Table 8.
Coefficients of determination (R2) of regressions between integrated chlorophyll content index (CCIi) values and the integrated nitrogen nutrition index (NNIi) for each phenological stage in a sweet pepper (Capsicum annuum) in 2017. The crop was subjected to five different N treatments with four repetitions. According to the Akaike information criterion, the best-fit regression model (exponential, linear, power, quadratic, and natural logarithm) is shown. Also, it is presented the fitted equation and standard error of the estimate (SEE). All regressions were highly significant, with p-value < 0.001. N is the number of data points of regression.
| Phenological Stage | Model | Equation | R 2 | SEE (±NNIi) | N |
|---|---|---|---|---|---|
| Vegetative | Natural Logarithm | NNIi = 0.537∙log(CCIi) − 1.0186 | 0.87 | 0.06 | 20 |
| Flowering | Quadratic | NNIi = −0.001∙CCIi2 + 0.0683∙CCIi − 0.9521 | 0.94 | 0.05 | 20 |
| Early fruit growth | Linear | NNIi = 0.014∙CCIi + 0.1119 | 0.96 | 0.05 | 20 |
| Harvest | Natural Logarithm | NNIi = 0.487∙log(CCIi) − 1.0157 | 0.87 | 0.08 | 20 |