Key Points and Methods of Soybean Growth Control Explained
During the growth of soybeans, improper fertilization, excess water, or high-temperature and high-humidity conditions can cause soybean plants to grow excessively, leading to severe flower and pod drop, a sharp decline in yield, and affecting farmers' income. So how do you control excessive growth? Let's take a look at the detailed introduction.
1. Symptoms of Excessive Growth
Generally, when soybeans show excessive growth, the leaves grow vigorously, the field is completely closed in, and air permeability is extremely poor, so growth control is needed at this point. In addition, from the appearance, if the upper leaves of the soybean are dark green and the leaf area is relatively large, while the lower leaves show some yellowing and shedding. You can also judge from the flower clusters: if there are only a small number of flower clusters on the upper part of the main stem, while there are very few flower clusters on the branches and lower part, this is also a sign of excessive growth.
2. Fertilization for Growth Control
When fertilizing, apply as little nitrogen fertilizer as possible, because the soybean root system itself has a very strong nitrogen-fixing capacity, so in rainy climates, nitrogen fertilizer must be strictly prohibited for fields that have already grown excessively. A small amount of molybdenum fertilizer can be sprayed at the early flowering stage, with a concentration of 0.1%-0.2%. For fields with poor growth, a small amount of nitrogen fertilizer can be applied and sprayed together with molybdenum fertilizer at the early flowering stage, about 5 kg per mu, and attention should also be paid to the concentration.
3. Chemical Growth Control
At present, the most common growth control measure in production is spraying paclobutrazol, which is a plant growth retardant. It can block the synthesis of growth promoters in plants and inhibit the longitudinal growth of cells. However, when using paclobutrazol for growth control, the requirements for timing and dosage are relatively strict, and it degrades slowly, which can affect the growth of subsequent crops.
4. Artificial Growth Control
Chemical growth control during the flowering and podding stage of soybeans cannot effectively stop excessive growth. At this time, artificial growth control techniques can be adopted, using methods such as leaf thinning and pinching to control excessive plant growth and increase field air permeability. In the early stage of excessive plant growth, promptly pinch and trim the leaves of excessively growing plants, but it should not be too severe. Generally, it is appropriate to pinch off 2-3 cm of the tender tip at the top of the main stem.
The above is an introduction to soybean growth control techniques. I hope it can help you. To learn more related knowledge, please stay tuned to us.