Agrometeorological MODEL for Estimation of LEAF Area INDEX in Irrigated Processing Tomato.

The leaf area index (LAI) is important information used in crop modellings. The objective of this research was to adjust a mathematical model that best describes the LAI of irrigated processing tomato, using a non-destructive method that uses photographs taken in situ and a public domain software (ImageJ). Samples were taken at 15, 30, 45, 60, 75, 105, 130 days after planting. For the photographic method a ruler of 1m² was placed on the soil in 24 randomized sampling points, and for each point a photograph was taken. A Gaussian model was calibrated for LAI estimation in function of thermal sum from planting date. The model (Y=Y₀+A·e-((X-X₀)²)/2w²) was accurated (MAPE=0,4%) and precise (R²=0.94).