Phenology and nutrient uptake by short-day onion in direct seeding

Abstract

This study aimed to characterize the phenology and nutrient uptake throughout the crop cycle of short-day onion established by direct seeding. The experimental design was in randomized blocks with four replications. The treatments were different evaluation times. The characteristics evaluated were number of leaves, transversal and longitudinal diameter of the bulb, dry mass and plant nutrient accumulation. At the harvest, the plants reached 39.0 g of dry mass. The sequence of nutrient accumulation (g plant^-1) was K (0.80) > N (0.49) > Ca (0.26) > S (0.17) > P (0.09) > (0.05) and (mg plant^-1) Fe (2.17) > Zn (1.42) > Mn (1.36) > Cu (1.06) > B (0.92). For a population of 320,000 plants ha^-1 and yield of 78,9 t ha^-1, the plants extracted at the end of the cycle, 256.2; 157.2; 83.6; 53.2; 29.1; 15.4 kg ha^-1 of K, N, Ca, S, P and Mg, and 694.8; 455.7; 436.0; 339.3; 294.6; g ha^-1of Fe, Zn, Mn, Cu, and B. The bulbs exported 38, 55, 38, 28, 42, 40, 41, 9, 20, 10 and 30% of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn.