To pinch off the head of the broad bean is to give it a top, the purpose is to make it grow in a coordinated manner to facilitate the extermination of aphids.

1. Broad beans, like all other plants, reach a certain age or physiological state under the right conditions, will be transferred from the nutritive growth stage to the reproductive growth stage.

2. The bloom period of broad bean is the late stage of the transformation process from nutritive growth to reproductive growth, at this stage, although reproductive growth has played a dominant role, but, nutritive growth is not stopped, the two growth properties still co-exist at the same time.

3. In production practice, in order to coordinate the contradiction between nutrient growth and reproductive growth, so that the growth situation more in line with the needs of production. So, in the flowering stage of broad beans, pinching off the top of the growth, can control the nutrient growth, and more favorable to the reproductive growth.

Two, broad bean bloom period pinch off the tender head, can reduce aphid hazard

Aphids on the plant's harm, not only sucking the plant's sap, directly affecting the plant's healthy growth, but also spread the virus. When fava beans are infected with virus disease, the leaf surface is wrinkled, the color of the leaves is faded, the leaf area is small, the growth is retarded, and the yield is seriously reduced.

The reproduction and activity pattern of aphids starts from the young parts of the plant, and, mainly distributed in the tip of the plant. Broad beans into full bloom, and pinch off the tender tip, not only is conducive to flowering and fruiting, but also to control the damage of aphids, half the effort.