Disease and Control of Rice Blight
symptom Also known as rust, commonly known as seedlings, sit naked. There are the following three types: (1) Absent-type erythrophoresis occurs before childbirth, the incidence at the end of childbirth is obvious, the diseased plant is short, the growth is slow, the tillering is reduced, the leaf blade is long and weak and drape, and the lower leaf is from the leaf tip. The extension of the rim to the base becomes tan and produces auburn or dark brown spots or streaks. In severe cases, the ruddy brown leaves from the tip of the plant, and only a few new leaves of the whole plant are green, like a fire. The roots are tan and brown, and the roots are short and small. (2) Phosphorus-deficient forms of red chrysanthemum often occurred in 3-4 weeks after planting, and they were able to recover on their own, and the booting period recurred. At the beginning, there are brown spots on the lower leaf tip, gradually yellowish and brown inside, and yellow ribs. The roots are brownish and mixed with black roots and rot roots. (3) Poisoning type dry red slowly after transplanting, plant type short, very few tillers. Black or dark brown roots, few new roots, born roots at the festival. The ribs of the leaves were yellowed initially, then peripherally yellowed, and the heavy leaf sheaths were also yellowed with auburn spots. The leaves were red-brown and dead from the bottom, and the whole plant died in severe cases. Etiology Potassium deficiency and phosphorus deficiency are physiological. Potassium deficiency in rice plants was severe during the tillering period. When the potassium-nitrogen ratio (K#O/N) dropped below 0.5, auburn spots appeared in the leaves. Occurred in shallow sandy soil, red and yellow soil and leakage of water, when the temperature is low when the tillering also affects the absorption of potassium, resulting in potassium deficiency. Phosphorus-deficient red chrysanthemum produces cold paddy fields on red, yellow and yellow soils, which are generally deficient in phosphorus and have a low temperature for a long time, affecting root absorption and causing severe disease. Poisonous red sand mainly occurs in paddy fields with long-term soaking, thick mud layers, and poor soil permeability, such as excessive green manure, unfermented organic manure, low temperature during transplanting, slow decomposition of organic matter, increased temperature, and lack of oxygen in the soil. Decomposition of organic matter produces a large amount of toxic substances such as hydrogen sulfide, organic acids, carbon dioxide, and biogas, which make the roots of the seedlings unstable. As the soil becomes heavy, the rice seedlings are difficult to root and increase the degree of poisoning. Control methods (1) Improve the soil, deepen the tillage layer, increase the organic fertilizer, improve the soil fertility, and improve the soil aggregate structure. (2) Potassium fertilizer should be applied early, such as potassium chloride, potassium sulfate, plant ash, potassium and calcium fertilizer. Phosphorus-deficient soils should be applied early, with concentrated application of superphosphate in an amount of 30 kg per 667 m2 or spraying with 0.3% potassium dihydrogen phosphate solution. Avoid applying single fertilizer nitrogen fertilizer, otherwise it will increase the incidence. (3) Renovate low-lying paddy fields and do a good job of drains. Green manure is a base fertilizer and should not be excessive. Plowing should not be too late. The application of organic fertilizer must be decomposed and applied evenly. (4) Early rice should be irrigated with shallow irrigation and timely paddy fields should be added to increase soil permeability. (5) The diseased paddy fields should be drained immediately, and lime should be given as appropriate, and the paddy field should be placed on a mild scale to promote the sedimentation of floating mud to facilitate the early development of new roots. (6) In the rice booting stage to the grain filling stage, the multi-functional high-efficiency liquid fertilizer Wanjiabao 500-600 times liquid was sprayed every 15 days. Spice Novelties Co.,Limited , https://www.wholesale-adult-toys.cn