Table 1.

Parameters of the multiple regression model to predict the leaf area index (LAI). The model was constructed with 180 plots (60 per flight date) to calculate multiple regression prediction equations by including the VARI (Visible Atmospherically Resistant Index) vegetation index, PH (plant height), and f_c (fraction of canopy cover) from remote sensing. Equation parameters are shown. The model was validated by calculating LAI using the equation obtained from multiple regression in 18 wheat trials with prediction accuracies (Pred Ac) shown as Pearson coefficients P(r) between observed LAI and predicted LAI.

Model	Estimation of Coefficients	Standard Error	Prob > |t|
INTERCEPT	−1.071	0.188	<0.0001 *
PH	5.063	0.274	<0.0001 *
VARI	5.451	0.766	<0.0001 *
fc	−1.661	0.440	0.0002 *
Summary of fit
RMSE	0.505
R2	0.829
Pred Ac RF (Pearson r)	0.504

* indicates statistically significant differences assuming a test significative level of 0.05.