In the early spring, cucumbers are prone to diseased seedlings, weak seedlings, and wounded seedlings, which cause serious deaths of the whole plant. According to Guo Zhiqing, a researcher at the College of Horticulture at the Northwest A&F University, the situation that caused the miscellaneous seedlings is complicated. It is mainly to do preventive work to ensure the healthy growth of the melon seedlings.
Four days after the emergence of rigid seedling seedlings, the cotyledons were dark green, leaf margins were lower, stems were short, and growth was slow. They were mostly caused by less fertilizer, less water, excessive soil viscosity, or unfermented manure.
Preventive measures: soaking water before sowing to meet the water requirement during seedling period; clay should be mixed into fine sand, deep exposure; drying; spray water or spraying foliar fertilizer to promote growth. Dwarf seedlings are dwarf, with small leaves, light shade and no light, internodes too dense, stems hardened and fine, roots are stunted, brownish. Seedbeds have poor soil quality and lack of water, especially when there is water shortage, low temperature, and lack of fertilizers.
Preventive measures: 1 Select fertile, permeable, air-permeable, soil or sandy land with good physical properties as the seedbed. The nutrient soil should be mixed with fully decomposed high-quality organic fertilizer in a ratio of 6:4, and appropriate amount of ash should be added. At the same time, to supply sufficient water, the seeds are soaked in enough water before sowing, and the relative humidity of the soil is kept at 70% to 80%. 2 The temperature needed to maintain the germination of seedlings is generally better at 22°C to 25°C during the day and 12°C to 18°C ​​at night.
Excessive seedling temperature is too high, lack of light, rainy days or grass cover early cover, nitrogen fertilizer in base fertilizer or nutrient soil, too much water, excessive density, etc. are caused by a variety of reasons for leggy seedlings.
Preventive measures: 1 When the temperature is higher than 30°C, the air is to be released, and if the temperature is lower than 20°C, the air outlet can be closed. At the same time, the night temperature can not be too high, generally grasp the first half of the night 14 °C ~ 16 °C, after midnight 10 °C ~ 14 °C is appropriate. 2 increase the light, grass cover early cover late cover, add reflective film in the studio. 3 Properly spray 25 to 50 mg/l paclobutrazol solution to control growth.
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