What pesticides to use during banana fruiting and before bagging? Read on and you'll understand
Every year from January to May, bananas from Yunnan in China, Laos, Myanmar and other regions are concentratedly marketed. After bananas set fruit, they are prone to damage from thrips, flea beetles and black spot disease. So what pesticides to use during banana fruiting? What pesticides to use before bagging?Read on and you'll know!
Classified control of thrips, flea beetles and black spot disease
Thrips are insects with piercing-sucking mouthparts that pierce and suck the sap of bananas, causing damage. Affected bananas develop raised small spines that are black in color and fall off when touched by hand. Zhao Kewei suggests that for thrips control, imidacloprid with good systemic activity can be chosen and used together with banana fruit-fattening pesticides. After bananas are bagged, imidacloprid can also be mixed into fertilizer water and irrigated together with the fertilizer water, making full use of its systemic activity to achieve the purpose of controlling thrips.
Flea beetles do not like light, often hide in the heart leaves of bananas, are active at night and gnaw on the fruit peel. As the banana fingers grow, the wounds gradually become suberized, affecting the appearance of the fingers. Zhao Kewei points out that for flea beetle control, beta-cypermethrin, lambda-cyhalothrin and the like are generally chosen.
Banana black spot disease damages leaves and fruit. When young banana fruit is infected, tiny black spots appear on the fruit surface, and in severe cases they can cover the entire fruit surface, with a clearly rough feel when touched by hand. Bananas damaged by black spot disease are commonly known as “black speckled” bananas. Zhao Kewei introduces that pesticides with relatively ideal control effects for banana black spot disease include flusilazole, difenoconazole, tebuconazole, epoxiconazole and the like. These several compounds, all belonging to the triazole class, have roughly similar properties but each has its differences. For example, during the bunch emergence and young fruit stages, it is not recommended to use or to increase the dosage of flusilazole, tebuconazole, epoxiconazole and the like, to avoid phytotoxicity caused by improper use. For controlling black spot disease on the fruit, when the banana bunch has separated into three hands and the flowers have been removed, spraying for protection can be carried out, and the products chosen must be safe for young fruit.
For plants whose banana leaves have already suffered black spot disease damage, after the young bud emerges it may very likely have already been invaded by the disease, only being in the latent period without showing symptoms. Zhao Kewei also reminds banana growers that since multiple pesticide treatments are still needed after banana flower removal, improper use during the young fruit stage can easily cause phytotoxicity. Some pesticides used normally, but accumulating too much at the curved-back areas of banana fingers, can also easily burn the fingers. Therefore, when using pesticides on banana fruit, it should be done in small amounts and multiple times.
Washing the fruit before bagging is key
Fruit washing refers to fully spraying one to two applications of fungicides, insecticides and banana-swelling-type nutrient solutions before bananas are to be bagged, so as to prevent bananas from being attacked by pests and diseases after bagging. At the same time, using some leaf nutrient solutions can help bananas reach plumpness more quickly and can also improve the color of banana peel to a certain extent.
“Pyraclostrobin (kresoxim-methyl, azoxystrobin) or chlorothalonil + difenoconazole (WDG) can achieve very good results.” Zhao Kewei recommended a fruit-washing formula. When using kresoxim-methyl and azoxystrobin, it is necessary to avoid mixing with emulsifiable concentrate products, to prevent phytotoxicity or loss of efficacy. For the nutrient solution used for fruit washing, Compo Kapock plus Compo liquid calcium can be chosen. When washing the fruit, spraying should be meticulous and uniform, ensuring that both the front and back sides of the bananas are fully exposed to the pesticide, and bagging should be done promptly after the pesticide dries.