Growth indexes for fertigated processing tomatoes in a Mediterranean sub-humid area

Water and nutrient management strongly interact with both the agro-ecosystem and the physiology and morphology of crop plants. To evaluate the effect of water and nutrient inputs on tomato plant growth, the following indexes were calculated: absolute crop growth ratio, relative crop growth ratio and net assimilation ratio. However, other indexes are useful for modelling plant growth, such as partitioning coefficients that show where the dry matter was allocated among the plant's organs, and the amount of dry matter produced per photosynthetic active radiation unit. From the results of a field experiment conducted over three years, growth indexes were calculated to compare the effects of two fertigation scheduling treatments with Not Irrigated-Not Fertilised and Irrigated-Not Fertilised controls. Whole above-ground biomass and fruit biomass were considered separately in this study. A comparison of growth ratio indexes, calculated using modified functional approaches, shows the significant influence of fertigation scheduling on the physiology of the tomato plant, and allows the benefits of fertigation under a simple irrigation regime in a sub-humid area and on fertile soil to be evaluated.