Chemical Characteristics of Exotic Apple Cultivars in Kashmir's Temperate Conditions: Impact of Diverse Pollen Sources

This investigation was conducted in the experimental fields of the Division of Fruit Science at Sher-e-Kashmir University of Agricultural Science & Technology of Kashmir, Shalimar, Srinagar, Jammu & Kashmir, in 2018 to evaluate pollination dynamics in three exotic apple cultivars—Gala Redlum, Fuji Zehn Aztec, and Super Chief Sandidge—grafted on M9-T337 rootstock. Six compatible pollinizers, Gala Redlum, Fuji Zehn Aztec, Super Chief Sandidge, Lal Ambri, Golden Clone-B, and Red Gold, were cross-pollinated, generating 18 cross combinations within a randomized complete block design. Observations revealed synchronized blooming behavior among the varieties, which is crucial for effective pollination. Gala Redlum exhibited early flowering (28th March), whereas Fuji Zehn Aztec flowered late (4th April). Red Gold demonstrated the highest pollen viability (94.99%), with Red Gold and Golden Clone-B displaying superior pollen germination. Cross-compatibility studies identified Red Gold as an effective pollen source, yielding optimal initial fruit set in Gala Redlum and Super Chief Sandidge, whereas self-incompatibility was noted in Super Chief Sandidge and Fuji Zehn Aztec. Fruit set, drop, and retention varied across combinations, with Gala Redlum × Gala Redlum experiencing the maximum fruit drop (62.50%). Red Gold, as a pollen source, yielded the highest fruit weight, length, and seed number in certain combinations. Fuji Zehn Aztec x Red Gold exhibited maximum fruit firmness (8.79 Kg/cm2), while Super Chief Sandidge x Red Gold showed elevated total sugars (12.54%) and reducing sugars (10.48%) with lower acidity (0.15%). Based on synchronization, fruit set, and retention, Red Gold and Golden Clone B were identified as effective pollinators for all exotic maternal cultivars, providing valuable insights for apple orchard management under temperate Kashmir conditions.