Bananas are one of the most common fruits in our lives, and throughout the year, the major supermarket fruit stalls will never be indispensable to its presence. Everyone should know this saying, "One apple a day, the doctor is far away from me", this sentence fully reflects the nutritional value of apples. And bananas are no less than apples. It is rich in a variety of nutrients, such as vitamins, proteins and various trace elements necessary for human development and growth, which can increase appetite and promote digestion. Moreover, the low price of bananas, the soft and sweet flesh, and the melting in the mouth have made it a favorite fruit of every household. Bananas can be peeled and eaten, but sometimes people also choose to use it to make fruit salad, peel it and cut it into small pieces, pour in yogurt, stir well, it is a delicious dish, this salad can be said to be the best choice for weight loss. In fact, bananas appeared very early, according to historical records, when Emperor Wu of the Han Dynasty built the Fuli Palace, he searched for strange flowers and plants in the world, including bananas. Bananas also have a name, "fruit of wisdom", because there is a legend that Shakyamuni ate bananas before he began to have an epiphany, and finally gained the wisdom of the Buddha.
Although many countries in the world are growing bananas, China can definitely be said to be the "ancestor". China's banana cultivation is mainly distributed in the southern region, such as Guangxi, Guangdong, Yunnan and other places. There are many types of it, the more common ones are QiWei, Xian Xian Banana, Williams, Tianbao Banana, Guangxi Dwarf Banana. Among them, Qiwei and Xianren bananas belong to high-dry type fragrant bananas, which are excellent varieties, and the bananas produced are of better quality and easy to store, but the wind resistance and cold resistance of the plants are poor, and the requirements for the environment where they grow are very high. Williams belongs to the medium-dry type of tooth plantain, the yield is good, and the wind resistance of the plant is stronger than that of the high dry type. Of course, no matter what kind of bananas are planted, if the banana farmers do not take care of them, they will suffer from diseases, common diseases such as bunch top disease, black star disease, black spot disease, and heart rot. Although these diseases are common, the harm is more serious, if the banana disease is not treated in time, it will definitely reduce production or even get nothing.
Now at the turn of summer and autumn, the temperature drops and the rain increases, creating a low temperature and humid environment, which can easily cause black star disease. So today we will come together to understand the black star disease of bananas, the following will be for you to elaborate on the symptoms of the disease, infection conditions and its prevention and control technology.
<h1>I. Introduction to banana scabies</h1>
Of all the diseases that bananas are susceptible to, black star disease is one of the more serious. Black star disease can occur at any time of plant growth, whether it is the initial budding period, flowering period, or later growth period. It is mainly harmful to the leaves and fruits of bananas, and is very contagious, may start with only a small leaf or a fruit, if not treated or cleaned up in time, it is likely to cause a large number of diseases in the later stage, and in severe cases, it will directly cause banana deaths, so that the income of banana farmers is seriously damaged. And the black star disease of bananas is more difficult to treat, so it should be prepared for prevention.
<h1>Second, the pathogen of banana black star disease</h1>
Banana black star disease is a fungal disease. It is triggered by a pathogen called banana large-stemmed spot fungus, and the residual leaves of the dead branches and dead plants after the banana garden is picked are their best parasites and the largest source of banana black star disease bacteria. Of course, they may also attach to the soil and the support of bananas. These germs live on it in winter, ensuring their own survival and may also produce spores. After winter has passed, they will choose the right time and climate to spread around in the form of conidia, and then quickly infect the leaves, flowers, stems, and fruits of the plant, invade its epidermis, and begin to develop diseases. At this time, the reproduction of the germs is still not over, the infected part becomes their host, using it as a breeding ground, continuing to grow a large number of spores, rapid infection, and soon after, the entire banana garden will be sick.
<h1>Iii. Transmission routes of the banana scabiniton disease pathogen</h1>
Like most fungal diseases, the pathogen of black star disease is also transmitted by wind and rain. In the autumn, this windy and rainy season is the most conducive to the spread of germs, the conidia of the fungus are blown by the wind, it is very easy to drift from the plants in one place to the plants in another place, so that the spread of the disease is rapidly expanded and the speed of spread is also very fast. During the rainy season, germs in the rain-splattered soil are likely to be splashed on the leaves and then splashed on various other parts, and what's more, the spots on the leaves are the same as the paths on which the rain flows. Of course, if germs want to invade the plant, they need an "entrance" to enter the plant from the outside, usually, they create this entrance themselves, but if the plant itself has a wound, it will make the invasion of the bacteria more smooth, and it will also make the disease more serious and more difficult to manage.
<h1>IV. Symptoms of banana scab disease</h1>
The leaves, stems and fruits of bananas are the most susceptible to black star disease, and the occurrence of disease is possible at every stage of plant growth.
1. Leaves: When the banana has just grown new leaves, the new leaves begin to appear in the infected place, most of these spots are round, some are irregular in shape, and the spots are yellowish, and then the leaves begin to wither, from the above spots began to shrink, after a period of time, the whole leaf died. If it is not treated at this time, the new leaves of the entire banana plant will face the consequences of withering, and if none of the leaves of the plant survive, then it will not be able to grow or will die. If it occurs in the leaf-forming stage of the plant, the leaves at this time are infected, and at the beginning, like the new leaves, a circular pale yellow spot appears, and then the area of the lesion continues to expand, the color also deepens, becoming dark brown, and forming a halo of pale yellow around it. At the veins or edges of the leaves, the spots are linear. Soon after, the lesion began to perforate, destroying the leaf veins, and the leaves around the hole began to shrink inwards, and finally died.
2. Stem: After the stem of the banana is infected with the disease, there are strips or irregular spots, the color of the spots continues to deepen in the later stage, and the disease begins to sink downwards, and the liquid flows out, and soon the stem will begin to rot, the stem rotting plant will not be able to absorb nutrients, and the plant will grow poorly or die directly.
3. Fruit: fruit infection, in the banana bend and on the epidermis will appear a large number of brown spots, at first these spots are only round or striped dots, and then the spots will become larger, if this is not yet cured of the disease, then in the process of fruit continue to grow, the disease will continue to aggravate, the fruit surface appears a large black spot, and the spot at the fruit becomes soft and rotten, immediately there will be a layer of black mold covering the disease.
<h1>V. Pathogenesis of banana black star disease</h1>
1. Low temperature humid climate
The most suitable environmental conditions for the incidence of black star disease are 17 degrees Celsius and 90% humidity, which is a typical low temperature and high humidity climate. Autumn temperatures are low and rainy, making the banana orchards wet and not dry. As we all know, humid climates are more likely to breed germs, and in such an environment, the survival and reproduction of germs is easier, which makes black star disease can spread rapidly. If you accidentally cause a wound in the event of a storm, it will provide an opportunity for germs to invade. And most of the spread of germs requires the use of some medium, and rain is an excellent choice for them. They spread everywhere with the rain, ravaging banana orchards.
2. Improper management of banana orchards
Soil is a necessary condition for plant growth, if the soil of the banana garden is not taken care of, the soil is lumpy, the roots of the plant can not draw sufficient nutrients from the soil, and even affect the respiration of the roots, resulting in root rot. In addition, if the drainage of the banana garden is inconvenient and the ventilation is poor, then after the rain, the low-lying part of the banana garden forms water, and its environmental conditions are not conducive to the discharge of the water, and the environment of the banana garden will naturally become humid and induce disease damage. Finally, some banana farmers do not pay attention to the density between plants when planting, so that some overly luxuriant plant branches are entangled with each other, which is not conducive to their own growth.
3. The cleaning of diseased branches and leaves is not timely
If the diseased branches and leaves left in the banana garden after the annual harvest are not cleaned up, there will be pathogens parasitic in them, waiting for the opportunity to infect the plant in the coming year. Of course, the same is true of the already diseased branches and leaves, which are more likely to spread germs.
<h1>Prevention and treatment of banana black star disease</h1>
1. Agricultural control
1) Choose the right variety: On the one hand, in the selection of banana varieties, on the one hand, we need to consider the location of the planting place, different regions have different environmental conditions, different environments are suitable for different varieties, so we must choose the most suitable varieties for the local environment to plant, so as to maximize the benefits; on the other hand, we need to consider the disease resistance of the varieties, the stronger the disease resistance, the easier it is to avoid diseases and thrive.
2) Soil management: There are a large number of germs lurking in the soil of banana orchards, they are waiting for opportunities, ready to infect plants, so it is necessary to disinfect and sterilize in advance before planting every year to reduce the source of disease, thereby effectively reducing the probability of disease occurrence. In addition, in order to prevent soil agglomeration from affecting plant growth, it is necessary to loosen the soil before planting, mash the soil block, improve the air permeability of the soil, and help the development of plant roots.
3) Water and fertilizer management: Adequate water and fertilizer are indispensable conditions for banana growth, and only when the plant fully absorbs nutrients can it grow vigorously. Therefore, during the growth period of plants, it is necessary to strengthen the water and fertilizer management of banana orchards. Fertilize the banana garden periodically, but it should be noted that the daily irrigation amount should be moderate, otherwise it will cause the banana garden to be wet, of course, in order to avoid dampness, it is best to water during the day. Fertilization is the same, you can not apply too much nitrogen fertilizer, you can mix organic fertilizer with phosphorus and potassium fertilizer.
4) Clean up the banana garden: After the bananas are ripe and picked, the remaining branches and leaves in the banana garden should be cleaned up in time to reduce the source of disease and prevent them from rotting and attracting germs. At the same time, it is also necessary to regularly check whether the plants in the banana garden are infected, once it is found, the diseased parts on the diseased plants should be cut off to eliminate the possibility of infection, and the collected stumps and diseased leaves should be either buried or burned, and sprayed around the diseased plants to prevent the disease of the plants around it in time.
5) Fruit bagging: When the banana fruit is ripe, it can be bagged, the fruit is wrapped with plastic film, the bag mouth is down, which is convenient for fruit breathing, and another layer of fiber film can be added under the plastic film. Doing so prevents germs that spread due to rainwater splashes from attaching to the fruit surface during the rainy season.
2. Chemical control
1) When bananas are not yet infected by the disease, chemical agents can be used to prevent the occurrence of black star disease. Commonly used agents are: 50% Gaomei Shi 300 times liquid, 60% spray Shi Bao 300 times liquid, 45% polygonal hormone 200 times liquid, etc., sprayed on the leaves and fruits, can increase their disease resistance.
2) When bananas have been infected, we can also use chemicals to treat them. The agents that can be used are 60% Bordeaux liquid 300 times liquid, or 70% methyl tolbuzin wettable powder 350 times liquid, or 55% daisen zinc wettable powder 700 times liquid, or 30% flusilzomid 1500 times liquid, or 45% daisen manganese zinc 200 times liquid, or 40% benoscin wettable powder 800 times liquid, or 75% kexin wettable powder 540 times liquid, 80% bacillus clear wettable powder 300 times liquid, or 40% azoxystrobin 600 times liquid.
That's all there is to know about banana scabies. Black star disease is common but harmful, and banana farmers must pay attention to prevent it when growing bananas. Before the banana disease, to strengthen the prevention, regularly check the growth of bananas in the banana garden, spray some agents, once found abnormal, it is necessary to determine the disease as soon as possible, in order to prescribe the right medicine, the earlier the treatment, the more conducive to the recovery of bananas, but if the disease is allowed to spread without taking any measures, then it is doomed to damage the interests. Of course, if the precautions are in place, then banana farmers can definitely improve the yield and quality of bananas and increase their own income.