What are the causes of soybean green-stem syndrome and its prevention methods

Soybean green-stem syndrome is a phenomenon that occurs when soybeans enter the maturity stage, and it can seriously affect soybean yield and quality. So what causes soybean green-stem syndrome? How should it be prevented? Follow the editor to learn about the causes of soybean green-stem syndrome and its prevention measures.

I. Causes of soybean green-stem syndrome

1. Improper variety selection

Different soybean pod-setting habits lead to different degrees of green-stem syndrome. Varieties with indeterminate pod-setting habits develop green-stem syndrome more severely, whereas varieties with determinate pod-setting habits develop it more mildly. This is because determinate pod-setting varieties shift to reproductive growth after vegetative growth reaches a certain point, while indeterminate pod-setting varieties carry out vegetative growth and reproductive growth simultaneously, making them highly prone to green-stem syndrome when nitrogen fertilizer is applied excessively.

2. Improper climate and environment

Under continuous cropping and repeated planting, severe pests and diseases can affect the reproduction of soybean rhizobia, reducing their nitrogen-fixation capacity. Under repeated planting, vegetative growth and reproductive growth become imbalanced, resulting in green-stem syndrome. The flowering and podding stage of soybean is the peak period of water demand. Water shortage at this time can affect normal flowering and podding, delay normal reproductive growth, and cause vegetative growth to remain green and late-maturing. High temperatures during the flowering stage can affect pollination of the plants, forming blighted pods. Soybean itself is a short-day crop, so if the light period is too long, flowering will also be delayed, leading to green-stem syndrome.

II. Prevention measures

1. Reasonable irrigation

If drought and poor soil moisture occur before soybean sowing, watering the subsoil before sowing can ensure timely sowing and lay a solid foundation for high yield. During the soybean seedling stage, that is, within 15 days after emergence, keeping the soil slightly dry can encourage roots to grow downward and prevent lodging later. Unless it is excessively dry, watering is generally unnecessary. From 15-35 days after emergence, watering during drought can increase plant height and promote flower bud differentiation. During the flowering and podding stage, watering during drought or waterlogging can meet the water needs of seed filling.

2. Combined use of nitrogen, phosphorus, potassium, and boron

The available boron content in soil shows a highly significant positive exponential correlation with the relative yield of soybean. For boron fertilizer application, seed dressing has the best effect, reducing the blighted pod rate by 10% and increasing yield by about 20%.

3. Pay attention to pest and disease control

From the seedling stage, attention must be paid to the occurrence of aphids, and control should be carried out early. When the aphid-infested plant rate is 20%-30% and individual leaves begin to curl, control should be carried out immediately, while also controlling spider mites, cotton aphids, dwarf virus disease, and others.

4. Apply plant growth regulators

In production, plant growth regulators can be applied to reduce the incidence of pods without seeds and correspondingly increase yield. Commonly used plant growth regulators include triacontanol, 784-1, and ABT Rooting Powder No. 5, but attention must be paid to the concentration.

The above is an introduction to the causes of soybean green-stem syndrome and its prevention methods. We hope it can help you. To learn more related knowledge, please stay tuned to us.