Effect of drip irrigation management on yield and quality of field grown green beans

This study examines the effects of different irrigation regimes on yield and water use of green beans irrigated with a trickle system under field conditions in 2003 in the Mediterranean region of Turkey. Irrigation regimes consisted of four irrigation intervals (I1: 13-17 mm, I2: 28-32 mm, I3: 43-47 mm and I4: 58-62 mm of cumulative pan evaporation) and three plant-pan coefficients (Kcp1=0.50, Kcp2=0.75 and Kcp3=1.00) were evaluated. Both Kcp and irrigation intervals influenced significantly green bean yields. Irrigation intervals varied from 2 to 3 days in I1, 5 to 7 days in I2, 8 to 9 days in I3 and 10 to 12 days in I4 treatments. Maximum and minimum yields were obtained from the I1Kcp3 and I4Kcp1 treatments as 20,558 and 12,243 kg ha−1, respectively. As the Kcp value decreased the total yields in each irrigation interval also decreased. However, with the lower irrigation frequency (I4), lower yields were obtained with all Kcp coefficients. Seasonal water use values in the treatments varied from 253 mm in I4Kcp1 to 338 mm in I1Kcp3. Significant linear relations were found for green bean yield and total water use for each irrigation interval. Irrigation intervals resulted in similar water use in the treatments with the same Kcp value. Water use efficiency (WUE) and irrigation water use efficiency (IWUE) values were significantly influenced by the irrigation intervals and plant-pan coefficients. WUE ranged from 4.14 kg m−3 in I4Kcp3 to 6.16 kg m−3 in the I1Kcp2. The maximum IWUE observed in I1Kcp1, minimum IWUE were in I4Kcp3 treatment. The yield response factor (ky) was found to be 1.23 for whole growing season. Both Kcp coefficients and irrigation frequencies had significantly different effects on quality parameters such as fresh bean length, width, number of seed per pod and 100 fresh bean weights. In conclusion, I1Kcp3 irrigation regime is recommended for field grown green bean in order to attain higher yields with improved quality.