Causes of and Control Measures for Flower and Fruit Drop in Pumpkin

During the cultivation of pumpkin, flower and fruit drop problems are often encountered, which seriously affect pumpkin yield and bring huge losses to farmers. So what causes flower and fruit drop in pumpkin? What should be done? Let's learn about the details together with the editor below.

Causes of flower and fruit drop

1. In early-maturing pumpkin varieties, the female flowers open first and there are no male flowers for pollination, so the female and male flowering periods do not coincide, resulting in the inability to pollinate normally.

2. When flowering is earlier and the temperature is lower, the female flowers develop poorly, pollen tube growth is slow, and pollination is poor.

3. Excessive application of nitrogen fertilizer or continuous rainy days cause the pumpkin to remain vegetative and gain weight, with stems and leaves growing more vigorously than the fruit, and nutrients are not guaranteed during the flowering and fruiting period, leading to flower and fruit drop.

4. Pumpkin is a cross-pollinated plant. If continuous rainy weather occurs during the flowering period, normal pollination cannot occur, leading to flower and fruit drop.

5. Excessive planting density leads to a closed field canopy and poor air permeability, which is also one of the causes of flower and fruit drop.

Control methods

1. Regulate vegetative growth and reproductive growth

When vegetative growth is excessive and there are still no female flowers after the main vine has extended to the 12th node, the apical dominance should be weakened to promote the transition from vegetative growth to reproductive growth. There are several methods. One is to change the growing point: if the main vine does not set fruit, the main vine can be cut off before the leaf node where the lowest lateral vine is borne, counting forward from the main vine; the closer the lateral vine is to the root, the better, changing fruit set on the main vine to fruit set on the lateral vine; or carry out a deeper intertillage once to cut some roots.

2. Thin flowers and fruits

Because excessive female flowers previously caused flower and fruit drop, part of the flowers and fruits can be appropriately thinned.

3. Artificial pollination

Artificial pollination is best carried out from 8-10 in the morning, when the pollen has matured. Pick a robustly growing male flower, remove the petals, and gently smear the anther on the female flower stigma. At this time the stigma secretes mucus, which sticks the male flower pollen and completes pollination. One male flower can continuously pollinate 2—3 female flowers. After pollination, cover it with a leaf to prevent rain from washing away the pollen. Bees can also be released for pollination.

4. Reasonable close planting

In order to avoid a closed field canopy, reasonable close planting should be used, generally 800-1200 plants per mu is suitable. Early-maturing varieties can be planted appropriately densely, while late-maturing varieties can be planted appropriately sparsely. This helps improve ventilation and light transmission, increases the fruit-setting rate, and can also prevent disease occurrence.

The above is an introduction to the causes of and control measures for flower and fruit drop in pumpkin. We hope it can help you. To learn more related knowledge, please keep following us.