Studies have indicated that, when water is avail-
able, cassava maintains a high stomata conductance
and can keep the internal CO2 concentration high,
but when water becomes scarce, it closes stomata
in response to even a small decrease in soil water
potential. The rapid closure of cassava stomata
and the resulting decline in transpiration lessens
the decrease in leaf water potential and soil water
depletion, thus protecting leaf tissues from turgor
loss and desiccation (El-Sharkawy & Cock 1984;
Palta 1984; Cock et al. 1985).
In recent years, there has been a tremendous in-
crease in the research effort to improve the produc-
tion of this important crop (Connor & Palta 1981;
Mohammed et al. 2006). Most of the efforts (Hil-
locks 2002; Aina et al. 2004; Oguntunde 2005)
were focused on enlargement of the in area under
cultivation and the development of high yielding
and drought tolerant varieties. It was also observed
that the possibility of increasing the production per
unit land area under cultivation using supplemental
irrigation is little exploited. However, for the pur-
pose of precise water applications, it is essential to
understand fully cassava response to water deficit
as well as to define the water use and its regulation
under different field conditions. Most publications
reporting on the response of cassava to water defi-
cit were conducted under controlled environment
(Oguntunde 2005). The results of those experiments
require confirmation under natural environmental
conditions.
Drip irrigation with its ability of small and frequent
water applications have created interest in view of
decreased water requirements, possible increased
production, and better product quality (Connor
et al. 1981; Mohammed et al. 2006). Edoga and
Edoga (2006) reported that with drip irrigation,
the soil is maintained continuously in a condition
which is highly favourable to the crop growth. As
the applications are located close to the plant root
zone, the losses caused by through drainage or by
wetting inter-rows and ridges are minimised. The
report stated that drip irrigation generally compare
favourably with other types of irrigation both in terms
of crop yield and water conservation. Drip irrigation
has proved to be a success in terms of water and
increased yield (Bhardwaj 2001). Therefore, the
objective of this study was to examine the water use,
growth, and yield of cassava under different water
regimes using the drip irrigation technology that
can be easily transferred to the local farmers that are
involved in the cultivation of cassava in Nigeria.