Standardization of Fertigation Rate and Scheduling in Tomato (Solanum lycopersicum L.) under Open Conditions

Background: Optimising fertigation rate and nutrient scheduling is important for tomato production under open-field conditions. Aim: To optimise the fertigation rate and scheduling of water-soluble fertilisers for tomato under open conditions. Study Design: Factorial RCBD. Place and Duration of Study: RHREC, UHS Campus, GKVK, Bengaluru, Karnataka, during rabi 2025–26. Methodology: The experiment comprised ten treatments and three replications: nine combinations of three fertiliser levels (125, 100, and 75% RDF) and three fertigation schedules, and conventional soil application of RDF as the control. Growth parameters, including plant height, number of branches, and flowering time, as well as yield parameters, including fruit number and yield, were recorded. Results: Among the fertiliser levels, 100 % RDF recorded the significantly highest fruit yield (77.91 t ha⁻¹), whereas 75 % RDF resulted in the highest number of fruits per plant (66.17). Among the fertigation schedules, S₃ recorded superior performance for all yield attributes and produced the significantly highest yield (88.39 t ha⁻¹). Among the treatment combinations, T₉ (75% RDF + S₃) recorded the significantly highest fruit yield (90.83 t ha⁻¹) whereas T₆ (100% RDF + S₃) recorded the maximum average fruit weight (91.83 g). Conclusion: The 75% and 100% RDF levels produced comparable results for several parameters, while schedule S3 outperformed the other schedules. Thus, 75% RDF applied through S₃ was identified as an effective fertigation strategy under the experimental conditions.