Effect of Crop Load on Yield and Quality Parameters in Apple cv. Gala Redlum

Abstract

The present study was conducted at the experimental field of the Division of Fruit Science, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir during the year 2021-2022. The primary objective of this study was to assess the impact of varying crop loads on the growth, yield, quality, and return bloom of Gala Redlum apples, with specific emphasis on trunk cross-sectional area (TCSA). The experimental design involved a Randomized Complete Block Design (RCBD) with three replications, utilizing 4-year-old Gala Redlum plants. The trees were subjected to manual thinning, resulting in crop loads of 4, 6, 8, 10 fruits per cm² of TCSA, with a non-thinned control group. Notably, the maximum fruit yield (18.52 kg/tree) was observed in the control group (no thinning), while the minimum yield (7.57 kg/tree) was recorded in the C2 group (4 fruits per cm² of TCSA), followed by C3 (11.03 kg/tree). Furthermore, the impact of different TCSA ranges on fruit yield was statistically significant. The maximum fruit yield (14.45 kg/tree) was observed in the S2 group (10-12 cm² TCSA), while the minimum yield (12.16 kg/tree) was noted in the S1 group (8-10 cm² TCSA). Yield efficiency, measured as yield per unit of TCSA, reached its highest (1.838 kg/cm²) in the control group and is lowest (0.766 kg/cm²) in the C2 group (4 fruits per cm² of TCSA). The results further revealed that the C2 group (4 fruits per cm² of TCSA) exhibited the maximum Total Soluble Solids (TSS) content (14.73 °Brix), total sugars (11.62%), and TSS: Acid ratio (61.45). Similarly, the C3 group (6 fruits per cm² of TCSA) demonstrated elevated TSS (14.20 °Brix), total sugars (10.99%), and TSS: Acid ratio (54.66). Additionally, the S2 group (10-12 cm² TCSA) recorded the highest TSS (13.75 °Brix), total sugars (10.51%), and TSS: Acid ratio (50.53). The combination of C2S2 and C3S2 treatments exhibited superior results, with the highest TSS (14.82 °Brix), total sugars (11.77%), and TSS: Acid ratio (62.64). Fruit firmness (8.81 kg/cm²) and fruit acidity (0.327%) were maximized in the C1S1 treatment combination.