How to Top Cotton? Key Points of the Latest Topping Technique
Cotton is an important textile raw material in our lives, and China is also a major cotton-growing country in the world. When planting, if you want to increase cotton yield, topping is an important measure. Topping cotton can eliminate the apical growth advantage of cotton and regulate the transport direction of water, nutrients and other substances within the plant, avoiding nutrient consumption, with an obvious effect of increasing yield and income. So when is the best time to top cotton? And how should it be carried out? 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 serious field shading and poor air permeability, resulting in an increase in rotten bolls; if topping is done too late, there will be too many ineffective flower buds, boll opening and maturity will be delayed, and yield and quality will also be affected to a certain extent. Therefore, topping must be done at the right time, and the topping time should be determined based on factors such as plant growth, soil fertility conditions, the terminal bud, 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 topping time.
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, then the stronger-growing plots. Within the same plot, topping should be done plant by plant regardless of size, and it is best to finish topping in one go rather than in batches, and no plant should be missed. This is because the top is where pests gather, so removing the top bud can effectively reduce pest damage.
3. Growth control after topping
After topping, 1-2 rounds of growth control should be carried out. The first round of growth control is done around one week after topping. For each mu, 4-5 grams of mepiquat chloride can be diluted in 30 kg of water and sprayed, which can effectively control ineffective flower buds, reduce redundant buds, shape the plant form, and increase yield per mu. The second round is about one week after the first, when the dosage is increased: for each mu, 8-10 grams of mepiquat chloride is diluted in 30 kg of water and sprayed. If the plants grow too vigorously, the dosage can be increased further according to the actual situation.
4. Fertilizer and water management
After cotton topping, watering and fertilizing should be done reasonably according to the growth of the plants. Generally, 5-8 of compound fertilizer is applied per mu as a top dressing. In addition, boron should be appropriately supplemented, and 50 grams per mu can be sprayed diluted in 50 parts water. After cotton topping, it quickly enters 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 rather than too much at one time, and watering should also be suited to investment according to the actual situation, so as to avoid excessive vegetative growth and late maturity, which would affect yield.
The above is an introduction to how to top cotton. We hope it can help you. To learn more related knowledge, please stay tuned to us.