Why do zucchini flowers abort? Three causes explained

First, poor flower bud differentiation or poor pollination, which prevents the ovary from producing plant auxin, thus causing zucchini flowers to abort. For this situation, the method of smearing the fruit can be used to supplement auxin for the fruit, promote fruit set, and prevent flower abortion.

Second, excessively high temperatures cause flower abortion. When the daytime temperature inside the greenhouse exceeds 35°C and the nighttime temperature is above 20°C, the plants will grow excessively, making vegetative growth vigorous while reproductive growth is poor, resulting in flower abortion. Therefore, during routine management, vegetable growers should keep the daytime temperature inside the greenhouse at 20-23°C and the nighttime temperature at 13-15°C, to prevent excessively high temperatures inside the greenhouse from causing excessive plant growth and flower abortion.

Third, high planting density and a crowded, closed plant canopy cause flower abortion. When the planting density is high, the plants' ventilation and light penetration are poor, especially after the fruit is pollinated; if light is insufficient, the leaves produce insufficient nutrients, which easily leads to zucchini flower abortion. Therefore, when transplanting, vegetable growers must pay attention to the planting density and promptly remove old leaves at the base of the plants to increase ventilation and light exposure and prevent flower abortion.