176 
L 
Fig. 2. The functional relations of 
Eq. [2] for rice. (Adapted from 
Shibayama et al., 1988; and Wiegand, et 
al., 1989). Note: (Kg/ha)/10 = g/m^ 
Fig. 3. The functional relations of 
Eq. [2] for grain sorghum. (Adapted 
from data of Wiegand and Richardson, 
1984). (Not included; no space) 
Fig. 4. Seasonal pattern in the 
vegetation index, PVI, and fractional 
absorbed photosynthetically active 
radiation, FPAF, for three planting 
densities of maize. (After Wiegand et 
al., 1991). 
Table 1. Solution of Eq. [3] term by term for the whole maize growing season 
(emergence to physiological maturity of the grain) by population treatment. 
Population 
Yield 
IAPAR x 
ADM 
x Yield 
I PVI 
I PVI 
IAPAR 
A DM 
(plants/m2) 
(g m-2/PVI unit) 8 
(MJm-2/PVI unit) 
b (g/MJ) c 
(g m-2/g ] 
7.7 
0.576 
0.484 
2.726 
0.436 
5.4 
0.738 
0.520 
3.000 
0.437 
3.1 
0.611 
0.487 
2.774 
0.452 
&/ Yield efficiency, ey, in terms of cumulative 
perpendicular 
vegetation 
W Efficiency of absorption, ea, in terms of perpendicular vegetation index. 
q/ Efficiency of conversion of absorbed PAR to dry matter, ec. 
dJ Harvest index, HI, when dry matter at emergence, DMi, is ignored and DM2 is dry 
matter at harvest.