Modeling of Tomato Seedling Growth in Greenhouse

Abstract

This study was undertaken to model the growth of tomato seedlings under greenhouse conditions. The micro-environment of the seedlings (temperature and solar radiation) was correlated with the seedling growth factors. Seed emergence was studied for five different temperatures, and a mathematical model was developed to fit the data to determine relationship between seed germination and soilless medium temperature. In post-emergence phase, a model was developed to estimate the dry weight attained by the seedlings as a function of cumulative heat units (CHU) and cumulative solar radiation (CSR). It was observed that the number of days required for seedling emergence was a function of average root medium temperature. Tomato seedlings emerged in 12 days at average root medium temperature of 20 and 35 °C, while the minimum duration was observed to be 7 days at 30 °C. The power model represented the seedling emergence behavior with correlation coefficient of 0.96. The growth of tomato seedlings after emergence was affected by both CHU and CSR. Modified Gompertz model explained the post emergence tomato seedling growth under different climatic variations with correlation coefficient from 0.96 to 0.97.