The correct method and key technical points for topping cotton
Cotton is an important textile raw material in our lives, and China is also a major cotton-growing country in the world. When growing cotton, if you want to increase yield, topping is an important measure. Topping cotton can eliminate the apical growth advantage of cotton, regulate the transport direction of water, nutrients and other substances within the plant, avoid nutrient consumption, and has an obvious effect of increasing yield and income. So when is the best time to top cotton? And how should it be done? Let's take a look together.
1. Topping time
The timing of topping is extremely important. If topping is done too early, the upper fruiting branches of the plant grow too vigorously, which can easily lead to excessive shading in the field, poor air permeability, and an increase in rotten bolls; if topping is done too late, there are too many ineffective flower buds, boll opening and maturity are delayed, and yield and quality will also be affected to a certain extent. Therefore, when topping, it must be done at the right time. The topping time should be determined based on factors such as plant growth, soil fertility conditions, the growing point, and temperature. Generally, buds that appear later need more than 80 days from flowering to boll opening. Counting back 80 days to 90 days from the first frost period is the suitable period for topping.
2. Topping method
When topping, first remove the top one leaf and one bud. When topping different plots, the weaker-growing plots should be topped first, and then the stronger-growing plots. When topping within the same plot, do it plant by plant regardless of size, and it is best to finish topping in one go, not in batches, and do not miss any plants. This is because the top is where pests gather, so removing the top tip can effectively reduce pest damage.
3. Growth control after topping
After topping, growth control should be carried out 1-2 times. The first growth control is done around one week before or after topping. For each mu, 4-5 grams of mepiquat chloride can be diluted in 30 kg of water and sprayed. This can effectively control ineffective flower buds, reduce redundant buds, shape the plant form, and increase yield per mu. The second time is about one week after the first time. At this time, increase the dosage: for each mu, 8-10 grams of mepiquat chloride diluted in 30 kg of water and sprayed. If the plants grow too vigorously, the dosage can also be increased according to the actual situation.
4. Fertilizer and water management
After topping cotton, watering and fertilizing should be done reasonably according to plant growth. Generally, 5-8 of compound fertilizer should be applied as topdressing per mu. In addition, boron should be supplemented appropriately, and 50 grams per mu can be sprayed after dilution with 50 parts water. After topping, cotton will quickly enter the peak growth period of flowers, buds and bolls. This period is also when cotton has the highest water demand, so watering should be done promptly after topping. When watering, water thoroughly with a small amount of water; it is not advisable to water too much at one time. Watering should also be done according to the actual situation to avoid causing delayed maturity due to excessive vegetative growth and affecting yield.
The above is an introduction to how to top cotton. I hope it can help you. If you want to learn more related knowledge, please stay tuned to us.