Fungal diseases of rice are common and influential types of diseases in the growth process of rice, mainly including the following:
1. Rice blast disease: Rice blast disease, also known as rice fever, is one of the most serious diseases on rice- Pathogens overwinter on rice straw and rice as mycelium and conidia, and can be classified into seedling leaf plague, leaf plague, node plague, leaf pillow plague, spike neck plague, branch stem plague, and grain plague according to the location of the disease- The occurrence of rice blast disease is closely related to climatic conditions and the disease resistance of varieties. High humidity, foggy, and rainy environmental conditions are conducive to the occurrence and spread of the disease.
2. Sheath blight: Sheath blight is one of the common and severe diseases of rice, characterized by a wide occurrence, high incidence, heavy damage, and large losses- The pathogens mainly overwinter in rice paddies through sclerotia, which are the primary source of initial infection- Sharp spot disease is prone to occur under high temperature and high humidity conditions, especially when rice grows lush and green, and the weather is rainy, the disease is more severe.
3. Rice smut: Rice smut, also known as false smut or green smut, is a fungal disease caused by rice green fungus- This disease mainly occurs in the panicles of rice, affecting some grains on the panicles- The symptoms of rice koji disease are manifested as the invasion of pathogenic bacteria into young and tender grains during the heading and flowering stage, forming diseased grains. In the early stage, a light yellow green block is exposed at the junction of the grains, gradually expanding and eventually enveloping the entire grain shell, which is 3 to 4 times larger than that of healthy grains. The color turns dark green, the surface is smooth, and later cracks and cracks, releasing dark green powder.
4. Flaxseed Leaf Spot Disease: Flaxseed Leaf Spot Disease, also known as Rice Flaxseed Leaf Wilt Disease, overwinters on grains and straw with hyphae and conidia- The seedling stage is generally the most susceptible to diseases, mainly occurring from the tillering stage to the heading stage of rice- The symptoms of the disease include oval or elongated brown lesions on the leaves, with obvious edges and often yellow halos around the periphery. In the later stage, the central part of the lesions is grayish yellow or grayish white.
In addition to the above-mentioned major diseases, rice may also be affected by other fungal diseases, such as rice bakanae and rice kernel smut. The occurrence of these diseases is related to various factors such as climate conditions, variety disease resistance, and cultivation management measures. In the process of rice production, comprehensive prevention and control measures should be taken, including selecting disease resistant varieties, strengthening field management, rational fertilization, scientific drug use, etc., to reduce the occurrence and harm of diseases.