Table 5.
Coefficients of variance (%CV) among growth stages (growth cycle, GC) for observed, allometric mass relationships and for optimized model parameters during each of five cropping seasons
| Observed variable or parameter, GCs used | Variable or parameter variation among growth stages (GC), as % of mean fortwo or three different growth stages (CV%) |
|||||
|---|---|---|---|---|---|---|
| 2000 | 2001 | 2003A | 2003B | 2005 | Mean | |
| Observed, allometric mass ratio | ||||||
| Blade/above-ground, GC 8, 18 and 30 | 83·9 | 90·1 | 75·4 | 74·0 | 61·8 | 77·0 |
| Internode/above-ground, GC 18 and 30 | 40·7 | 37·1 | 20·4 | 37·2 | 0·8 | 27·2 |
| Sheath/above-ground, GC 18 and 30 | 50·3 | 52·0 | 54·5 | 56·1 | 35·5 | 49·7 |
| Internode/blade, GC 18 and 30 | 20·2 | 0·83 | 23·0 | 20·6 | 63·6 | 25·7 |
| Sheath/blade, GC 18 and 30 | 34·7 | 33·8 | 19·2 | 25·6 | 34·4 | 29·5 |
| Model parameter | ||||||
| Ps (sheath sink strength), GC 18 and 30 | 19·5 | 8·3 | 21·4 | 7·6 | 10·3 | 13·4 |
| Pe (internode sink strength), GC 18 and 30 | 9·6 | 1·9 | 12·0 | 11·2 | 9·2 | 8·8 |
| Ke (pith sink strength), GC 18 and 30 | 9·9 | 8·3 | 10·7 | 7·6 | 10·3 | 9·4 |
| Bb (blade sink variation), GC 8, 18 and 30 | 7·3 | 7·9 | 4·3 | 9·9 | 15·0 | 8·9 |
| Bs (sheath sink variation), GC and 18 and 30 | 11·7 | 12·3 | 9·0 | 8·0 | 6·8 | 9·6 |
| Be (pith sink variation), GC 18 and 30 | 5·6 | 19·6 | 11·9 | 5·5 | 3·0 | 9·1 |
| r1 (leaf blade resistance), GC 8, 18 and 30 | 9·4 | 9·5 | 8·1 | 8·9 | 11·1 | 9·4 |
| r2 (competition coefficient), GC 8, 18 and 30 | 12·1 | 8·8 | 7·2 | 8·5 | 9·5 | 9·2 |
The growth stages are GC 8 (vegetative), GC 18 (about silking) and GC 30 (about maturity).
For GC 8, variables/parameters involving internodes were not considered because this organ was absent.
Variables/parameters involving cobs and tassels were not considered at all because they were present only at GC 30.