Table 2 Yield losses resulting from zero-pesticide application (change from TFI 4.1 to TFI 0) estimated with two response functions (log and quadratic) and two statistical methods (quantile regression and stochastic frontier). Yield losses are expressed in t ha−1 and in percentages of the yields obtained with the current level of pesticide use. Results obtained with the quantile regression method are shown for three quantiles (median and percentiles 20 and 80%). 95% confidence intervals are given in brackets
Function | Statistical method | Yield loss (t ha−1) | Yield loss (%) |
|---|---|---|---|
Log | Quantile regression (median) | 2.31 (1.36, 2.74) | 32.26 (19.64, 37.71) |
Log | Quantile regression (percentile 20%) | 2.02 (1.4, 2.92) | 33.04 (23.56, 49.98) |
Log | Quantile regression (percentile 80%) | 2.13 (1.56, 2.69) | 25.97 (19.65, 32.7) |
Log | Stochastic frontier | 2.33 (1.74, 2.93) | 26.43 (19.77, 33.3) |
Quadratic | Quantile regression (median) | 2.23 (1.27, 2.78) | 30.79 (18.36, 36.94) |
Quadratic | Quantile regression (percentile 20%) | 1.84 (1.07, 2.74) | 30.04 (18.5, 42.73) |
Quadratic | Quantile regression (percentile 80%) | 2.1 (1.27, 2.56) | 25.5 (15.63, 30.47) |
Quadratic | Stochastic frontier | 1.98 (1.48, 2.51) | 24.31 (18.49, 31.5) |
