Altitudinal variation in the morphological and biochemical traits of Khasi Mandarin (Citrus reticulata Blanco) in East Kameng District, Arunachal Pradesh

The study aimed at to assess the morphological and biochemical variations of Khasi Mandarin in three blocks of East Kameng district—Seppa, Bana, and Bameng—focusing on the impact of altitude. Seppa, located at a lower altitude (<800 msl), exhibited the largest fruit diameter (4.62 cm) and the highest total soluble solids (TSS) content (10.01° Brix), along with the longest and widest leaves. In contrast, Bameng, situated at a higher altitude (>1300 msl), had smaller fruits with lower weight (27.22 g) and volume (42 cc), but showed higher titratable acidity (1.06%) and ascorbic acid content (30.72 mg 100 g–1) indicating improved nutritional quality at higher elevations. Bana, at a mid altitude, produced fruits with the highest weight (54.83 g) and volume (47.62 cc), offering a balanced profile of size and quality. Seed traits, including count and size, varied moderately among the locations, further emphasizing the role of altitude in shaping the fruit’s characteristics. This study highlights the importance of altitude in determining the morphological and biochemical traits of Khasi Mandarin, providing valuable insights into how climate and geographical factors influence fruit quality in different regions of Arunachal Pradesh.