crevices on branches and trunks, collect broken bark and overwintering adults and burn them. (2) Chemical control: During the first-generation nymph period, spray 50% parathion emulsifiable concentrate 2000 times solution, or 30% Taoxiaoling emulsifiable concentrate 2000-2500 times solution.

XI. Apple fruit chafer and black velvet chafer

1. Damage symptoms: Adults bite and feed on young buds, young leaves, and flower buds. After hatching, larvae feed on young roots underground.

2. Control (1) Manual control: Make use of their death-feigning behavior, shake them off and kill them. (2) Trapping and killing: Use black light lamps to trap and kill. (3) Chemical control: During the adult occurrence period, spray 50% parathion emulsifiable concentrate 1000-1500 times solution or 30% Taoxiaoling emulsifiable concentrate 2000 times solution. Spraying should preferably be carried out 2-3 days before flowering. (4) Ground control: Before adults emerge from the soil, broadcast 5% phoxim granules, 30 kg per hectare. After broadcasting, shallow hoe the ground.