R2 = bExy / Ey2
 = (0.511)(5.42) / 3.89
 = 0.71


 This equation, and others calculated the same way,
along with the data points, can be displayed graphically
for visual comparisons (Figs. VII-1 and VII-2). In each
case, the R2 value indicates a very good fit. It appears
that the materials respond differently to environment and
that the local material is superior in "poor" maize
environments while the improved material is superior in
"good" maize environments. Both cultivars, however,
respond favorably to fertilizer in both good and poor
environments.
 The analysis provides evidence that the farms are part
of two recommendation domains. This evidence warrants
further study. In the poorer environments (e < 2), i.e.,


0
4-


.- 3
.-


E
"2


W I-
5:


YL= 0.34 +0.51e
 R2=.71


Y= -0.87+ 1.03e
 R2=.78


* *


ENVIRONMENTAL INDEX (e), metric tons
ENVIRONMENTAL INDEX (e), metric tons


Grain yield response for local maize (L)
and CCA composite (C) to environment, without
fertilizer, Phalombe Project, Malawi.


FIG.VII-1.