Quantification of Dry-Matter Accumulation and Nutrient Uptake Pattern of Short Day Onion (Allium cepa L.)

Understanding the physiology of dry-matter accumulation and nutrient uptake pattern of an onion crop is an essential criteria for optimizing fertilizer practices. An experiment was conducted to estimate the dry-matter accumulation and nutrient uptake pattern of short day onion. The dry-matter accumulation and nutrient uptake followed the sigmoid growth curve pattern. Uptake of nitrogen and potassium was slow for the first 15days followed by rapid uptake from 15 to 60days after transplanting and accounted for 76.2-78.2% of total uptake. Takeup of phosphorus, sulfur, manganese, zinc, and copper uptake was greater during 30 to 75days after transplanting and accounted for 64.9-70.6% of total uptake. The deficiency of nutrients during these period reduces the crop yield significantly. The dry-matter accumulation and nutrient-uptake pattern reported in this study provide an opportunity for optimizing quantity and timing of nutrient application through fertilizers for short day onions.