What to Do About Broad Bean Flower and Pod Drop? Causes and Control Measures

Broad bean, also called nandou or fodou, is a crop that serves as a vegetable, a grain, and a green manure for fodder, and it is widely grown in many regions. However, during cultivation, a large amount of flower and pod drop occurs, which affects broad bean yield and also has a certain impact on farmers' income. To achieve high broad bean yields, flower and pod drop must be addressed. Read on for the detailed introduction from Qinnong Web.

1. Causes of flower and pod drop

Climatic factors: During the flowering and pod-setting period of broad bean, if rainy weather occurs, it will lead to poor pollen development or directly affect pollination, resulting in flower and pod drop.

Insufficient nutrition: During broad bean growth, insufficient nutrition, such as a lack of nitrogen, phosphorus, potassium, boron and other elements, or excessive application of nitrogen fertilizer during fertilization, can all lead to flower and pod drop.

Waterlogged soil: During planting, too much water accumulation in the soil or relatively high humidity will lead to poor soil permeability, hindered root growth, lack of oxygen, and an inability to normally transport nutrients and water. Over time, this causes flower and pod drop and may even kill normal plants.

Excessive vegetative growth: When plants show excessive vegetative growth, with tall stems and dense leaves, ventilation and light penetration become extremely poor, causing flower and pod drop.

Diseases and insect pests: Many diseases and insect pests of broad bean can cause flower and pod drop, such as rust, red leaf blight and wilt among diseases, and aphids among insect pests.

2. Control measures

In response to the above causes of broad bean flower and pod drop, we need to “prescribe the right medicine” and adopt the best control measures.

Rational fertilization: Broad bean needs different nutrients at each growth stage. Before growth, nitrogen fertilizer is the main type; in the middle growth stage, apply phosphorus and potassium fertilizer as a top dressing to improve disease resistance; at the bud and flowering stage, according to plant growth conditions, properly spray foliar fertilizer; and at the pod-setting stage, supplement boron fertilizer to increase yield.

Drainage and waterlogging prevention: During planting, drainage and waterlogging prevention measures should be well implemented, especially in rainy seasons. Dig ditches in time to drain water, lower the groundwater level and soil humidity, and ensure normal root growth of the plants.

Pruning and topping: When plants show excessive vegetative growth, prune and top them in time. Especially during the flowering and pod-setting stages, cut off some empty branches with no flowers or pods, frost-damaged branches, diseased branches and some weak small branches to improve ventilation and light penetration of the plants. In addition, topping means cutting off the young tender stems and leaves at the top of the plant, which can control plant height and reduce nutrient consumption.

Disease and insect pest control: The main diseases causing broad bean damage are rust, red leaf blight and wilt. They can be controlled by spraying 60% thiophanate wettable powder at 600 times dilution, 70% thiophanate-methyl wettable powder at 800 times dilution, and 40% hekuling wettable powder at 1000 times dilution, respectively. Insect pests can also be controlled with insecticides.

The above are the causes and control measures for broad bean flower and pod drop brought to you by Qinnong Web. We hope they can help you. To learn more about broad bean cultivation, please keep following Qinnong Web.