Table 4. Analysis of variance (ANOVA) on the yield and economic return of common bean plants sprayed weekly with extracts of four plant species and positive/negative control treatments.
Values in the same column followed by the same letter are not significantly different from each other at the 95% confidence interval using Tukey’s post-hoc Honestly Significant Difference (HSD) test.
| Treatment | Pods per plant | Seeds per pod | 100 grain weight (g) | Overall yield (kg/ha) | Marginal net return (USD/ha) | Marginal rate of return (USD/ha) | Percent increase over control |
|---|---|---|---|---|---|---|---|
| Control - | 3.49 d | 2.31 c | 55.63 c | 1201.92 c | 1136.66 c | 4.06 c | - |
| Control + | 6.12 b | 3.54 a | 60.19 b | 1578.48 b | 1483.65 b | 4.06 c | 30.5 |
| Lippia javanica | 5.69 b,c | 3.56 a | 60.45 b | 1424.25 b,c | 1408.30 b,c | 4.42 b,c | 23.8 |
| Tephrosia vogelii | 7.15 a | 3.74 a | 60.41 b | 1921.75 a | 2011.34 a | 5.62 a | 76.8 |
| Tithonia diversifolia | 7.44 a | 3.66 a | 60.56 b | 1835.50 a | 1906.79 a | 5.32 a,b | 67.6 |
| Vernonia amygdalina | 4.81 c | 3.06 b | 65.39 a | 1685.71 a,b | 1725.22 a,b | 5.50 a | 51.7 |
| F | 41.92 | 21.21 | 10.14 | 18.67 | 19.16 | 11.82 | |
| Pr > F | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 |