What are the causes of flower and pod drop in sword beans and what preventive measures are there?

Many friends have surely eaten sword beans, and quite a few people grow them, but many friends often find that their sword beans drop flowers and pods during the growing process. What causes this? How can it be prevented? Let's find out together.

I. Causes of flower and pod drop in sword beans

1. Unsuitable temperature

Flower and pod drop in sword beans is closely related to high and low temperatures. The optimal growing temperature is between 20-25 degrees. Before flowering, if temperatures above 28 degrees occur, flower drop is very likely, and above 30 degrees the flower drop worsens, with the flower drop rate reaching more than two-thirds above 35 degrees.

2. Poor nutrition

In the early flowering stage of sword beans, because the bean seedlings grow leggy, vegetative growth and reproductive growth compete for nutrients, causing flower and pod drop. During flowering and podding, sword beans have a strong demand for light. If planted too densely, it often causes branches and leaves to shade each other, reducing the accumulation of assimilated substances, which leads to a marked decline in the plant's stress resistance, long-term nutritional deficiency in flower organ development, and severe flower and pod drop.

3. Unsuitable temperature

Sword beans are afraid of drought and avoid waterlogging. During flower bud differentiation, hot and dry weather can cause acute division of pollen cells, making the anthers infertile or dead and causing flower drop. In rainy weather, improper drainage and waterlogged soil affect pollen dispersal and cause massive flower drop.

II. Preventive measures

1. Scientific watering

Water is an extremely important condition for the growth and development of sword beans. Improper watering can easily cause flower and pod drop and reduce yield, so watering should follow the principle of "water the pods, not the flowers" - that is, during flowering, do not water too much or too forcefully, which can avoid excessive watering causing flower drop, and after podding gradually increase the amount of watering.

2. Reasonable dense planting

The sowing density of sword beans varies by variety and growing season. Generally, for vining varieties, the row spacing is 65-80 cm and the hole spacing is 20-25 cm; for dwarf varieties, the row spacing is 30-40 cm and the hole spacing is 25-30 cm.

3. Scientific fertilization

Sword beans have a long growth cycle and flower and pod at the same time, so when fertilizing, the base fertilizer should be applied sufficiently and topdressing should be frequent. The base fertilizer should be mainly organic fertilizer, with a reasonable combination of nitrogen, phosphorus and potassium fertilizers. After the first harvest and at the mid-podding stage, apply topdressing 1~2 times each, and later if the plant growth is weak, apply topdressing once.

4. Chemical control

You can spray the sword bean flower clusters with naphthaleneacetic acid and naphthoxyacetic acid, once every 7-10 days, which can significantly reduce flower and pod drop.

  The above is an introduction to the causes of flower and pod drop in sword beans and preventive measures. We hope it helps you. To learn more related knowledge, please stay tuned to us.