Determination of Crop Coefficient of Okra Plant in Forest-Savannah Agro-ecology of Nigeria

Abstract

Effective irrigation planning and management requires basic information on water requirement and
coefficient of the crop. This study was designed to investigate crop coefficient (Kc) of okra grown in mini-
drainage lysimeter during 2019 and 2020 late seasons. Five irrigation treatment blocks were adopted for five
mini lysimeters used for the experiment. The treatments are, Ttwice daily water applicaon ( ), Daily water1
applicaon ( ), every other day ( ), two days interval ( ) and control ( )T T T T . Climatic variables were obtained2 3 4 5
for the determination of reference evapotranspiration (ETo) using the FAO-Penman Monteith model. The
values for the crop evapotranspiration (ETc) was determined from the lysimeter using the soil water balance
method on daily basis and the crop factor (Kc) was estimated from the ratio of ETc / ETo. The result indicated
that both growth attributes of okra were significantly influenced by varying water application in all treatments.
Okra planted with treatment T (twice daily irrigation) produced the highest vegetative growth, while that1
subjected to no irrigation (Tc) has the least of vegetative growth irrespective of the year of planting.
Consequently, yield parameters of okra subjected to treatment T (daily irrigation) gave statistically superior2
yield characteristics to all other treatments and the least with Tc (zero irrigation). The okra Crop
Evapotranspiration( ETc) values ranged from 46.8 to 189.6 mm. Higher ETc values were recorded during
flowering stages as compared to the values obtained in other parts of the crop life cycle or growth stages. The
okra crop coefficient (Kc) at emergence, establishment, flowering and maturity stages are 0.53, 0.94, 1.86 and
0.77 respectively. Crop coefficient (Kc) values obtained indicated that requires more waterokra plant
application during the flowering stages than at emergence and maturity stages. It is therefore recommended
that Kc developed from this study be used for irrigation scheduling and developing water budgeting
procedures for irrigation for optimum okra production during the growing season of forest-savannah agro-
ecology of Nigeria in the face of current climate change and variability.