An efficient irrigation based on hargreaves potential evapotranspiration to improve yield for tomato plantation

Abstract

With a tropical climate in Malaysia, varieties of vegetables can grow all year round. Nevertheless, during the hot season, watering the plant is challenging, especially for vegetables that are intolerant to heat such as tomato plants. Over-watering or under-watering  could decrease the yield and quality of tomatoes. Therefore, in this study, we proposed an efficient irrigation system based on Hargreaves’s potential evapotranspiration to improve the yield and quality of tomato plants in Melaka, Malaysia. Using the  Hargreaves equation, the correlation between the surrounding temperature and the amount of water needed by the tomato plants is investigated. Three growth stages are considered: early stage (0 − 30 days of planting), middle stage ( 31 − 76 days of planting), and final stage (77 − 105 days of planting). Based on a 30-day analysis, on average, tomato plants require 45.5 mL/day, 87.4 mL/day, and 60.8 mL/day respectively for the early, middle, and final stages of growth. A mobile monitoring application is also developed using MIT App Inventor for users to monitor the temperature, humidity, soil moisture, pH level, status of water pumps, and the amount of water released to the plants. The proposed system can increase the efficiency of the irrigation process and ultimately, reduce the farming cost.