Once established, cassava can grow
in areas that receive just 400 mm of
average annual rainfall. But higher
yields have been obtained with
much higher levels of water supply.
Research in Thailand indicates that
maximum root yields are correlated
with rainfall totalling about 1 700 mm
during the fourth to eleventh month
after planting. Cassava also responds
well to irrigation. In trials in Nigeria,
root yields increased sixfold when
the quantity of water supplied
by supplementary drip irrigation
matched that of the season’s rainfall.