First, the symptoms of cotton leaves blight is a physiological disease. The disease usually begins at the bud stage and is the most severe disease during the period of boll opening. It mainly begins with the tip of the main stem or the branches of the fruit branches and develops from top to bottom and from the inside to the outside. The leaves appear dark green at first, and the mesophyll gradually turns from yellow to dark red. The leaves are thick and brittle, shrinking and rewinding, the veins remain green, yellow patches occur between veins, and red spots appear. Finally, the whole leaves turn yellow or Red, petiole dehydration dry, and finally fall off. Under natural conditions, different types of cotton fields show different types, yellow-leaf type and red-leaf type, and both have both, and the same leaf can also express different colors. The diseased plants are short, with little and small bells, early boll opening, and poor fiber quality. Second, the cause of the disease Cause of cotton stem blight disease heavier reasons: First, extensive cotton farming, soil compaction permeability is poor, poor cotton root development; Second, the lack of organic fertilizer in soil, especially the lack of potassium; Third, partial nitrogen fertilizer, cotton Overwhelming growth, unpleasant fields, affect the absorption of potassium; Fourth, poor irrigation and drainage in the field, long-term drought or long-term water after rain, affecting the growth of the root; five is early and early ringing, resulting in late cotton plants The premature decay of the cotton field; Sixth, bad weather conditions, long-term drought after sudden heavy rain caused the disease, long-term rain can also exacerbate the harm. Third, control methods 1. Increase potassium fertilizer, improve fertilizer efficiency. The lack of potassium is one of the leading factors inducing stem blight of cotton leaves. For soils with potential potassium deficiency or low potassium application, each layer of potassium nitrate or potassium sulphate can be applied in an amount of 10 to 15 kilograms per kilogram, and superphosphate 20 to 30 kilograms to meet the demand for potassium from cotton and adjust fertilizers in cotton fields. Matching structure, improve the utilization of nitrogen and phosphorus. 2. Strengthen management and enhance the resilience of cotton plants. (1) For prosperous cotton fields, the use of dilute amines 2 to 3 grams or 8 to 12 milliliters of auxiliaries, and 50 kilograms of water can be applied per acre, which can effectively promote its growth. (2) For soil compacted cotton fields, timely cultivator breaks ventilation to enhance soil permeability. (3) For low-lying areas, poorly drained cotton fields should promptly pay attention to dredge irrigation ditch, eliminate water accumulation in the field, and promote the growth of cotton roots. (4) To cover the mulch with cotton, it is necessary to timely remove the mulch to promote the development of the cotton root in depth. (5) Apply Miaofei lightly, reapply flower and bell fertilizer, and apply nitrogen, phosphine and potassium in combination. (6) Pruning cotton to ensure the proper application of cotton nutrients and water, and to properly remove early buds from cotton fields that lack early water and fertilizer. (7) Strengthen the prevention and control of cotton pests and diseases to ensure the healthy growth of cotton. 3. Spray foliar fertilizer to improve the absorption of fertilizers in cotton plants. In the early stage or early stage of the disease, the cotton field can be sprayed with 2% urea + 0
.2% potassium dihydrogen phosphate + foliar micro-fertilizer mixture, with the focus on spraying on the back of the middle and upper leaves, spraying once every 7 to 10 days. Apply 2 to 3 times, the control effect is better. 4. Disaster prevention and disease prevention. Severe weather is the main inducer of the disease. Therefore, it is necessary to improve the construction of drainage and irrigation facilities in cotton fields, improve the conditions for drainage and irrigation, and ensure that the water can be poured as early as possible, and that the cotton plants can grow normally.
Other Pear
Fresh Crown Pear,Crown Pear,Yellow Crown Pear
Brother International Trading Co., Ltd. , http://www.jn-food.com