Table 1.
Elongation of roots following 10 days of growth in a very strong soil with a penetrometer resistance greater than 4 MPa or a mechanically weak control (from Materachera et al., 1991)
| Root elongation following 10 days of growth (mm) | |||||
|---|---|---|---|---|---|
| Plant species | Strong soil | Weak control | Percentage reduction by stress | ||
| Monocotyledons | se | se | |||
| Barley | 3.1 | 0.04 | 124.6 | 0.76 | 97.5 |
| Maize | 4.4 | 0.06 | 106.7 | 0.72 | 95.9 |
| Oats | 3.2 | 0.05 | 114.2 | 1.14 | 97.2 |
| Rice | 3.1 | 0.02 | 60.2 | 0.15 | 94.9 |
| Sorghum | 3.4 | 0.02 | 63.8 | 0.15 | 94.7 |
| Rhodesgrass | 2.5 | 0.05 | 60.6 | 0.36 | 95.9 |
| Ryegrass | 3 | 0.02 | 68.2 | 0.28 | 95.6 |
| Wheat | 4.1 | 0.04 | 120.7 | 0.82 | 96.6 |
| Dicotyledons | |||||
| Cotton | 4.5 | 0.02 | 68 | 0.2 | 93.4 |
| Faba bean | 6.8 | 0.03 | 98.7 | 0.74 | 93.1 |
| Lincoln weed | 2.7 | 0.04 | 59.8 | 0.25 | 95.5 |
| Leucaena | 5.2 | 0.05 | 66.9 | 0.22 | 92.2 |
| Lucerne | 4.3 | 0.03 | 75.9 | 0.31 | 94.3 |
| Lupin | 7.1 | 0.06 | 69.4 | 0.27 | 87.8 |
| Medic | 4.5 | 0.03 | 62.4 | 0.22 | 92.8 |
| Oil radish | 4.9 | 0.04 | 88.3 | 0.6 | 94.5 |
| Pea | 7 | 0.04 | 104.6 | 0.85 | 93.3 |
| Pigeonpea | 4.6 | 0.06 | 72.7 | 0.2 | 93.7 |
| Safflower | 5.6 | 0.05 | 94.5 | 0.67 | 94.1 |
| Soybean | 5.7 | 0.06 | 81.5 | 0.41 | 93 |
| Sunflower | 6.4 | 0.05 | 105.3 | 0.68 | 93.9 |
| Vetch | 6.5 | 0.04 | 112.7 | 0.38 | 94.2 |