Effective methods to prevent premature aging in the late growth stage of cotton
How to prevent premature aging in the late stage of cotton? Here are the methods. The internal cause of premature aging in the late stage of cotton is that after cotton growth enters August, the demand for nutrients among roots, stems, leaves, and bolls comes into fierce competition, leading to an imbalance between nutrient supply and demand; the external cause is insufficient water and fertilizer in the cotton field in the late stage, such as phosphorus deficiency or...
How to prevent premature aging in the late stage of cotton? Here are the methods
The internal cause of premature aging in the late stage of cotton is that after cotton growth enters August, the demand for nutrients among roots, stems, leaves, and bolls comes into fierce competition, leading to an imbalance between nutrient supply and demand; the external cause is insufficient water and fertilizer in the cotton field in the late stage, such as phosphorus deficiency or potassium deficiency; some cotton fields also suffer because of too many pesticide sprays in the late stage, or excessive pesticide concentration, which causes serious damage to cotton leaves.
It should be pointed out that the fundamental measure to prevent premature aging of cotton is to start with strengthening the basic construction of the cotton field, namely deep plowing and fine harrowing of the cotton field, increasing the application of organic fertilizer, and maintaining a balance of various soil elements. After cotton enters the late growth stage, only the following remedial measures can be taken:
1. Fertilizer and water management: Apply flower and boll fertilizer heavily according to seedling conditions, climate, and soil conditions. If the flower and boll fertilizer is insufficient, then supplement with topping fertilizer. After mid-August, if the maximum field water holding capacity is below 60%, and in early September is below 55%, water promptly to promote fertilizer with water and ensure that the fertilizer effect is exerted in time. If cotton premature aging is caused by soil potassium deficiency, while applying base fertilizer, increase the application of potassium sulfate or potassium chloride by 5-10 kg during the seedling and bud stages. When applying fertilizer, be sure to plow deeper than 20 cm, apply the fertilizer at the bottom of the furrow, achieve deep fertilizer application, promote root penetration downward, reduce fertilizer loss, and improve fertilizer use efficiency. In case of drought during the flowering and boll-setting stage, irrigate lightly, carefully clean the ditches and beds, and prevent waterlogging damage again; in case of waterlogging, drain promptly.
2. Rational chemical regulation: To prevent early growth of plants from causing premature aging, comprehensively consider the timing of chemical regulation and the dosage of mepiquat chloride according to climate, soil fertility, and plant appearance. Generally, at the 8-leaf stage, bud stage, early flowering stage, full flowering stage, and after topping, spray regulators such as mepiquat chloride in small amounts several times to achieve the purpose of rational regulation.
3. Foliar topdressing: After August, for cotton fields deficient in phosphorus and potassium, spray 300-500 times diluted potassium dihydrogen phosphate solution once every 10-15 days, spraying 60-80 kg per 667 sq m (1 mu). For cotton fields deficient in nitrogen, spray 200 times diluted urea solution. For foliar topdressing, it can be sprayed all day on cloudy days, while on sunny days it should be sprayed in the evening to avoid burning the leaves.
4. Break up surface compaction: After rain, for cotton fields that have not closed the rows, especially in hilly areas, loosen the soil promptly to break up surface compaction. Do not loosen the soil too deeply, so as not to damage the root system or destroy the ridging. You can also spray the soil conditioner "Mianshengeng". Spraying "Mianshengeng" can break up surface compaction, loosen the soil, and improve soil structure; it can fully exert fertilizer efficiency, promote normal root growth, and improve root absorption capacity. Method for spraying "Mianshengeng": use 200 ml of product per 667 sq m, dilute with 50 kg of water, and spray evenly on the ridged rows.
5. Topping and pruning: First, carry out timely and careful pruning, remove ineffective flower buds, and remove all flowers that appear after the Beginning of Autumn or after White Dew to reduce consumption. Second, for the lower fruiting branches, keep fewer fruiting nodes: keep 1 node on the first and second fruiting branches, and 2 nodes on the third and fourth fruiting branches. Once enough nodes have formed, tip the side branches early. This method can save organic nutrients and prevent premature aging of cotton in the late stage.
6. Pest control and leaf protection: The functional period of normal leaves is generally about 8 weeks, but due to damage from pests such as cotton bollworm, mirids, and red spider mites, as well as diseases such as Fusarium wilt, Verticillium wilt, and red leaf stem blight, leaves become damaged or fall off, reducing leaf function and accelerating premature aging. Therefore, pest control must be done well, disease must be reduced, and leaf function must be prolonged. In the early stage of Verticillium wilt, use 40% carbendazim 1000 times diluted solution for root irrigation (0.5 kg per plant), or use 500 times diluted fulvic acid salt solution mixed with 500 times diluted Fangsimile solution for spray control.
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