Table 2. Rice varieties planted by farmers in Central Luzon, Philippines, 1966–2012.
| Characteristic | 1966–67 | 1974–75 | 1986–87 | 1998–99 | 2003–04 | 2007–08 | 2011–12 |
|---|---|---|---|---|---|---|---|
| Number of unique varieties planted | |||||||
| All year | 32 | 27 | 47 | 38 | 34 | 46 | 45 |
| Wet season | 31 | 22 | 37 | 27 | 27 | 35 | 37 |
| Dry season | 7 | 11 | 21 | 25 | 20 | 28 | 18 |
| Top 75% | 10 | 7 | 7 | 8 | 7 | 9 | 9 |
| Most popular variety | Tjeremas | IR 20 | IR 64 | IR 64 | PSB Rc82 | NSIC Rc128 | NSIC Rc216 |
| Intensity (% area) | 20 | 36 | 49 | 30 | 34 | 20 | 19 |
| Incidence (% farmers) | 13 | 30 | 34 | 28 | 28 | 18 | 20 |
| Year of release of MVs adopted | |||||||
| Most popular | TV | 1969 | 1985 | 1985 | 2000 | 2004 | 2009 |
| Newest | All TVs | 1978 | 1987 | 1998 | 2003 | 2007 | 2010 |
| Oldest | All TVs | 1969 | 1969 | 1985 | 1985 | 1994 | 2000 |
| Weighted average age of MVs planted | _ | 4.3 (WS) | 4.6 (WS) | 8.8 (WS) | 5.2 (WS) | 6.4 (WS) | 2.8 (WS) |
| _ | 2.6 (DS) | 3.4 (DS) | 9.0 (DS) | 7.5 (DS) | 3.8 (DS) | 4.7 (DS) | |
| Number of respondents | 95 | 59 | 120 | 85 | 116 | 107 | 95 |
| Area surveyed (ha) | 165 (WS) | 149 (WS) | 206 (WS) | 127 (WS) | 202 (WS) | 118 (WS) | 145 (WS) |
| 25 (DS) | 29 (DS) | 111 (DS) | 71 (DS) | 129 (DS) | 85 (DS) | 119 (DS) |