Abstract:
The conservation of water is crucial to sustainable agricultural production during dry season when there is little or no rainfall to improve crop production. Therefore, a field experiment was conducted at Teaching and Research Farm of the Department of Agricultural and Environmental Engineering, Federal University of Technology, Akure to evaluate the effects of different levels of irrigation on the growth, yield and water use efficiency of Okra under drip irrigation system.
Irrigation was applied when about 50% of field capacity has been depleted to bring the soil water to field capacity at 100 FIT (Full irrigation treatment) while 80, 60 and 40% of irrigation required to bring the soil water to field capacity were applied in treatments 80FIT, 60FIT and 40FIT respectively. The soil physical and chemical properties before and after planting were determined using standard procedures. The crop agronomic parameters which were determined include number of leaves, leaf area and leaf area index. The soil moisture content was determined using gravimetrical method. The yield components were determined at harvest and all agronomic and yield data obtained were subjected to statistical analysis using Excel and SPSS version 16. The highest agronomic parameters and yield were observed at 100 FIT. The highest Irrigation and Crop Water Use Efficiency of 0.041 and 0.0139 tons/ha.mm respectively was recorded at 60 FIT. The pod yield obtained with this treatment was 3.56 tons/ha and gives no significant difference at 5% level of significant to the yield obtained at 100 FIT using Tukey’s test. The crop evapotranspiration range for soil water balance was 3.5 to 6.0 mm/day and 2.7 to 5.8 mm/day for Aquacrop model respectively. This shows that either of the two methods can be used to calculate crop evapotranspiration. The linear relationship between irrigation and crop evapotranspiration gives R2 value of 0.9711. The linear relationship between the observed yield and the predicted yield by Aquacrop model gives R2 value of 0.9785 and this implies that the Aquacrop model is
