What are the causes of walnut black fruit and the symptoms and prevention measures?

Walnut black fruit is a common disease in the process of walnut planting, and the phenomenon has occurred seriously in recent years, which seriously affects the brand and yield of walnut and causes great losses to farmers. This article introduces in detail the causes, symptoms and prevention measures of walnut black fruit.

1. NuclearThe causes and symptoms of peach black fruit

Walnut black fruit is mainly walnut borer, there are also bacterial black disease, peach heartworm and some fruit flies, fruit elephants and other common hazards are formed, but walnut borer and bacterial black disease are the main hazards.

Walnut scab is a bacterial disease, mainly affecting walnut fruits and leaves, young fruits are affected by its consequences as brown tear-like impregnated dots, and then expand into round or irregular shapes, no obvious edges, surrounded by water soaking, when the disease sinks, penetrates deep into the endocarp, and makes the whole fruit blackstar rot, the kernel dries up, and the fruit falls early.

The damage rate of walnut pests and diseases is related to climatic conditions, management level, site conditions and the number of pests and diseases in the previous year. The black fruit rate of walnut orchards in gully area with poor stand conditions or high precipitation, high humidity, low management level, declining tree potential, excessive cultivation density, poor ventilation and light transmission, serious occurrence year after year, and no prevention and control were serious.

2. Comprehensive control measures for walnut black fruit

1.Agricultural control.

Every year after the walnut is harvested to the middle of May of the following year, before the adult limb moth emerges, the trees under the canopy are cultivated and cultivated, and the dead branches and leaves and weeds are removed, and the limb moth is controlled before the limb moth emerges. This loosens the soil, stores water and moisture, promotes tree growth, and more importantly, makes it impossible for the moth's overwintering larvae to pupate in the deeper layers of the soil. For walnut trees that are inconvenient to cultivate, overgrown with weeds, deep ditches and slope feet, the turf should be removed, the dead branches and fallen leaves should be removed, and the deep burial or burning should be concentrated, which also has a certain effect.

2.Ground application turned off.

At the beginning of May, before the adult emergence, or when the individual adult emerges, the adult is poisoned with imidacloprid solution. In mid to early August, when the larvae are fledgling, the ground application of the above method can also be used to poison the fledgling larvae.

3.Pick up the black fruit and bury it deeply.

From late June to early August every year, it is the season when black walnuts are on the market, and propaganda agencies and summer students should pick black fruits on and under the trees in time. You can also set up points in areas with heavy black walnuts to buy black fruits with a certain **. Black fruits picked or purchased should be destroyed or buried in a deep pit away from the walnut tree (medium.

Black fruit must be picked continuously for three years to achieve more than 90% control effect.

4.Chemical control.

For walnut pests and diseases that have been very serious in previous years and concentrated in walnut orchards for many years, canopy spraying can be used as an emergency control measure to ensure the yield of walnuts in the current year, and pay attention to the careful alternate use of chemicals. Note that the fruit above, below, inside and outside the canopy should be evenly spread, and if it rains heavily after spraying, the spray should be replenished in time after the rain.

5.Handle the green skin.

After the walnut fruit is peeled off the green skin, it should be treated in time and buried deeply. Because there are some walnut levator moth larvae or black disease bacteria in the walnut skin, they should be collected from the walnut tree in time and buried deep together, and the place where the skin is removed should be treated with chemicals in time.

It is likely that the fertility of the soil is not enough, or it may be due to the unsuitable temperature, or it is affected by pests and diseases. The symptoms are that the walnuts turn black and rot. In normal times, we must learn professional breeding techniques, ensure sufficient light, and do a good job of drainage and ventilation.

This is because of the cause of pests, so this situation will occur, which will lead to fruit rot, will cause problems inside the husk, will lead to shriveling, be sure to spray pesticides in time, pay attention to the cleaning of weeds.

Walnut Black Spot Symptoms Walnut black spot is also known as black rot. It is mainly harmful to young fruits and leaves, and can also be harmful to young branches. The young fruit is infected, and the fruit surface has small brown spots, the edge is not obvious, and then it turns black and deep to the pulp, causing the whole walnut and kernel to turn black or rot and fall off.

After the near-ripe fruit is infected, it is first confined to the exocarp, and then spreads to the mesocarp, causing the diseased part of the peel to fall off, the endocarp is exposed, and the kernel is intact. Leaf infection, first on the leaf veins appear nearly round or polygonal small brown spots, expand and heal with each other, the periphery of the lesion is water-stained halo, a few perforations in the later stage, the diseased leaves shrink and deform.

Pathogenesis ]: Pathogenic bacteria overwinter in branches or buds. In the following spring, the bacterial fluid is transmitted by wind and rain, and invades from stomata, skin pores, nectar glands and wounds, causing infection of leaves, fruits or shoots.

Under 4 30 conditions, the host epidermis is moist and pathogens can invade leaves or fruits. The incubation period is 5 to 34 days, and in the field it is mostly 10 to 15 days. Walnut flower stage and susceptible to disease, rainy summer disease is serious.

Wounds caused by walnut limb moths are susceptible to infection by the fungus.

Control methods] :(1) timely control of walnut pests. (2) Spraying 4000 times of Bordeaux solution or 72% agricultural streptomycin soluble powder and 400,000 units of penicillin potassium salt are also effective for diluting water into 5000 times when walnut leaves are spreading and after flowering.

Walnut fruit blackening want to prevent and control, you need to use drugs to spray in time at the beginning of the disease, in the rainy season, to drain the walnut plants in time, overwintering, you need to remove the dead branches and weeds in the walnut orchard, and the soil should be regularly sprayed in places with serious pests and diseases, so as to reduce the probability of walnut fruit blackening.

If you want to prevent walnuts from turning black, then I don't think this is possible. Let him be hunted in the sun, so that it should be possible, and it can be kept in a low temperature environment, which should prevent it from turning black.

To prevent walnuts from darkening, you can apply a layer of oil wax to the surface of the walnuts, or put some other layers or something.

To prevent walnuts from turning black, they should be sealed and stored. Try not to come into contact with hot, humid air. Then you want to prevent insect infestations.

Refrigerate or take it out to dry it so that the walnuts don't get wet.

When the walnuts turn black, you just dry the walnuts and store them in a confined space for as long as possible, and don't let them be put in a humid environment, it should be okay, right?

If this ** black walnut turns black, to prevent the walnut from turning black, you will dry the walnut and store it in a clean and sealed environment, and then it should be okay in an environment, right?

1. What is the disease of walnut tree black fruit and how to treat it: walnut anthracnose: usually occurs in July and August, after the fruit is violated, there will be black-brown round, irregular lesions, it is necessary to clean up the diseased fruit in time, and enhance the ventilation of good defense friends, appropriately reduce humidity, and spray mancozeb, chartrane, anthrax Fumei and other stove with agents.

2. Walnut bacterial black spot disease: the disease is a fungal infection, the summer rainfall is sufficient and the temperature is high, walnuts are susceptible to disease, and the management needs to be strengthened.

Hello dear, happy to serve you, hope to help you. According to my inquiry: the blackening of walnut fruit is mostly infected with bacterial black spot disease, and the diseased fruit should be cut off in time, and sprayed with Bordeaux liquid and carbendazim, and used once a month to use continuous medicine according to the disease situation.

It is also possible that the poor shed is infected with canker disease, and the management should be strengthened, the trunk should be painted white to prevent sunburn and frostbite, the disease chain should be partially scraped, and the 3 Baumé stone sulfur mixture or copper sulfate solution should be used for prevention and control.