Table 3.
Least squares means (% of total damage on plants) and risk ratio for Agriotes ustulatus, Agriotes sordidus and Agriotes brevis in different soils and different pH levels, percentage of organic matter and number of larvae/trap calculated with a generalized linear model
| Variable | Number of fields | Least squares means % Damage (SE) | RR (95 % CI) | Chi-square | P |
|---|---|---|---|---|---|
| Agriotes ustulatus | |||||
| Soil | 25.96 | <0.001 | |||
| Clay | 7 | 0.27 (0.12) | 0.22 (0.19–0.25) | 12.86 | <0.001 |
| Loama | 31 | 1.24(0.23) | |||
| Clay loam | 3 | 0.08 (0.13) | 0.06 (0.002–1.78) | 2.62 | 0.105 |
| pH | – | – | – | ||
| Organic matter (%) | 2.04 (1.23–3.39) | 7.53 | <0.001 | ||
| No. larvae/trap | 1.25 (1.21–1.28) | 455.42 | <0.001 | ||
| Agriotes sordidus | |||||
| Soil | 67.50 | <0.001 | |||
| Silty clay loam | 2 | 1.37 (1.08) | 0.35 (0.07–1.67) | 1.74 | 0.187 |
| Loam | 9 | 1.30 (0.44) | 0.33 (0.16–0.67) | 9.29 | 0.002 |
| Clay loam | 15 | 0.63 (0.19) | 0.16 (0.09–0.29) | 36.05 | <0.001 |
| Silty clay loam | 12 | 2.18 (0.63) | 0.55 (28–1.06) | 3.16 | 0.076 |
| Sandy loam | 9 | 2.29 (0.52) | 0.58 (0.36–0.93) | 5.07 | 0.024 |
| Loamy sanda | 32 | 3.96 (0.46) | |||
| pH | 0.24 (0.03–2.22) | 1.50 | 0.221 | ||
| Organic matter (%) | 0.59 (0.25–1.37) | 1.74 | 0.188 | ||
| No. larvae/trap | 1.96 (1.74–2.21) | 106.19 | <0.001 | ||
| Agriotes brevis | |||||
| Soil | |||||
| Clay | 11 | 11.73 (1.19) | 0.55 (0.32–0.94) | 4.78 | 0.029 |
| Loam | 4 | 2.84 (1.13) | 0.13 (0.04–0.40) | 12.69 | <0.001 |
| Clay loam | 8 | 8.45 (1.26) | 0.40 (0.23–0.67) | 11.96 | <0.001 |
| Loamy sanda | 2 | 21.36 (5.58) | |||
| pH | 15.40 (0.29–>20) | 1.82 | 0.178 | ||
| Organic matter (%) | 1.27 (0.56–2.88) | 0.32 | 0.569 | ||
| No. larvae/trap | 1.07 (1.06–1.09) | 128.49 | <0.001 | ||
RR risk ratio, SE standard error, CI confidence interval
aRepresents the reference level of comparison in the calculation of risk ratio