How to prevent banana yellow stripe leaf spot?

Banana leaf spot is a disease caused by a variety of fungi, mainly to damage the leaves, causing banana leaves to dry up, leading to premature plant senescence, affecting the enrichment of banana fruits, and in severe cases, it can reduce yield by 30% to 50%, and the fruit quality decreases, and it is easy to rot. The severity of the disease was closely related to the rainfall and the number of fog in the current year. The disease was serious in banana orchards with excessive planting density, partial application of nitrogen fertilizer and poor drainage. Dwarf varieties are less resistant to disease.

Prevention and control methods: Remove the diseased leaves and dead leaves of the banana orchard and burn them before the beginning of spring every year to reduce the source of initial infection. During the banana growing season, it is best to remove the diseased leaves once a month.

Control planting density. There are 180 acres of dwarf varieties, 145 acres of medium varieties, and 125 acres of high varieties. Apply more potassium fertilizer and phosphate fertilizer, and do not apply nitrogen fertilizer; Timely drainage in the rainy season to reduce the humidity of the small environment of the banana orchard.

Spraying control, now one month before the bud use 25% dichloride demulsifiable concentrate 1000 1500 times liquid or 40% carb suspension 600 800 times liquid, or 75% chlorothalonil wettable powder 800 1000 times liquid whole plant spray, every 15 20 days spray 1 time, a total of 3 5 times, and pay attention to alternate medication to prevent the bacteria from producing resistance, banana leaf spot comprehensive control effect requires that there are still 6 8 green leaves when the fruit is close to the harvest period, in order to ensure that the fruit is large and the yield is high. In the field diagnosis, attention should be paid to distinguishing leaf spot diseases caused by air pollution (such as fluoride, etc.).

Clean up diseased leaves and dead leaves: For the plants with serious disease, cut off the seriously diseased leaves and dead leaves on the plants in time, remove the diseased leaves on the ground, move them out of the garden and burn them, reduce the source of bacteria, make the orchard ventilated and transparent, reduce humidity, and reduce harm.

In the early stage of the disease, after removing the diseased leaves and after the storm and rain, timely use of medication for prevention and control, spray once every 7 10 days, spray 3 times in a row. The prevention and control agent can choose 64 alum, 800 times of alum, 70 mancozeb 700 times, 77 can kill 1000 times, 25 bichlor 1000 times, etc., and the above agents should be used alternately.

FYI.

First, the soil is not comfortable.

1.Reason: If bananas are planted in acidic soil, their growth will be affected and they will not be able to maintain the nutrients, resulting in yellowing of the leaves and susceptibility to diseases.

2.Treatment method: one is to apply soil conditioner to improve the properties of the soil at the bottom of the ridge; The second is to invest a large amount of calcium fertilizer and magnesium fertilizer, and at the same time increase the frequency of fertilization and irrigation, and expand the scope of effective improvement.

2. Excessive fertilization.

1.Why: Bananas don't need much fertilizer to grow.

If the finch is over-fertilized during cultivation, it will be too late to absorb. Excess fertilizer remains in the soil, damaging the root system and causing the leaves to turn yellow. 2.

Treatment: Stop fertilizing first, then fill the soil with water to wash away the fertilizer accumulated in the soil.

3. Disease problems.

1.Reason: The yellowing of banana leaves is mostly caused by blight, which can damage the roots and leaves of bananas, affect the normal growth and development of bananas, and make the leaves yellow and wilted.

2.Treatment method: You can choose to use a high-lead fungicide** crop wilt, and at the same time promote better and faster growth of bananas and enhance disease resistance.

Yellow leaf disease has a great impact on the quality of bananas and yield, and the pathogen can parasitize in the soil for a long time, so once infected with yellow leaf disease, the soil can not be used for the cultivation of bananas, especially for acidic soil, which is very conducive to the breeding of yellow leaf disease bacteria. 2. If there is a lack of water and lack of greenhouses, such as oxygen cultivation, the survival period of pathogens will be shortened, and if the soil drainage is poor, it will increase the incidence of pathogens. 3. If the grower finds a diseased banana plant, it should be burned immediately, and lime or formalin should be applied to the soil in the diseased hole and its surroundings for disinfection.

4. In the early stage of the disease, you can also spray 1000 times of 50% chlorizan wettable powder, or 1000 times of sulfur suspension, or 500 times of chain only 50% mixed sulfur suspension, or 50% thiophanate-methyl.