Since May, most of the cotton fields have grown steadily, the growth process of the cotton fields in northern Xinjiang is significantly earlier than last year, the current cotton fields in northern Xinjiang are generally in the 4-8 true leaf stage, although many places in southern Xinjiang have been subjected to continuous rainfall, but the cotton seedlings have also generally entered the 4 true leaf stage to the initial budding stage, Tianshan Plant Protection has put forward some field management suggestions according to the current cotton growth situation. For your reference!
In this period of cotton field management, first of all, the cotton should be classified, that is, to distinguish whether their cotton is a strong seedling, a strong seedling or a weak seedling (zombie seedling), and know the diagnosis of seedling conditions, so that the field management work can achieve some loss.
First, the diagnosis of seedling conditions at the true leaf stage of cotton
The standard of four true leaf stage seedlings: 4 leaves horizontal, that is, the plant width (the maximum distance between the leaf tips of the two leaves) is greater than the plant height, 4 true leaves grow on a flat surface, the cotton plant is short and fat, and the ratio of plant width to plant height is 2.5-3.0. The daily growth of the main stem is 0.3-0.5 cm.
The appearance of the seedlings: the top center is deeply sunken, the leaves are fat and droopy, the leaves are dark green, and the stems are tender green.
The appearance of weak seedlings: the width of the plant is equal to or less than the height of the plant, the leaves are small, and the stems are thin.
Second, the diagnosis of seedlings at the 6-8 true leaf stage (initial bud stage) of cotton
Standards for strong seedlings: six-leaf pavilion, that is, when 6-8 true leaves, the cotton plant is in the shape of a "pavilion", narrow above and below, wide in the middle, and bright green in color. From the top, the top has two true leaves on one plane, while the lower leaves grow evenly on the stems of the cotton plant. Stretch your heart. The height of the plant is 13-18 cm, the daily growth of the main stem is 1.0-1.4 cm, and the number of leaves on the bud is 2.
Wangmiao looks: the top is deeply sunken, and the leaves are thick green.
Weak seedling appearance: cotton plant is thin and tall, and the leaf color is light.
Third, for the 2-4 leaf stage cotton management recommendations
1. Strong seedlings in the 2~4 true leaf stage are deferred and controlled according to the growth amount. The seedlings tend to be adjusted in a timely manner according to the daily growth rate, variety sensitivity, and proportion of red stems, and the specific quantitative amount is 1 to 1.5 times the daily growth amount, and N hormones and growth promotion hormones are not applied. For the affected and insect-infested cotton seedlings, appropriate water and fertilizer can be promoted, and strong seedlings can be cultivated as soon as possible.
2. The best time for cotton to promote weakness and control the management period is May 20 to 25. According to this time, strive for the growth of late weak seedlings, so that the plant height and the number of fruit branches are formed in sufficient time, and the water and fertilizer chemistry is regulated in time for the seedlings, so as to make positive preparations for timely topping and shaping in advance.
3, the head water time and others. Around May 25, the late seedlings, weak seedlings, and disaster-stricken seedlings (wind damage, cold damage, insect pests) timely water and fertilizer adjustments were carried out to accelerate the fertility process. If necessary, urea and phosphate fertilizer are provided with 1 to 2 kg, and the chemical control is reduced. Wangmiao postponed the water intake, and the control of water and fertilizer was better than the chemical control effect. Normal water-fed cotton seedlings look like two heart leaves on the bud stretched but do not form the top of the third young bud, and the chemical adjustment is carried out in 2 to 2.5 times the daily growth amount 2 to 3 days before water, generally 2 to 4 g / mu.
Fourth, field management technical measures
Promote the combination of control, promote transformation, and achieve the goal of early bud emergence and early flowering.
(1) Regulatory technical measures
It is recommended to focus on water control, delay the dripping water time, accelerate the transformation of cotton from vegetative growth to reproductive growth, and strictly prevent early head water due to the late seedlings this year, so that the flowering of buds is more delayed.
Supplemented by chemical regulation to promote transformation, it is recommended that for wangmiao or strong seedlings mu use 0.5-1.5 grams of accrylamine, accrylamine must be based on the growth of cotton, variety characteristics, planting technology and other reasonable dosage.
(2) Cultivate the soil and raise the ground temperature
Adhere to the principle of ploughing after rain and more grass, and improve the ground temperature, promote root growth, and cultivate strong seedlings through medium cultivation to disperse moisture. Especially in weak seedlings or zombie seedling fields, it is necessary to increase the number and depth of cultivation.
(3) Foliar fertilization, mainly to promote
For weak seedlings or zombie seedlings, cotton leaf fertilization can be carried out with 200 grams of urea plus 150 grams of potassium dihydrogen phosphate per mu. It can also be used as appropriate to promote the growth of amino acids, amino oligosaccharides, red, indigo, brassica, brassica lactone and other seedlings.
(4) Prevention and control of diseases and insect pests
The main investigation is the occurrence of cotton aphids, leaf mites, cotton blind bugs and cotton bollworms, adhere to the standard prevention and control, for the blind bug leaf breaking rate of more than 10%, timely application after 4 true leaves; timely drug control for cotton aphids and cotton leaf mite central plants.
A family's words, inevitably extreme and insufficient, please refer to it as appropriate, if there are suggestions and objections, please leave a message after the text to communicate!
Photo editor: Tianshan Plant Protection, please indicate the source of the reprint!