Nutrient Changes in Berries of "Anab-e-Shahi" and "Perllete" Varieties of Grapes with Advancing Phenology in the Growing Season

Understanding how nutrients accumulate and change throughout the developmental stages according to the BBCH scale can be a very effective technique for developing fertilization programmes for high-quality, marketable grape production. Accordingly, the macro- and micronutrient concentrations at different growth stages were analyzed for two commercial grape cultivars, viz., "Anab-e-Shahi" and "Perlette", by using an extended BBCH scale. The results show nitrogen content was reduced during the sampling period (D1 to D6) from 1.76 percent to 1.09 percent. Potassium concentration in developing berries kept on increasing from 0.15%, at principal growth stage 7 with BBCH code 73 (D1), to 0.26% at principal growth stage 8 code 89 (D6). The lowest phosphorus content of 253.88 ppm and the highest of 338.43 ppm were found in growth stages D1 and D6, respectively. The berry Ca however showed an increase first and thereafter decreased to 225.18 ppm at harvest. Mg content also recorded a similar trend from stages D1 to D6 of the BBCH scale and decreased to 116.08 ppm at D6. B and Cu concentrations increased from D1 to D6, and Mn and Zn increased first and decreased thereafter until harvest. No specific trend was recorded in Fe concentration. The concentration of nutrients in berries at different developmental stages can be used as the standard reference for growing berries using proper fertilization.