As strawberries are gradually on the market, how to improve the quality of strawberries has puzzled many growers. Many people reflect that their strawberries are not bright red and bright enough. Why is this problem? How to avoid it? Let's get to know it today!
The color of strawberry fruit is generally red, and the color of cultivated species usually varies from pink to dark red.
Red is anthocyanin pigment. The content of anthocyanin increased sharply only when the fruit was in the late stage of fruit hypertrophy, which was green in the early stage, white in the middle stage and red in the later stage.
The results showed that light had little effect on Fruit Coloration at green and white ripening stages, while temperature had greater effect on fruit coloration, but light had greater effect on Fruit Coloration at color conversion stage than temperature.
Cause of disease
(1) When the fruit is fully enlarged, its coloration is closely related to the supply of nutrients: when nitrogen is excessive, potassium and boron are deficient, the fruit is poorly colored, while mineral elements such as calcium, molybdenum and boron can promote fruit coloration to a certain extent.
(2) During the peak period of fruit enlargement, the lack of water in the fruit will also make the pericarp poorly colored.
(3) Fruit contacts with plastic film or mat grass for a long time.
(4) The coloration of fruits is generally influenced by temperature, light and soil conditions. The suitable temperature for anthocyanin formation is 20 ~25 C, and too high or too low temperature is not conducive to its synthesis.
When the temperature is lower than 5 degrees Celsius in greenhouse and the light is insufficient continuously, it is easy to produce green-headed fruits; when the light is insufficient or the sugar content in berries is low or the phosphorus, potassium and boron elements are insufficient, physiological white fruits can not be colored normally (after the berries are green at maturity, all or part of the fruits are white or pale yellow-white, with distinct boundaries, and there is often a circle of red around the white seeds. Fruit flavor, light, soft, pulp variegated (pink or white) easy to soft and rotten.
Fruit coloration is also related to endogenous hormones, and excessive use of hormones is also easy to form green top fruit.
Preventive measures
(1) Temperature should be regulated as much as possible and illumination conditions in the greenhouse should be improved.
(2) When planting, the base fertilizer should be applied with enough organic fertilizer, and the spacing between plants should be increased appropriately, so as to reduce the shading between plants.
(3) Keep the film clean, prevent the film surface from adhering to water droplets and dust, and lay Silver Ash film or aluminum foil or reflective curtain on the ground.
(4) Fulvic acid fertilizer and potassium, calcium, molybdenum and boron fertilizer were sprayed on the leaves during the coloring period. The fruit was well colored, and the early senescence of lower leaves was effectively prevented, and the harvest period was prolonged.
During fruit expansion period, timely removal of leaves that affect fruit coloration can increase coloration and prevent fruit branches from touching the ground due to overlapping, extrusion and sagging.
_Excessive application of nitrogen fertilizer will hinder the formation of anthocyanin and affect fruit coloration, so it is not appropriate to apply large amounts of nitrogen fertilizer in the later stage of fruit development; excessive application of hormones will also hinder the formation of anthocyanin, and should not be applied in the later stage of fruit development.
_10-15 days before fruit harvest in the late stage of fruit development, keeping soil dry properly is conducive to fruit coloration, so irrigation should be controlled properly before ripening stage.
(5) Adhere to timely harvesting. Generally speaking, the later the harvesting is, the better the coloring is.
_Reasonable control of temperature, humidity and light in greenhouse, breeding bees, scientific fertilization, rational application of hormones and appropriate application of carbon dioxide gas fertilizer can prevent the occurrence of malformed fruit.