Ministry of Agriculture issues Technical guidance on late-stage Management of Cotton production in 2014

Cotton expert guidance Group of the Ministry of Agriculture

National Agricultural Technology extension Service Center

In order to strengthen the management of cotton production in the later stage, according to the cotton production situation and climatic characteristics in different cotton areas, with the goal of protecting bolls and increasing weight, strengthen fertilizer and water management in the later stage, do a good job in disaster prevention and damage reduction, and strive to achieve high cotton yield.

I. Cotton area in the Yangtze River Basin

The cotton area of the Yangtze River Basin is in the critical period of the formation of autumn peach. All localities should make full use of the favorable climatic conditions of sufficient light and high temperature in the later stage to strengthen management and seize high yield.

(1) Scientific fattening. According to the cotton growth situation, the cotton fields with late boll setting, less bolls in the middle and lower parts and prosperous growth were sprayed with 0.3% potassium dihydrogen phosphate solution; for the cotton fields with short fruit branches at the top of cotton plants and slow growth, external fertilization should be carried out in time to promote the elongation of upper fruit branches; boron and potassium fertilizers were sprayed in time to supplement late nutrients in boron and potassium deficient cotton fields to prolong the functional period of leaves and prevent premature senescence.

(2) strengthen the management of land. One is to drain water and reduce stains. All localities should pay close attention to the weather conditions, clean and dredge farmland ditches in time, rush to drain stagnant water in cotton fields, and timely help cotton plants and loosen the soil in case of typhoon and rainstorm. The second is to wipe the buds with the whole branch. The cotton plants with excessive vegetative growth and superfluous buds should be pruned in time, the invalid branches, leaves and buds should be removed, and the over-ripe bolls in the lower part of the cotton plants should be picked and dried in time to prevent the bolls from rotting. Third, spray to accelerate ripening. According to the weather and growth situation, ethephon should be sprayed to accelerate ripening in cotton fields with late cotton, many autumn peaches and abnormal cracking and boll growth, such as boll period over 45 days, air temperature above 20 ℃ and 20 days before the first frost period.

(3) Comprehensive prevention and control. Pay close attention to the occurrence of the fourth generation cotton bollworm, the fourth generation cotton bug, Bemisia Tabaci and other pests, select the right pesticides, use them in time, and control them in the right time.

(4) timely harvest. It is suitable for normal cotton bolls to be harvested after opening bolls for 5 to 7 days, and pay attention to color classification in seed cotton harvesting, drying, packaging and other links. White flowers and dark flowers, good flowers and stiff flowers, peach flowers before and after frost, normal bolls and contaminated flowers are collected, stored and sold separately.

II. Cotton area in the Yellow River Basin

According to the cotton growth situation in the cotton area of the Yellow River basin, the late production should focus on increasing autumn peach and timely harvest, control the occurrence of premature senescence and late ripening in cotton field, and strengthen fertilizer and water management to prevent boll rot.

(1) Fertilizer and water operation. One is to spray 3% urea with 0.5% potassium dihydrogen phosphate solution or photosynthetic micronutrient fertilizer on the leaves of cotton fields with premature senescence due to de-fertilization. Second, field watering should depend on rainfall and soil moisture, late watering should not be re-opened ditches, high-yield fields and numerous farming fields should continue until the middle of September. The third is to strengthen ditch cleaning and drainage to ensure smooth drainage to prevent cotton fields from being harmed by waterlogging.

(2) Scientific management. First, the prosperous cotton field and the late stubble cotton field advocate pruning and defoliation, remove empty branches and old leaves, and prevent field depression. Second, malignant weeds such as tall weeds and dodder should be removed in time, and plants should be pushed and ridged to increase ventilation and light in the field. Third, the late-maturing cotton field should look at the sky and seedlings to spray ethephon, the suitable boll period is 40-45 days, the temperature is above 20 ℃, and the spraying time is about 20 days before the initial frost period.

(3) Prevention and control of pests. Increase the control of cotton field gray planthopper, cotton bug bug, Spodoptera litura, beet armyworm and other pests, do a good job in unified control, and reduce the probability of large-scale diseases and insect pests in cotton field caused by high temperature and drought, greedy green and late maturity of cotton plants.

(4) reasonable harvesting. First, it is appropriate for normal cotton bolls to be harvested after opening bolls for 5 to 7 days, and cotton pockets should be used for harvest. Second, harvesting, drying, packaging, storage and so on should pay attention to the color of seed cotton. In operation, it is necessary to separate white flowers and dull flowers, stiff petal flowers and white flowers, peach flowers before and after frost, normal catkins and contaminated flowers to separate collection, sun, storage and sale. Third, the drying of seed cotton site should be kept clean, harvest, drying, storage should control the "three strands" mixed with seed cotton to ensure the quality of raw cotton.

III. Northwest inland cotton area

According to the characteristics of cotton production in the later stage of this year, focusing on bowling and weight gain, to promote the development of cotton bolls in the middle and upper parts, prevent bite, rot, drying, premature senescence, greedy green and late ripening, strengthen cotton field management, pest control and pruning to accelerate ripening.

(1) Cotton field management

1. Normal cotton fields. First, water should not be stopped prematurely, and urea should be applied in combination with drip irrigation to prevent premature senility. The second is to spray urea or potassium dihydrogen phosphate foliar fertilizer depending on leaf color and leaf function.

two。 Premature aging cotton fields. First, it is necessary to ensure irrigation and postpone water shutdown, especially when it comes to cotton boll opening, the soil water holding capacity should be maintained at 55%-60% to prevent premature water shutdown. Second, boron, zinc and micro-fertilizer should be added, and potassium dihydrogen phosphate should be sprayed on the leaves in the middle and later stages to prevent premature senescence of cotton. Third, urea or potassium dihydrogen phosphate foliar fertilizer solution should be sprayed every 7-10 days for 2-3 times, which can increase boll weight, lint percentage and quality.

3. Greedy green late-maturing cotton field management. First, water control, reduce the amount of irrigation, prolong the interval of irrigation, and stop water early. The second is fertilizer control, reducing the amount of fertilizer and nitrogen fertilizer. Third, artificial pruning, removal of lateral branches and secondary growth of branches and leaves buds, can also be taken to push plants and ridges and other methods. Fourth, timely application of ethephon and other ripening agents to promote ripening, before application should carefully read the pesticide label, in accordance with the regulations.

4. Management of cotton field picked by machine. Spraying defoliant should be based on the principle of spraying an appropriate amount of defoliant. It is more appropriate to spray cotton bolls at the top of cotton when more than 80% of cotton bolls reach more than 45 days and the temperature is stable at 18-20 ℃. Defoliation ripening agents must be sprayed 18-25 days before harvest.

(2) Comprehensive prevention and control. Focus on the prevention and control of verticillium wilt, cotton bollworm, red spider and other diseases and insect pests. Attention should be paid to the mixed and rotational use of cotton aphids, cotton bollworm and other insect pests.

(3) reasonable harvest. Manual cotton picking should focus on "four points" and strictly control the mixing of "three filaments" with seed cotton; mechanical cotton picking can only be carried out when the defoliation rate of the cotton field is more than 90% and the boll opening rate is more than 95%. After the mechanical harvest, manual clearing should be carried out in time to reduce loss and waste.