Table 1.
Effect of thrips on mean (± SE) French bean pod yield, yield loss, and percentage yield loss as influenced by the various treatments at KALRO-Embu, Kenya in 2011.
| Planting I (March–June 2011) | Planting II (June–September 2011) | |||||||
|---|---|---|---|---|---|---|---|---|
| Treatment | Pod Yield (kg/ha) | Yield Loss due to Thrips Damage [kg/ha (%)] | Damage Score due to Thrips Feeding | Benefit-Cost Ratio | Pod Yield (kg/ha) | Yield Loss due to Thrips Damage [kg/ha (%)] | Damage Score due to Thrips Feeding | Benefit-cost ratio |
| Untreated plot | 2023.8 + 178.0 c | 1416.6 (70) | 4.00 a | - | 2809.5 + 177.7 c | 2017.1 (75) | 4.25 a | |
| Neoseiulus cucumeris | 2500.0 + 218.8 cb | 1250.0 (50) | 2.25 b | 1.38 | 4214.3 + 266.3 b | 1938.5 (46) | 2.75 b | 2.51 |
| Metarhizium anisopliae | 3035.7 + 276.0 cb | 758.9 (25) | 2.25 b | 2.62 | 4297.6 + 272.4 b | 1289.2 (30) | 2.50 cb | 3.47 |
| M. anisopliae + N. cucumeris | 2440.5 + 213.9 cb | 561.3 (23) | 1.75 cb | 1.06 | 4571.4 + 287.7 ab | 1142.8 (25) | 2.25 cbd | 1.93 |
| Imidacloprid | 4785.7 + 418.6 a | 239.2 (5) | 1.25 c | 2.98 | 5785.7 + 364.2 a | 462.8 (8) | 1.25 d | 3.49 |
| Imidacloprid + N. cucumeris | 3690.5 + 324.8 b | 147.6 (4) | 1.25 c | 1.46 | 5595.2 + 352.1 ab | 335.7 (6) | 1.50 d | 2.16 |
| F5,15 | 9.66 | 27.33 | 9.60 | 15.22 | ||||
| P-value | 0.0003 | <0.001 | 0.0003 | <0.001 | ||||
a Means in a column followed by the same letter are not significantly different (Tukey’s HSD test: p < 0.05). b Damage score scales are as follows: 1 = no damage (0%); 2 = slight damage (≤25%); 3 = moderate damage (>25 ≤ 50%); 4 = severe damage (> 50 ≤ 75%) and 5 = very severe damage (>75%). c Benefit-cost ratios greater than one (>1) are profitable.