What are the symptoms of banana leaf spot?

What are the symptoms of banana leaf spot? Please introduce two common kinds of banana leaf spot, namely, yellow stripe leaf spot and black stripe leaf spot. In the past two years, it has occurred frequently in banana orchards. The damaged area of banana leaves often accounts for 20%-40% of the total leaf area, and in severe cases it reaches more than 80%. Most of the leaves of diseased plants are withered and die, and the plants are unable to spike and bear fruit, or the ear and index of fruit become smaller, resulting in a great decrease in yield and a decline in fruit quality. in serious cases, the yield can be reduced by more than 50%. At the initial stage of the disease, yellow stripe leaf spot appears on the upper surface of the third or fourth young leaf at the top of the plant, and the disease pattern extends longitudinally parallel to the leaf vein to form yellowish green or yellow stripes, then the stripes expand to form dark patches, appear water stains, turn brown or rust red in the center, the edges are surrounded by yellow halos, and then the central tissue of the plaques or stripes dries up. When the disease is serious, multiple disease spots or stripes merge with each other, the surrounding tissue is necrotic, and the leaves become black and dry in a large area and die quickly. The black streak disease initially appeared between the veins on the lower surface of the fully unfolded third or fourth young leaf, with small faded green spots. The spot expands into rust-brown stripes, then deepens to dark red, brown, or black. Seriously damaged leaves, disease spots or stripes fusion, resulting in a large area of mesophyll tissue damage, become black and water stains, and finally the diseased leaves quickly die, dry, droop, and hang upside down on the pseudostem. Leaf spot disease is a fungal disease, which is easy to be prevalent under the weather conditions of high temperature and humidity, especially after typhoon and rainstorm. The disease is most common in banana orchards with close planting, no removal of buds, poor soil drainage, overgrown weeds around banana orchards, poor management, partial application of nitrogen fertilizer and poor ventilation. Click to get more banana planting techniques click to get more fruit planting techniques