Optimizing Irrigation Water and N Levels for Higher Yield and Reduced Blossom End Rot Incidence on Tomato

Abstract

This study was conducted during 2018/19 under drip irrigation in the dry season to examine the effect of irrigation and N levels on yield, economic performance, and incidence of blossom end rot (BER) on tomato. A 3 × 4 factorial design with subdivided plots was implemented. Three irrigation levels (50%, 75%, and 100% ETc) were randomly assigned in the main plots and four N levels (0, 46, 92, and 138 kg ha−1) to the subplots. Climate data were imported into AquaCrop model climate dataset for determining irrigation water amount and irrigation scheduling. Irrigation scheduling was determined using the FAO AquaCrop model. Data were subjected to analysis of variance (ANOVA) using GenStat software. There was significant interaction effect of irrigation and N levels on yield, yield parameters, and BER incidence on tomato. Highest fruit diameter and fruit length were attained from the combined application of 75% ETc and 138 kg N ha−1. Besides, maximum fruits per plant and marketable yield were obtained under combined use of 100% ETc with 138 kg N ha−1 and 75% ETc with 92 kg N ha−1, respectively, whereas lowest yield performance was recorded when 50% ETc is coupled with 0 kg N ha−1. However, highest (21.91%) and lowest (7.03%) BER incidence was found under the combined use of 50% ETc and 0 kg N ha−1 100% ETc and 92 kg N ha−1, respectively. The economic analysis revealed that application of 46 kg N ha−1 was economically feasible irrespective of the irrigation water levels.