Improve Grape Colour
Dora Agri provides efficient and reliable grape colour improvement solution for growers.
Color is an important indicator for evaluating the quality of grapes, and it is also the main selling point of commercial grapes. It has always been highly valued by grape producers, operators, and consumers. The main pigment that determines fruit color is anthocyanin, and carotenoids and chlorophyll also play an auxiliary role in grape coloring. Anthocyanins mainly exist in the epidermis of grape fruit, and the type and content of anthocyanin are the determinants of the coloring effect of grapes.
The peel color is one of the important sensory indicators of grapes, but in actual production, various factors may cause poor coloration of grapes. In some production areas, due to unsuitable meteorological factors such as light, temperature, and humidity, the grapes have poor coloration, which affects the appearance quality and commercial value of the fruit.
Regarding how to increase the anthocyanin content in grape peels and improve fruit coloring, in addition to traditional methods (adjustment of cultivation techniques, tree nutrient improvement and harvesting time adjustment, etc.), the use of plant growth regulators is also an effective method to improve grape fruit coloring. They have been widely used in the grape industry, which can promote the accumulation of sugar in fruits, regulate the levels of endogenous hormones, and the expression of anthocyanin synthesis-related regulatory factors and structural genes, thereby affecting the coloring and ripening of grapefruits.
Ways to Improve the Colour of Table Grapes
We will review the effects of four plant growth regulators (S-abscisic acid, Ethephon, Propyl Dihydrojasmonate, and Brassinolide) on grape coloration. The mechanism of the main plant growth regulators affecting the coloration of grape fruit was expounded, and the theoretical basis for the application of exogenous growth regulators in promoting/inhibiting grape coloration was provided.
S-ABA (Abscisic Acid)
S-ABA promotes coloration by affecting pigment content. The appearance of peel color is the result of the comprehensive action of chlorophyll, carotenoids, anthocyanins and other pigments. ABA accelerates the degradation of chlorophyll and the formation of anthocyanins in fruit.
S-ABA promotes fruit coloring by affecting the expression of anthocyanin synthesis-related genes. ABA treatment can promote the expression of structural genes and transcription factors of anthocyanin synthesis in grape peel, thereby promoting grape fruit coloring.
S-ABA promotes the coloration of grape fruit by regulating the balance between endogenous hormone content and other hormones, mainly by increasing the content of endogenous ABA and reducing the content of indole acetic acid (IAA), GA and zeatin riboside.
Exogenous ABA can increase the transcription level of ethylene synthesis genes in fruits, thereby increasing the amount of ethylene released from fruits. Ethylene can provide substrates for reactions or directly regulate physiological and biochemical processes by affecting cell membrane permeability, increasing sugar transport and accumulation, thereby promoting flower color. Synthesis of glycosides, thereby promoting fruit coloring.
Ethephon
Ethylene can accelerate physiological processes such as fruit ripening and senescence and shedding, and is called “ripening hormone”. Under certain conditions, ethephon can not only release ethylene, but also induce plants to produce ethylene.
During fruit ripening, ethephon activates phosphatase and other enzymes related to fruit ripening, which can accelerate fruit ripening and shedding. Treating grapes with ethephon can promote the degradation of chlorophyll and the synthesis of flavonoids such as anthocyanins, and improve fruit coloration.
Ethephon can accelerate the respiration rate of grapes, induce the degradation of chlorophyll, promote the synthesis of carotenoids and anthocyanins, promote the color change of the peel, and accelerate the ripening process. Exogenous ethylene can increase the endogenous ethylene content of fruit and the content of anthocyanins, delphinidin, methyl anthocyanin, methyl delphinidin, and delphinidin, and accelerate the color change of fruits.
Propyl Dihydrojasmonate (PDJ)
PDJ is a synthetic jasmonic acid derivative. Compared with MeJA, PDJ has the characteristics of good chemical stability, long duration of physiological effect and easy absorption by plants, and has more practical value. PDJ has been applied to apple and grape production to promote anthocyanin accumulation and improve fruit color. PDJ can promote the accumulation of sugar in fruits, accelerate the degradation of chlorophyll, promote the synthesis and accumulation of anthocyanins, increase the content of anthocyanins in fruits, and promote fruit coloring.
Brassinolide (BR)
There are many applications of brassinolide on grapes. The application effect shows that BR can significantly improve the fruit setting rate of grapes, increase the content of soluble solids, reduce the acid content, promote the coloring and ripening of grapes, and improve the yield and quality of grapes.
Exogenous BR treatment of grape fruit can increase the content of soluble sugar in the fruit, promote the accumulation of anthocyanins, and make the fruit turn color and ripen in advance. BRs can increase endogenous ABA content, promote ethylene release, and reduce IAA content in grapes at the early stage of ripening, thereby promoting grape coloring and ripening.
With the right application, plant growth regulators can have a significant effect on color and can be used in combination with each other or with biostimulants designed to improve color. However, the success of these products depends on a number of factors, and not all growers see the best results.
If you are facing the problem of grape coloring, please contact the Dora Team.
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