Table 2. F-values for the ANCOVA performed on the 7-year average of the NDVI integral (NDVI-I), the date of maximum NDVI (DMAX), and the average NDVI for three periods of the year (Q_1: Julian dates 1-153, late winter-spring; Q_2: Julian dates 154-237, summer; Q_3: Julian dates 238-365, fall-early winter). Land use classes were: irrigated crops, non-irrigated crops, native grasslands, and Conservation Reserve Program areas. The covariates included in the model were mean annual precipitation (MAP), mean annual temperature (MAT) and percentage of clay content of the soil (CLY).
** p < 0.01
* p < 0.05