Banana Fusarium wilt is a vascular disease. The pathogen invades the duct from the root, produces toxins, and necroses the vascular bundle. Banana seedlings, running water, soil, agricultural tools, etc.
Nternal symptoms include yellow to brown lesions of pseudostems and bulbous vascular bundles, which are spot-like or linear, and run into long strips or lumps in later stages. The wooden vessel at the root turned reddish-brown, extending into the bulb, and then was dark brown and dried up. The external symptoms on Longya banana are two kinds of leaf drooping type yellowing and pseudostem base cracking type yellowing. Leaf downside-down yellowing : Specific yellowing occurs at the lower part and outer leaf sheaths of the diseased banana plant. The yellowing of the leaves first appears at the leaf edge and then gradually spreads to the midrib. The yellow part is in sharp contrast with the dark green part of the leaf. . The diseased leaves quickly drooped upside down and withered, turning from yellow to brown and withered, forming a withered leaf hanging upside down. Dehiscence at the base of the pseudostem : The diseased plant first cracks from the leaf sheath on the periphery of the pseudostem near the ground, gradually expands inward, cracks layer by layer until the heart leaf, and expands upwards, the cracks are brown and dry, and finally the leaves change Yellow, upside down or not upside down, the plants wither relatively slowly.
Planting diseased seedlings and discarding diseased plants in water ditches are the main reasons for the spread of the disease. The germs have been parasitic in the soil for a long time, several years or even 20 years.
Acidic soil is conducive to the growth of the bacteria. Poor drainage and damaged roots promote the occurrence of the disease. The peak incidence is from October to November each year. Jiaoyuan has an obvious disease center.
The pathogen of banana Fusarium wilt is Fusariun oxysporun f.sp.cubense, a fungus belonging to the subphylum Deuteromycotina, which can produce large and small conidia. Large conidia, sickle type, colorless, with 3 to 5 diaphragms. Small conidia, single or twin, ovoid or round.
Avoid diseased soil to raise seedlings, strengthen quarantine, and soil disinfection. 15% oxaxyl water or 20% dibendazole wettable powder is mixed with soil at a ratio of 1:200 to make medicinal soil and then sprinkle into the seedbed or planting hole.
Irrigate the root at the beginning of the disease When sporadic diseased plants are found, the following agents can be used:
53.8% copper hydroxide dry suspension agent 500～800 times liquid;
500～600 times liquid of 23% copper ammonia suspension agent;
20% tolclofos methyl EC 1000～1500 times liquid;
Irrigate roots with 90% hymexazol WP 1000 to 2000 times liquid, soo to 1000ml per soo, once every 5 to 7 days, for 2 to 3 times in a row.