no fertilizer with fertilizer


Y= average yield


YIELD (Y), metric tons/ha


FIG.VII-3.


Distribution of confidence intervals for
grain yield of local and CCA composite maize,
Phalombe Project, Malawi. High environments-
five farms where average yield (Y) greater
than 2 t/ha.


 To be effective for extension purposes, a way to
differentiate between recommendation domains must be
available. In this case, a study of field histories
showed that the better environments were related to the
use of manure. Manure, in turn, was available only to the
farmers who had cattle. Hence, the better environments,
which comprise one recommendation domain, included those
farmers who had cattle and who used the manure on a field
where maize would be planted.
 Another example of the analysis of farmer-managed
trials comes from ICTA, in Guatemala. In 1976, following
a Sondeo which characterized the western Chimaltenango
area and defined three recommendation domains (Duarte et


-2-
YL YC


 4-
YLF YCF