Table 1.
The mean (± SE) seasonal percentage of maize plants damaged by stemborer larvae at 10 weeks after crop emergence in plots of maize planted in sole stands (monocrop) or in push–pull
| District | Cropping system | Mean (± SE) % plants damaged by stemborer larvae | |||||
|---|---|---|---|---|---|---|---|
| Long rains 2013 | Short rains 2013 | ||||||
| t‐value | p‐value | t‐value | p‐value | ||||
| Kuria | Push–pull | 3.7 (1.3) | 15.0 | <0.0001 | 7.5 (1.6) | 4.9 | <0.0001 |
| Monocrop | 29.5 (1.0) | 16.7 (1.0) | |||||
| Migori | Push–pull | 10.0 (1.8) | 5.02 | <0.0001 | 11.7 (1.5) | 3.62 | 0.0015 |
| Monocrop | 26.2 (2.6) | 24.3 (3.1) | |||||
| Rongo | Push–pull | 8.0 (1.4) | 4.36 | 0.0003 | 9.7 (1.5) | 4.07 | 0.0005 |
| Monocrop | 22.2 (2.9) | 21.0 (2.3) | |||||
| Rachuonyo | Push–pull | 6.3 (0.9) | 6.49 | <0.0001 | 9.5 (1.3) | 3.79 | 0.0010 |
| Monocrop | 20.8 (2.0) | 22.7 (3.2) | |||||
| Kisii | Push–pull | 9.1 (1.2) | 4.64 | 0.0001 | 8.6 (1.3) | 5.13 | <0.0001 |
| Monocrop | 22.3 (2.6) | 25.1 (2.9) | |||||
| Bungoma | Push–pull | 14.8 (1.1) | 3.15 | 0.0046 | 11.7 (1.6) | 3.12 | 0.0050 |
| Monocrop | 23.8 (2.6) | 21.8 (2.8) | |||||
| Teso | Push–pull | 10.9 (1.6) | 3.53 | 0.0019 | 9.2 (1.4) | 4.78 | <0.0001 |
| Monocrop | 21.2 (2.4) | 20.4 (1.9) | |||||
| Bondo | Push–pull | 7.3 (1.2) | 1.97 | 0.0614 | 7.5 (1.4) | 4.14 | 0.0004 |
| Monocrop | 11.1 (1.5) | 21.9 (3.1) | |||||
| Vihiga | Push–pull | 7.6 (1.5) | 4.95 | <0.0001 | 9.4 (1.5) | 4.61 | 0.0001 |
| Monocrop | 22.5 (2.6) | 23.5 (2.6) | |||||
| Busia | Push–pull | 7.6 (1.8) | 3.52 | 0.0019 | 8.5 (1.7) | 4.17 | 0.0004 |
| Monocrop | 19.1 (2.7) | 22.7 (2.9) | |||||
| Siaya | Push–pull | 10.3 (1.9) | 4.13 | 0.0004 | 10.7 (1.2) | 5.35 | <0.0001 |
| Monocrop | 22.4 (2.2) | 24.6 (2.2) | |||||
| Kisumu | Push–pull | 8.9 (1.1) | 5.81 | <0.0001 | 8.2 (1.3) | 3.55 | 0.0018 |
| Monocrop | 26.5 (2.8) | 19.5 (2.9) | |||||
Means represent data averages from 100 maize plants per plot, and from 12 farmers per district. Each farmer planted a push–pull and a maize monocrop plot. Maize (either ‘Nyamula’ or ‘Jowi’) was planted as described in Khan et al. (2008b). At 10 weeks after emergence of maize, 100 plants were inspected in each plot for any characteristic foliar damage caused by stemborer larval feeding, and data expressed as percentage of maize plants damaged by stemborers per plot.