How to improve color on grapes

1,With high phosphorus and high potassium foliar fertilizer as the main component ( monopotassium phosphate).
Advantages: It is safe to use, has no side effects, can be used for many times without affecting the taste and storage and transportation; it can also improve the sugar content of the fruit.
Disadvantages: Coloring is too slow.
Medication time: use as soon as possible, and can be used after bagging.
2,Take anthocyanin precursor substance as the main component.
The main reason for the color change of grapes is the increased anthocyanin content. Advantages: high safety, no side effects, better coloring effect than potassium dihydrogen phosphate, but poor taste.
Disadvantages: The coloring is relatively slow, and the price is high. It is recommended to spray on the fruit surface, and the effect of spraying on the leaves is poor.
Medication time: Use when the grapes begin to color.
3,With abscisic acid as the main ingredient (S-ABA)。
Advantages: faster coloring, does not affect the photosynthesis of the leaves, the fruit does not reduce the sugar content of the fruit, and the grains are not soft.
Disadvantages: only the surface of the fruit spreads, and the dispersion effect is good; the use of drugs is easy to attract the fruit particles; the use of drugs is easy to attract uneven attention, and the use of excessive use will become purple. It can be used at the beginning of dyeing (it will be restored after 10%). It will be restored if it is used too early. The color has changed, but it is still very poor.
4,With ethephon as the main component (Diethyl aminoethyl hexanoate·ethephon).
Advantages: faster coloring (the effect can be seen in 7 days); leaf spray, easy to use; more uniform coloring, low price.
Disadvantages: It is easy to cause aging of the leaves, use too early or too many times, it is easy to cause water jar disease; too much concentration can also cause particle drop.
Period of use: Use only when the grapes begin to color.
5,Based on  Prohexadione calcium and S-ABA as the main component (Prohexadione calcium+S-ABA).
Advantages: safe to use, no grains, no soft fruit, by expanding the fruit to accelerate the formation of dry matter so as to transmit the ripe signal to the fruit, which can increase the sugar content and improve the quality.
Disadvantages: Compared with ethephon, the color conversion speed is slow.

1. Use time.
It must be used when the grapes begin to change color and start to "lay the red line". Premature use will not only reduce the sugar content of the fruit, but also cause premature leaf senescence (ethephon), resulting in "water jars".
2. Use medicament.
Try not to choose single ethephon and abscisic acid products; if you use ethephon alone, the leaves will age quickly, which can easily cause premature aging of the tree.
Recommendation: Formula of "protective agent + coloring agent" Prohexadione calcium + S-ABA +  diethyl aminoethyl hexanoate (DA-6) + ethephon, brassinolide + ethephon.
3. How to use it.
(1) Ethephon: Low-concentration whole-plant spray is better than high-concentration light spray nozzle (top blade).
(2) Prohexadione calcium + S-ABA + diethyl aminoethyl hexanoate: foliar spray, focusing on ear spray. It can be mixed with most insecticidal and sterilizing fertilizers.
4. Precautions for the use of regulators:
(1) Use ethephon with acid foliar fertilizer. (Ethephon will accelerate its release when the pH is greater than 4)
(2) Be sure to water and fertilize after use. Regulators are not nutritious, they are generally used together with fertilization. Prohexadione calcium with potassium fertilizer has a better effect in expanding fruit, sweetening and promoting coloring.
(3) After the first use for 7 days, if the effect is not good, you can use it again, but there must be an interval of 7 days. Too frequent use will cause rapid senescence of leaves.