Horticultural Science and Technology 원예과학기술지 ISSN:1226-8763(Print) 2465-8588(Online)

The aim of this study is to ascertain suitable harvesting time and yields for the development of color chart for the establishment of harvesting standard based on the skin color of ‘Shine Muscat’ grapes. The experiment was conducted at an orchard in Cheonan, Chungcheongnam-do, Korea and clusters per vine were set to harvest 1,800 kg, 2,100 kg and 2,400 kg per 10 a. Even though the yield was increased up to 2,400 kg per 10 a, there was no difference in the size of the fruit. However, with regard to fruit quality, grapes controlled to 2,400 kg per 10 a had lower soluble solids content, poorer coloring, higher acidity and hardness compared to other grapes controlled to 1,800 kg and 2,100 kg. Also, the chlorophyll content of grapes controlled to 2,400 kg per 10 a was higher compared to other grapes. Accordingly, for ‘Shine Muscat’ grape cultivation, it is considered that controlling the yield to less than 2,100 kg per 10a is effective in terms of fruit quality. Soluble solids content in grapes controlled to 1,800 kg and 2,100 kg per 10 a, exhibited a continuous increase with progress in ripening. The acidity and soluble solid-acid ratio remained unchanged for about 110 days after full bloom. Also, the color stage reached the peak at 120 days after full bloom. Therefore, it is considered that controlling the yield of ‘Shine Muscat’ grapes to within 2,100 kg per 10 a and harvesting 120 days after full are effective in meeting both productivity and fruit quality. To develop a color chart for the matured determination of ‘Shine Muscat’ grapes, the growing period was divided into 5 stages and based on these stages; fruit quality and pigment content were compared. A color chart was made by determining the appropriate range of soluble solids content and acidity.