Anthracnose is a long-term and widespread disease caused by fungi, covering the branches, leaves, fruits and seedlings of trees. When the disease is severe, it not only causes a large number of fallen leaves, dead branches and fruits, but also has a negative impact on the growth momentum and yield of the tree. Especially during the storage period, citrus and other fruits often rot due to the disease.
In the climate of high temperature and humidity, the orchard with poor management is easy to become a hotbed of anthrax, especially in continuous rainy weather, especially in the continuous rainy weather, special attention should be paid to the occurrence of the disease. According to statistics, the incidence of anthrax is generally between 20% and 40%, but in some protected areas, the rate can even reach a staggering 80%. For crops such as strawberries, the incidence rate is as high as 90% to 100%.
Anthrax mainly affects the leaves and fruits of fruit trees, but can also attack stems, petioles and flowers.
During initial infestation, pinpoint-sized spots form on the surface of the leaves, often with yellow halos around the edges. These spots usually start at the edge of the leaf and raise the area and gradually expand into round or oval lesions. The lesions are dark brown or grayish-white with whorl stripes, while the surface is irregularly dotted with dark dots. Over time, the lesions expand rapidly downward from the tip of the leaf, forming a ripple with blurred edges, eventually causing the diseased leaf to fall off easily.
In addition, acute anthrax can occur quickly in wet weather, forming a pink gelatinous substance, often leading to leaf wilting. Chronic anthrax, on the other hand, is similar to leaf spot.
The fruit initially appears brown or black-brown round spots, which eventually evolve to black, with a depression in the middle accompanied by brown and black spore spots. In high humidity, small black dots may appear pink bumps, and multiple lesions often appear on a single fruit at the same time, and in severe cases, they may even be connected to each other, resulting in fruit rot and dry scars. The disease usually occurs from the fruit pedicle or wound.
Anthracnose on the stems is a black round or spindle-shaped depression that can lead to plant death in severe cases, especially in strawberries. Anthracnose usually starts in the middle of the shoot and develops downwards in an oval hale brown color, gradually turning into a fusiform depression, eventually leading to the death of the shoot.
Anthrax is extremely harmful to fruit trees, and almost all common fruit trees on the market can be infected, including apples, peaches, pears, grapes, citrus, dates, bananas, hawthorns, plums, apricots, cherries, persimmons, pomegranates, walnuts, lychees, longans, mangoes, pineapples, loquats, papayas, chestnuts, pomelo, etc. In addition, most fruit and vegetable crops and garden plants are also susceptible to it.
The pathogen of anthracnose in fruit trees usually overwinters in diseased branches, leaves, fruits, and dead branches and leaves in the garden, and begins to reproduce spores after warming up in the spring of the following year. Through wind, rain and insect transmission, the fungus infects young fruits and new branches, and can be repeatedly infected many times in a year, and continues until the end of fruit harvest.
The disease usually begins after fruit setting in fruit trees, causing a large number of young fruits to rot and shed. In the south, the peak of infection is from late April to early June, while in the north it is at its peak from late May to early June. In the summer months of July and August, especially in early September, the temperature rises, the rain is abundant, and the disease resistance of fruit trees is relatively low, which is the period when diseases are at their peak, especially in the middle and late stages of fruit ripening, and the incidence of fruit trees increases significantly.
The temperature range of the disease is 13-38 degrees, and the disease is very prone to outbreaks during the hot and rainy weather from April to November. It is worth mentioning that the disease is more serious in orchards with low-lying terrain, heavy soil, poor drainage, weak trees, serious pests and diseases, and poor ventilation and light transmission conditions.
Thorough Clearance Prevention:After the winter fruit is picked, combined with winter pruning, the garden is thoroughly cleaned of diseased branches, diseased fruits, diseased leaves, stumps and shriveled fruit leaves, and burned in a concentrated manner to eliminate the source of transmission of pathogens.
Prevention at the beginning of the disease:Once sporadic diseased fruits are found in the garden, they should be removed in time to prevent the spread of germs in the garden.
Park Management Prevention:When fertilizing, we should increase the application of fully decomposed farmhouse fertilizer or organic fertilizer, balance the type and proportion of fertilizer, and pay attention to the supplement of foliar fertilizer, especially to strengthen the spraying of calcium fertilizer. In addition, according to the age, tree potential and geographical conditions, the amount of fruit hanging of fruit trees should be reasonably controlled, drainage and drainage should be strengthened, diseases and pests should be prevented and controlled in a timely manner, and strong trees should be cultivated to the greatest extent and the disease resistance of fruit trees should be improved.
Through the above effective control methods, we can better prevent and control the occurrence of anthracnose in fruit trees, and ensure the healthy growth and high yield of orchards.
Under the threat of anthracnose in fruit trees, scientific prevention and control measures are particularly important. With a better understanding of the onset and hazard characteristics of diseases, farmers can take targeted measures to minimize the losses caused by anthrax. It is only through careful care of orchard management, regular cleaning and the implementation of preventive measures that we can ensure the healthy growth of our fruit trees, as well as the quality and yield of our fruits. Growers should always be vigilant in the face of anthrax and use technology and expertise to create a strong guarantee for the long-term prosperity of their orchards.