Control techniques of diseases and insect pests in kiwifruit

Kiwifruit, also known as kiwifruit, fox peach, monkey pear, etc., is a large deciduous woody vine belonging to kiwifruit family kiwifruit. Its origin is in Xiangxi area of Hunan Province, China. Shaanxi Province at the northern foot of Qinling Mountains is the most abundant area of kiwifruit resources in China. The history of folk artificial cultivation reaches more than one thousand years. Let's take a look at the pest control technology of kiwifruit together.

fruit ripeness

[Harm symptoms] When kiwi fruit ripens, there are thumb-like pressure marks on one side of the harvested fruit, slightly concave, brown, dimpled, about 5 mm in diameter, its epidermis is not broken, peeling the cortex shows a slightly yellow pulp, the edge of the disease spot is dark green or water-stained, and the middle is often milky white conical rot, which can expand to the middle of the pulp or even the whole fruit rot within a few days. During storage, the decay rate was 30%.

[Infection process] Wound infection caused by wind, rain, airflow and pruning. At 20℃, after 14~21 days of incubation period, the infected fruit (i.e., the infected young fruit began to infect about 3 weeks after flowering), and the fruit showed damaged symptoms at maturity.

[Control methods] ① bagging young fruits one week after flowering to avoid infecting young fruits. (2) Spraying carbendazim 800 times solution or bordeaux 1:0.5:200 times solution or 80% topozine WP 1000 times solution 2~3 times from the second week after flowering to the fruit expansion period (May ~ August), the spraying interval was about 20 days. (3) Remove the pruned kiwifruit branches and dead leaves to reduce the parasitic sites of pathogens.

root rot

[Harm symptoms] Dark brown water-stained spots occur at the root neck in the early stage, and gradually expand into white silk hypha. The cortex and xylem of the diseased part gradually rotted, with distiller's grains smell. After 8~9 days, sclerotia formed, the size of rapeseed, pale yellow. Later the roots below gradually blacken and rot, causing the entire plant to die.

[Infection process] The disease overwinters in the damaged part by hyphae. The disease begins in April in Wuhan area, occurs seriously from July to September, and stops developing after October. It occurs in orchards with heavy, poorly drained soils.

[Prevention and control methods] ① When building a garden, choose soil with good drainage. In rainy season, do a good job in clearing ditches and draining water. Do not plant too deep. Do not apply undecomposed fertilizer. (2) In March and late June, root irrigation was carried out with 0.5 kg of zinc and 200 kg of water. 3. When the diseased plants are found, dig up the soil at the root neck, carefully scrape off the diseased parts and a little healthy parts, disinfect them with 0.1% mercury chloride, apply Bordeaux slurry, and replace them with new soil after half a month. When the scraped damaged surface is large, apply wax protection and apply decomposed water dung to restore the tree vigor.

stem-end rot

[Harm symptoms] At first, the affected fruit appears obvious water stains at the fruit pedicle, and then the disease spots spread evenly downward. The flesh decays downward from the fruit pedicle and spreads to the whole fruit. It has a slight transparent feeling and a smell of alcohol. A layer of uneven villous gray mold grows on the pericarp of the affected part, and then turns gray. The fruit rot rate during storage was 20~40%.

[Infection process] The pathogen overwinters in the diseased part as conidia and is transmitted by airflow. In spring, the fungus infects flowers first and causes flower rot. Fruit infection occurs during harvesting, grading and packaging. A large number of spores formed in kiwifruit orchards from flowering to petal dropping. The infected fruits of kiwifruit appeared symptoms after 4 weeks under cold storage (0℃), and the infected fruits did not appear symptoms after 12 weeks.

[Prevention and control methods] ① Do a good job in winter garden cleaning. (2) Remove the diseased flowers in time and burn them intensively. Spray fungicides once in the late flowering stage and before harvest, such as double Bordeaux mixture or 65% zinc 500 times solution. (3) Before harvest, the medicine should be applied to the fruit stalk as much as possible. The wound and whole fruit should be treated with medicine within 24 hours after harvest. For example, 50% carbendazim 1000 times solution plus "24-D" 100~200ppm should be soaked for 1 minute.

leafhoppers

[Harm symptoms] Adult nymph sucks the sap of bud leaves and branches of kiwifruit trees. Yellow-white spots appear in the early stage of leaf surface damage, gradually expanding into pieces. In severe cases, the whole leaves are pale and fall early, the tree body is weak, and the yield decreases sharply.

[Infection process] Four generations occur a year, and the fourth generation adults overwinter in winter green manure crops and weeds. In early spring, the overwintering adults begin to mate and lay eggs. The egg stage is 7~10 days, and the nymph stage is 15~20 days. The first generation adults lay eggs in the middle and late April. The eggs are laid in the mesophyll near the main vein on the back of the leaf. A small number of eggs are laid in the mesophyll near the lateral veins, and 4 - 10 eggs are laid at a time. The second generation adults occurred from the middle of June to the middle of July, which was the peak period of the whole year, with an average of 13.9 per leaf.

[Control methods] ① Select resistant varieties to cultivate, kiwifruit deliciousness (such as Jinkui variety) is less damaged than Chinese kiwifruit. (2) Choose suitable shelving, the occurrence of this pest is related to the intensity of light, the damage of shelving is heavier, and the T frame and fence frame are lighter. 3. Clean and disinfect the orchard, remove weeds in and around the orchard, and plough green manure back to the field in time in winter. (4) Spraying 40% dimethoate 1:1200 solution at the peak of adult emergence, the control effect was 99.3%, spraying 10% Duolaibao 1:2500 solution, the control effect was 99.6%. 25% dimefon 3000 times solution or 50% pirimicarb 4000 times solution and other pyrethroids can also be sprayed, and good control effect can be obtained.

Fruit-sucking moth

[Symptoms] When the fruit is near maturity, adults use siphoning mouthparts (with thick and sharp mouthparts, with many small thorns on the end and sides of the beak) to pierce the kiwi peel and suck the juice. The puncture hole is very small and difficult to detect. After about 1 week, the pericarp at the puncture hole turns yellow and sunken and flows out glue. Then the wound is soft and rotted, and gradually expands into oval water-stained patches. Finally, the whole fruit decays.

[Infection process] In Wuhan area, 3~4 generations occur every year, larvae and adults can overwinter, from late May to mid-November without interruption, and three peak periods occur in mid-late June, mid-late August, mid-September to mid-October, and each generation adult period is about 38 days. Most of the damaged kiwifruit are the third generation adults. The larvae of each generation mostly feed on wood and Chinese.

[Prevention and control methods] ① Do a good job in cleaning and disinfecting the orchard, and uproot the orchard and its surrounding wood and Chinese defenses. (2) bagging kiwifruit from young fruit stage. Before adults harm, soak melons and fruits in 15 times solution of highly toxic pesticide fluoroacetic acid amine for 1 minute, hang them in orchards to trap them, but pay attention to human and animal safety. According to the principle that fruit sucking moth likes ultraviolet spectrum, black light lamp can be placed in orchard to trap and kill fruit sucking moth. It can also be trapped by hanging bottles of 8% sugar and 1% vinegar aqueous solution plus 0.2% sodium fluoride. 4. In 10 mu kiwifruit orchard, 6 golden fluorescent lamps with 40 watts could reduce the damage of fruit sucking moth.

hepialus moth

[Harm symptoms] The larvae damage the cortex and xylem at the base of the trunk about 50 cm and the base of the main vine. When they are eaten, they first spin silk nets to hide the worm body, then send out the bitten sawdust while eating, stick to the silk net, and finally connect into packages to cover the hole. Sometimes the larvae gnaw a transverse groove on the branches and then bite into the pith, thus often causing the bark ring to cut, so that the upper branches wither or break. Worm channel mostly from the pith down to eat, sometimes deep underground roots, worm channel smooth inner wall. Before pupation, the cyst of the worm increases and turns brown. It bites a round hole first, and blocks the opening with silk cover at the inner mouth of the worm channel to prepare for pupation.

[Infection process] One generation per year, a few biennial generations, overwintering as eggs on the ground or larvae in tunnels at the base of trunk, hatching in mid-April of next year. The first instar larvae feed on humus, and after 2 or 3 instars turn to eat roots in the internal neck. The adults appear from late August to September.

[Control methods] ① Insectivorous birds, predatory beetles and parasitic flies all have certain inhibitory effects on the occurrence of bat moths.② When insect packs are found at the base of the trunk, tear off the insect packs and insert thin iron wires into the insect holes to kill the larvae. Or use 50% dichlorvos 50 times liquid instillation, or use cotton ball dip liquid medicine into the bore hole. Or with aluminum phosphide tablets, 0.1 grams per hole can be used, the orifice with wet mud plug, poison larvae. (3) Remove miscellaneous trees near orchards, such as yellow wattle, wild tung and other host plants. 4. Combine pruning to cut off injured vines and burn them. (5) spray 10% cypermethrin 2000 times solution under canopy and dry base to kill 2nd and 3rd instar larvae in ground activity stage.