High quality citrus can not be separated from the beautiful taste, and also can not leave a dazzling appearance. Citrus coloring is an important part of citrus cultivation.How to do it? Let's start with the coloring mechanism of the citrus.
First, The relationship between pigment and citrus color
The pigment of citrus growth is chlorophyll, carotenoid, anthocyanin. Chlorophyll is the cause of green citrus fruit. Carotenoids are yellow and even red, orange to orange, red and other ripe colors. Anthocyanin is a kind of pigment commonly found in fruit, and the color of fruit is related to it
Second, The intrinsic reason for the ripening of citrus
With the growth of citrus, chlorophyll gradually decompose, the unique background, and presents the inherent mature on background color (yellow, red), this is the internal reason turn orange color.
Third, Factors affecting citrus coloring
Accumulation of sugar in fruit: anthocyanin and carotenoids are metabolites of sugar, which are in direct proportion to the total sugar content. Only when the sugar of the citrus reaches a certain concentration, the citrus can be colored, and as the sugar increases, the color becomes thicker
2. Illumination: the external fruit is better in color than the inner fruit, and the color is heavier than the back of the back, which indicates that the light affects the citrus coloring. One of the reasons is that the photosynthetic effect of light promotes leaf, which causes more sugar to flow into the fruit, and on the other hand, the light can directly induce the production of pigment.
3. Temperature: the appropriate low temperature can increase carotenoid, anthocyanin synthesis, and help citrus coloring
4. Minerals: too much nitrogen and too much red. There is too much nitrogen in the leaves, which is beneficial to the chlorophyll growth, promoting the growth of branches, increasing the consumption of organic matter, and reducing the transfer of sugar to the fruit. Negative coloring
Phosphorus can accelerate the metabolism of sugar in the fruit, which is beneficial for pigment formation and citrus coloring
In addition to the synthesis of sugar, potassium promotes the transfer of organic matter to the fruit and resists the absorption of nitrogen
5. Plant growth regulator: It can promote photosynthesis, regulate the nutrient balance of the tree body, it is the color of the citrus and the color is good. Gibberellin(Gibberellic acid), cytokinin(6-Benzylaminopurine,BAP), reduces the fruit coloring. Ethephon, abscisic acid (S-ABA)can promote the fruit coloring. The citrus varieties that require normal growth should not use gibberellin, cytokinins and other regulators, and use ethylene to promote colouring products.
The best coloring scheme is below：
First, reasonable fertilization：Rational control of the use of nitrogen fertilizer and Potash phosphate fertilizer，The fruit trees with poor root system and weak tree potential can use plant conditioner to spray root and drip irrigation.
Second, using colorants scientifically：When the orange begins to turn color, Diethyl aminoethyl hexanoate 8% sp can be sprayed 2000 to 3000 times every 15 to 20 days for three time, It can be used for coloring quickly, dyeing uniformity, beautifying fruit to increase fruit sweetness, improving quality, improving hardness, prolonging preservation, and preventing fruit from falling before picking, early listing and high selling price.
Diethyl aminoethyl hexanoate 8% sp coloring scheme：Quick coloring and uniform color. Contrastive scheme：Slow coloring and uneven color