Eggplant in greenhouse should guard against physiological obstacles during low temperature and low light period

[abstract]: the eggplant cultivated in greenhouse is in the period of low temperature and low light (from the beginning of December to the middle of February of the following year), and all kinds of physiological obstacles are apt to appear. The causes and corresponding preventive measures are as follows:

Young leaves yellowed, young leaves were bright yellow-white, leaf tips remained green, ferruginous stripes appeared on the middle and lower leaves, fertilizer, high humidity, acidity or excess manganese in soil, inhibition of iron absorption, etc., easy to lead to yellowing of new leaves.

* Preventive measures: after the disease, 500 times ferrous sulfate solution is sprayed on the leaves (not overweight); magnesium hydroxide and lime are applied in the field to adjust soil pH; potassium is supplemented to balance nutrition and satisfy or promote iron supply.

The flower bud is not open, the ovary is not dilated, the flower bud is not open, which affects pollination and fertilization. In the cold season, the field is short of water, the air is moist, the soil pH value is above 7.5, the availability of boron in the soil decreases; excessive lime calcium in the field can induce plant boron deficiency, which can cause the flower buds not to open for a long time.

* Preventive measures: spray 700 times borax solution or amino acid peptide pollination on the leaf surface.

The fruit is cracked, the fruit is stiff but not inflated, the sponge tissue is compact, the skin color is dull, there are white stripes, the fruit is cracked after watering, it does not grow big, and the quality is poor. The eggplant skin will crack after being watered on a sunny day. During the period of low temperature and low light, the fruit was enlarged, the absorption of nitrogen, potassium and boron increased, and the relative requirement of phosphorus was less, such as excessive phosphorus input, which affected the absorption of potassium and boron and made the fruit succulent and ossified.

* Preventive measures: phosphate fertilizer is mainly applied under the roots of seedlings at the time of planting, 2 kg of pure phosphorus per mu in the later stage, and potassium fertilizer is mainly applied in the fruiting period.

Falling leaves and fruits, lower leaves yellowing and falling off during the low temperature period. If the temperature is too low and the nitrogen and phosphorus fertilizer is applied too much, the plants will age due to the decrease of gibberellin synthesis caused by zinc deficiency. The junction of petiole and stem, petiole and fruit was separated and exfoliated due to lack of auxin.

* Preventive measures: spraying 700 times solution of zinc sulfate on the leaves of aged seedlings, or applying 1 kg of zinc sulfate per mu, or spraying zinc-rich nutrients such as green waves on the leaves to prevent falling and promoting growth.