Ethephon can effectively promote the differentiation of female flowers in greenhouse cucumber seedlings and increase cucumber yield. However, many vegetable farmers in production practice often cannot accurately use the concentration of pesticides , causing the concentration to be too high, causing the growth of seedlings to stagnate, flower topping and formation of dead seedlings. In severe cases, the growth point is dry and dead. In this regard, the following remedies can be taken:
Strengthen fertilizer and water management. After the occurrence of phytotoxicity, according to the degree of phytotoxicity, increase the application of quick-acting nitrogen fertilizer and increase the number of irrigation to ensure sufficient water and fertilizer supply.
Spray gibberellin. Cucumber four leaves and one heart stage have ethephon treatment, the concentration of more than 200 mg / liter is the occurrence of phytotoxicity, at this time can be sprayed with 20 ~ 50 mg / liter of gibberellin solution. When using, first dissolve it with alcohol or white wine and then prepare it according to the concentration, and spray it as soon as possible after the symptoms of phytotoxicity appear. Spray the second time after a week, and generally return to normal after about 15 days.
Increase the temperature inside the shed. The suitable temperature for normal cucumber seedlings during the day is 25-28 °C and 13-15 °C during the night. After the damage, the shed temperature should be increased to 30 °C during the day to promote the growth of the seedlings; the original low temperature can be maintained at night to ensure the continued differentiation of the female flowers.
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