Why should hormone growth regulators not be used to control excessive growth in overwintering zucchini?
For zucchini seedlings, the seedling age should preferably be about 45 days (5 true leaves). Sow seeds at a spacing of 3.3 cm between plants and rows, cover the seeds with about 3 cm of soil, and transplant at a spacing of about 10 cm between plants and rows. For seedbed temperature control, from sowing to emergence, maintain a daytime temperature of 25-28°C and a nighttime temperature of about 12-15°C. After emergence in 3 days, the daytime temperature should be lowered to...
During a survey visit to greenhouses growing overwintering zucchini, it was observed that because daytime temperatures inside the greenhouses are still relatively high, many vegetable growers are still using hormones to control excessive growth in zucchini, which leads to slow growth and in some cases even hormone toxicity. Since winter has now arrived and the day-night temperature difference inside the greenhouse is large, growers can completely avoid using hormones and effectively control excessive zucchini growth simply by managing temperature.Straw curtains have already been installed on all the current greenhouses. After fully lowering the straw curtains at night, the minimum temperature inside the greenhouse is 16°C. The nighttime temperature is on the high side, which leads to excessive growth in zucchini. In this way, when closing the greenhouse, growers do not need to lower the straw curtains completely; instead, they can control the temperature by lowering the straw curtains to two-thirds of the greenhouse or to the upper part of the front face. Alternatively, they can lower the straw curtains completely, but the upper and lower vents in the greenhouse should be properly opened to keep the nighttime temperature inside the greenhouse at about 12°C, thereby reducing the consumption of nutrients. During the day, if the temperature inside the greenhouse rises above 22°C, it should be ventilated to cool down, and it must not exceed 25°C at most. This can both effectively inhibit the vegetative growth of zucchini and promote its reproductive growth, thereby effectively controlling excessive zucchini growth.
For zucchini that have already begun to set fruit, growers can keep the daytime temperature inside the greenhouse at 20°C-22°C and the nighttime temperature at about 15°C to promote fruit development.