TOMATO GROWTH (LYCOPERSICON ESCULENTUM MILL), AND NUTRIENT UTILIZATION IN RESPONSE TO VARYING FERTIGATION PROGRAMS
A field study was conducted with two fertigation treatments, and one conventionally irrigated and fertilized treatment. The aims of our experiment were: i) to study the effect of combined NO3-NH4-K nutrition on NPK uptake and the production and quality of tomatoes, ii) to establish the most convenient proportion of NPK at different phenological stages, and iii) to evaluate the predominant form of soluble N in the plant tissue at the same stages. Dry matter accumulation was always higher in fertigated plants than in those conventionally irrigated and fertilized. Total NPK uptake in plants differed under drip irrigation and conventional irrigation treatments, nevertheless, crop requirements were consistently K>N>P. The NPK ratio in the fertigation solution was established for different growing stages. Fruit production and quality parameters (size, firmness and soluble sugars) were consistently enhanced by fertigation. The mean values for transported reduced-N in petiole sap increased from 18 % during the early vegetative stage to 32 % of total soluble-N during fruit ripening, and the fraction of NO3-N dropped inversely. More than 70 % of total soluble-N in tomato plants is transported as NO3-N.
Alcántar, G.G., Villarreal, M.R. and Aguilar, A.S. (1999). TOMATO GROWTH (LYCOPERSICON ESCULENTUM MILL), AND NUTRIENT UTILIZATION IN RESPONSE TO VARYING FERTIGATION PROGRAMS. Acta Hortic. 481, 385-392
NPK ratio, drip irrigation, Mexico