Table 3. Agronomic and grain quality characteristics of rice varieties planted by farmers in Central Luzon, by survey year (weighted by area), 1974–2012 a .
| Characteristics | 1974–75 | 1986–87 | 1998–99 | 2003–04 | 2007–08 | 2011–12 |
|---|---|---|---|---|---|---|
| Agronomic | ||||||
| Average yield (t/ha) | 4.1 d | 5.1c | 5.1 c | 5.1 c | 5.3b | 5.8a |
| Maturity (DAS) | 126a | 119b | 116c | 115 d | 115 d | 113 e |
| Plant height (cm) | 106a | 103b | 98e | 100d | 98e | 101c |
| Grain quality | ||||||
| Milling recovery (%) | 67.6bc | 69.8a | 67.7bc | 67.9b | 67.3c | 67.9b |
| Head rice (%) | 60.5 a | 60.0a | 52.4b | 46.1c | 44.7d | 45.7c |
| Grain length (cm) | 5.49f | 6.56e | 6.72d | 6.78c | 6.84b | 7.15a |
| Grain shape (ratio) | 2.61d | 3.19c | 3.25ab | 3.23b | 3.26a | 3.25ab |
| Chalky grains (%) | - | - | 3.4d | 4.9c | 7.9b | 13.0a |
| Amylose content (%) | 25.5a | 24.1b | 22.5c | 22.0d | 20.3e | 20.5e |
aValues in a row with the same letter are not significantly different at 5% level of significance.