What s the deal with dark spots on loquats? How to prevent it?

On the basis of supplementing the role of off-season fruits, there has been no perfect system for planting management technology, no management and planning of growers, no pest prevention in mind, no knowledge of what pests and diseases loquat has, and no measures to take to prevent such pests and diseases. Therefore, today is the first to have a fever in advance.

Deeply understand the diseases and laws of leaf spot, and summarize a series of preventive measures for your reference. In the past, leaf spot disease was mainly concentrated in Fujian, Guangxi and other provinces in China, but in recent years, due to the introduction of seedling transportation and other ways, there has been a trend of continuous spread. After the loquat in the orchard is infected with this disease, the disease spreads rapidly, and dense reddish-brown spots appear on the leaves of the plant, and in severe cases, the trees lose many leaves, the trees weaken, and the fruiting ability is greatly reduced.

Loquat leaves. Spot disease is a general term for gray spot disease, horn spot disease, and spot disease, and these three diseases often occur mixed, but the diseases and pathogenic bacteria between the three diseases are different. It is the disease that has the greatest impact on yield and quality in the current loquat production, mainly harming the buds, young leaves, old leaves, flowers, fruits, etc. of the plant, the leaf edge of the disease is semicircular, and the rest of the spots are round, and the spots ** are from gray-white to gray-yellow, and there are black spots scattered on it.

The incidence of loquat leaf spot disease is significantly increased in a warm and humid environment, and there is no fixed onset time, and it can occur throughout the year and be infected multiple times within a year. Among them, the probability of occurrence of gray spot is very low, the temperature is between 24 28, above 32 and below 20. In addition, a dry environment can promote the occurrence of macular and angular spots.

When placed on production, it is usually carried out in two periods of March-July and September-October every year.

In general, healthy leaves are not only free of spots, but they are also dark blue in color.

It is shiny and does not show any diseases. If there are spots, the leaves must have been damaged by germs. Because it is a disease, it naturally affects the normal development of trees and fruits. It is well known that leaves act as an important organ of fruit trees through photosynthesis.

The nutrients needed to produce fruit trees, if the leaves are diseased, can seriously affect the growth and development. Leaf diseases can also affect the quality and yield of fruits, as well as the growth and development of trees. So, what kind of spots appear on the leaves, and will they affect the quality of the fruit and the growth of the tree?

That's for sure, this spot is known as leaf spot. Leaf spot mainly includes gray spot disease, corner spot disease, spot disease, and original spot disease, among which the first three are the more common diseases that harm the leaves in loquat, and the gray spot disease is the most common and the most common among these three diseases. The three diseases are not a single occurrence and injury on the leaves, but often occur in combination, and the lesions are similar, which is difficult to distinguish.

Therefore, these three diseases are generally referred to as leaf spot. The occurrence of the original class disease is rare, and the symptoms of injury are the same as those of angular spot disease, which will not be introduced here, but mainly introduce the other three diseases.

1. The loquat spot pathogen mainly overwinters on diseased leaves, and spreads through wind and rain in March and April of the following year.

2. Loquat spot disease is most likely to occur in the rainy season, and it can occur many times in a year.

1. In winter, all the diseased leaves and fruits that fall to the ground will be cleaned and burned in a centralized manner.

2. After picking the fruit of loquat, cut off weak branches, dead branches, diseased branches, dense branches, cross branches and strong long branches. After a certain number of years of growth, the fruiting branches have no leaves at the base, and the branches are too long, which will affect the development and quality of fruits. After the fruit is harvested, it is shortened 10 cm from the base of the branch.

This reduces canopy closure and enhances canopy light and ventilation.

The spots on the loquat are likely to be infected with diseases, and most of them are leaf spots.

After winter, it is necessary to remove diseased leaves and fruits. It should also be pruned in time, every year after fruit picking. Drain water in time during the rainy season. In addition, it is necessary to spray the drug normally.

If there are black spots on the loquat, it can be considered as a spot disease hazard, and the disease prevention and control should be strengthened before bagging, it may be that the number of pathogenic bacteria in your orchard is relatively large, and pyraclostrobin can be used to sterilize it.

1.When the air humidity is too large, water droplets appear on the fingers before the fruit, and the light conditions are not good, it is more likely to appear black spots.

2.A small amount of dark spots is normal, this situation mainly occurs in the rainy season, if the ventilation of the fruit is poor, the branches and foliage are too dense, it is more tolerant of such problems.

1. Symptoms and hazards of loquat brown spot disease Only the harmful leaves are seen. Lesions on the leaves initially appear on the leaf surface as small yellowish spots, then turn into small brown spots, brown spots to russotic brown spots. The lesions are 1-3 mm in size and nearly round, angular or irregularly shaped.

In the later stage, the diseased part passes through both sides of the leaf, and the color of the leaf lesions fades to gray-brown, and black mold particles grow, which are pathogenic conidia and substantiae. The most distinctive feature of this lesion is a yellow halo on the outer edge, which stands out on the green leaf surface.

2. Loquat brown spot disease transmission route The pathogen of loquat brown spot disease overwinters on the diseased leaves with hyphae, and produces conidia for initial infection in the following spring.

3. Causes of loquat brown spot disease.

1.Loquat orchards have poor soil, poor drainage or moisture retention, and serious diseases.

2.There were differences in disease resistance among loquat varieties.

4. Preventive measures for loquat brown spot disease.

1.Planting disease-resistant loquat varieties.

2.In late autumn and early winter, remove diseased leaves in time to reduce the source of infection.

5. Pesticides for the prevention and control of loquat brown spot disease are sprayed with 25% benomefen, 800 times of cyclohexizin emulsifiable concentrate or 800 times of 50% thiophanate-methyl sulfur suspension, and 900 times of 50% Shibaogong wettable powder in the early stage of loquat brown spot disease.

1. Plant disease-resistant loquat varieties.

2. Remove diseased fallen leaves in late autumn and early winter in time to reduce the source of infection.

3. Pesticide prevention and control of loquat brown spot.

In the early stage of loquat brown spot disease, spray 25 benzyl and cyclohexane zinc emulsifiable concentrate 800 times or 50 thiophanate-methyl sulfur suspension 800 times, 50 Shibaogong wettable powder 900 times.

FYI.