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are meeting their basic food needs with the production of their best
fields assign a lower priority to harvesting marginal ones if they per-
ceive a more profitable activity to which they may dedicate their
labor. Thus, their lower productivity of marginal lands is accentuated
by losses of harvest to nematodes and frost.
In the lakeside ecological zone, it is not unreasonable to assume
a mean yield of 6000 kilograms per hectare for Solanum tuberosum. Thus,
our hypothetical household could expect to harvest 1500 kilograms of
Solanum tuberosum. Solanum andigenum is planted only on more marginal
lands subject to extreme temperatures, so it may be assumed that the
district-wide mean of 5229 kilograms per hectare more accurately re-
flects its productivity than does the mean for Solanum tuberosum.
This indicates that our hypothetical household can expect to harvest
about 157 kilograms of Solanum andigenum. The minor tubers are planted
exclusively in the more temperate areas of the lakeside ecological zone.
This allows us to be relatively confident that the district-wide mean
yields for the minor tubers are not unreasonable for calculating the
harvest per hectare in Sarata, so that our household can expect about
868 kilograms to be harvested. Mean yields of 3769 kilograms per
hectare for ulluku (Ullucus tuberosus) and 4118 kilograms per hectare
of isahu (Tropaeolum tuberosum) permit us to estimate harvests of 38
and 41 kilograms, respectively, of these tubers by our hypothetical
household. We may thus estimate a total tuber harvest of 2604 kilograms
for the household being described. This information is summarized in
Table 5-8.