Potassium Fertilization Improves Growth, Yield, and Quality of Kinnow Mandarin under North Western Zone of India

Abstract

Potassium is known for enhancing crop productivity, due to its active involvement in maintaining cation-anion balance, osmoregulation, photosynthesis, cytoplasmic pH regulation, proteins and starch synthesis, enzyme activation in plant system. Despite the recognized importance of potassium in citrus production, region-specific dose optimization for Kinnow mandarin in Punjab’s semi-arid soils remains largely unexplored, remained the main reason for poor fruit quality and yield due to adoption of sub-optimal levels of potassium application in kinnow. The present study was conducted to optimize potassium fertilizer dose in Kinnow mandarin for better fruit quality and production in Semi-arid zone of Punjab, India. The experiment was conducted during the year 2022 to 2024 using randomized block design with three replications, consisted of seven treatments of K2O fertilizer (0.0, 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 kg/plant) applied in the month of December-January besides the recommended doses of fertilizers. The pooled data of 3 years revealed that fruit weight, size, juice content, soluble solids content, carotenoids and sugars content were improved substantially with K fertilizer than the control. Fruit weight, length and diameter increased by 13.4, 21.6 and 24.1%, respectively in the plants applied with 0.6 kg K2O plant-1 over the control, whereas higher dose of K2O application enhanced granulation that resulted in lower recovery of juice content. The plants applied with lower K levels produced fruits of smaller size, thin peel and poor consumers’ acceptability. Correlation studies indicated that fruit size, weight and peel thickness were directly related with leaf and soil K content. These findings provide the region-specific recommendation for optimal potassium fertilization in Kinnow mandarin, supporting improved fruit yield, quality, and farmer profitability in Punjab’s semi-arid region.