Abstract:
To combat the problem of
food scarcity and insecurity in areas
affected by salinity, crop varieties that are
tolerant to the stressful conditions should
be selected and used. Therefore, this study
was carried out to investigate and know
the effects of salinity stress on growth and
yield of three cowpea cultivars to select
the best salinity tolerant cultivar for
optimum yield production. To achieve
this, three separate experiments were
concurrently carried out using ITIOK-298-15, IFE BROWN and
SAMPEA 11 cowpea cultivars in the
glass house of the Faculty of Agriculture,
University of Ilorin, Nigeria. The salinity
levels tested in each of the cultivars were
0mM (the control), 50mM, 100mM and
200mM sodium chloride (NaCl). The
imposition of salinity stress was for a
period of two weeks at maturity because
this stage is the most sensitive stage for
any crop grown under any environmental
stress. The experiments were laid out in
randomized complete block design
(RCBD) with four replications. Data
collection was centred on root length,
plant height, number of leaves, leaf area,
dry mass, final yield, chlorophyll content
of leaves, crude protein and crude fat
contents. From this work, it was found
that 200mM NaCl decreased the final
yield by 51% in ITIOK-298-15, 73% in
IFE BROWN and 100% in SAMPEA-11
compared to the control. Furthermore,
100mM NaCl reduced crude protein
contents of the leaves by 6% in ITIOK-
298-15, 10% in IFE BROWN and 17% in
SAMPEA-11 compared to the control.
From the above results, it was found that
ITIOK-298-15 was the most tolerant
cultivar while SAMPEA-11 was the most
susceptible cultivar to salinity stress. It is,
therefore, recommended (subject to
further confirmation) that ITIOK-298-15
cultivar, which is the most promising
cultivar of the three cultivars
experimented, be used in cowpea
production in saline environments of the
Southern Guinea savannah ecological
areas of Nigeria.
