What causes flower topping in zucchini? Cause analysis and control measures
When zucchini is cultivated in greenhouses, flower topping is very likely to occur. Once flower topping occurs in zucchini, it seriously affects yield, especially the early yield, generally reducing it by 30%-40%. So what causes flower topping in zucchini? How should it be controlled? Follow the editor to learn about it.
1. Excessive seedling hardening
Although hardening zucchini seedlings can control top growth and promote root growth, which is beneficial for cultivating strong seedlings, if the hardening period is too long, or if the soil is dry, it will cause poor nutrition at the stem tip growing point and weak growth, leading to flower topping of the heart.
Control methods: The seedling hardening time should be appropriate, and excessive hardening should be avoided. In addition, the soil should not be too dry. In the early stage of flower topping, water timely and appropriately so that the soil moisture content remains at about 20%. At the same time, apply some quick-acting nitrogen fertilizer with irrigation to promote vegetative growth of the plant, or spray gibberellin, which can also promote stem and leaf growth.
2. Low temperature
The suitable growth temperature for zucchini is about 18-25 degrees. Below 15 degrees, its growth will be poor, and below 11 degrees, growth will stop. If cold waves hit in winter and early spring, causing the greenhouse temperature to be between 11-15 degrees, or even a low temperature of 0 degrees, its growth nodes will also stop growing, leading to growth and development disorders, causing male flowers to cluster at the top and flower topping to occur.
Control methods: Temperature must be strictly controlled, especially low nighttime temperatures, so during the seedling stage and the early planting stage, the nighttime temperature should be kept above 15 degrees. When the temperature is too low, measures such as adding a layer of straw curtains around the greenhouse and building small arched tunnels inside the greenhouse should be taken. If conditions permit, smoke-free heating measures such as laying ground heating wires or installing electric stoves or burning charcoal can be used.
3. Root damage
Root damage caused by seedling raising and transplanting, root rot caused by excessive moisture, and root injury caused by excessive fertilization can also hinder the growth nodes and lead to flower topping.
Control methods: When raising seedlings and transplanting, be careful not to damage the roots too much and water appropriately. Especially in cold seasons, water lightly to prevent root rot. Fertilization should be reasonably balanced and not blindly excessive to prevent root burn. In addition, all the small young fruits on the upper part of the zucchini should be removed to reduce the burden on the plant and help the stems and leaves grow robustly. For plants with flower topping, harvest ripe fruits in time, and thin flowers and fruits for those with many female flowers or many fruits. Generally, a robust plant should retain 1-2 fruits per plant.
The above is an introduction to the causes of flower topping in zucchini and control measures. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.