The Effect of Fertilizer Application on the Sweetness Levels of Vitis vinifera (Jupiter Variety)

Abstract

This study aims to examine the influence of different fertilizer types on the sweetness levels of the Jupiter grape variety (Vitis vinifera) by measuring the fruit's Brix levels. The research was conducted in a greenhouse shelter at Politeknik Nilai, Negeri Sembilan. The study was carried out on Jupiter variety grapevines that had reached fruiting maturity. The experiment compared three types of fertilizers: Chemical NPK Blue 12:12:17, AB Solution fertilizer, and organic fertilizer. These fertilizers were applied from the initial stage prior to pruning, through bud break and fruit formation, up to the harvesting stage according to tree plots. The Brix sweetness levels were measured using a refractometer starting from fruit maturity (70 days after pruning) until harvest (100 days after pruning). The results showed that all fertilizer treatments significantly increased Brix levels. The AB Solution liquid fertilizer produced the highest Brix levels, followed closely by Chemical NPK Blue 12:12:17 and organic fertilizer. The study concludes that the use of AB Solution liquid fertilizer can enhance the sweetness of Jupiter Vitis vinifera grapes compared to NPK chemical and organic fertilizers. Additionally, the quality of the fruit yield can also be improved through the implementation of this AB solution fertilizer.