Abstract:
Soil water is the major limiting factor to the production of Corchorus olitorius
especially during the dry period. Two field trials (experiments I and 2) were conducted
between March and April, 2000 and between September and October, 2000 at the
Experiment farm of the Department of Agricultural Engineering, Federal University of
Technology, Akure. The aim was to quantify the water use pattern, water balance and the
yield of C. olitorius under six treatments based on Irrigation water and fertilizer
applications. The treatments were: Irrigation at full pan evaporation plus 100 kgN/ha,
fertilizer, Irrigation at full pan evaporation plus zero kgN/ha fertilizer, Irrigation at ~ Pan
evaporation plus 100 kgN/ha fertilizer; Irrigation at ~ pan evaporation plus zero kgN/ha
fertilizer; Irrigation at ~ pan evaporation plus 100 kg/haN fertilizer, Irrigation at 12 pan
evaporation plus zero kgN/ha fertilizer. Crop water use (ET) differed among treatments and it reflected an influence of irrigation water application and hence soil moisture availability for crop growth and yield. The highest water use (7.1 mm/day and 11.8 mm/day) were observed at 35 DAP and 14 DAP during the first and second experiments, respectively. The highest WUE (19.80 g/rrr' of water) was obtained from irrigation at full pan evaporation plus 100 kgN/ha at the 7 WAP in block A during the second experiment. In addition, the result showed that nitrogen application was beneficial to the crop in terms of growth and yield such as, higher leaf number, fresh and dry matter production.
Biomass yield (dry basis) was highest at 7WAP (9.63 tonlha) in irrigation
treatment at full pan evaporation plus 100 kgN/ha during experiment 2. A linear
Regression model for Water-Nitrogen- Yield was established: equation Y = 0.1503ET -
6.8851 (linear) and Y = 0.0011ET2 + 0.622ET - 53.97 (polynomial) gave the best
relationship but correlation (R2 = 0.836) was highest when data from treatment without
fertilizer application were used. The result obtained in this study would be useful in water stress studies which can be used for irrigation scheduling and yield prediction.
