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 (1(1): 13-17 mm, 1(2): 28-32 mm, I-3: 43-47 mm and I-4: 58-62 mm of cumulative pan evaporation) and three plant-pan coefficients (K-cp1 = 0.50, K-cp2 = 0.75 and K-cp3 = 1.00) were evaluated. Both K-cp and irrigation intervals influenced significantly green bean yields. Irrigation intervals varied from 2 to 3 days in 11, 5 to 7 days in 12, 8 to 9 days in 13 and 10 to 12 days in 14 treatments. Maximum and minimum yields were obtained from the I-1 K-cp3 and I4Kcp1 treatments as 20,558 and 12,243 kg ha(-1), respectively. As the K-cp value decreased the total yields in each irrigation interval also decreased. However, with the lower irrigation frequency (14), lower yields were obtained with all K, 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 K-cp 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 I-1 K-cp2. The maximum IWUE observed in I1Kcp1, minimum IWUE were in I4Kcp3 treatment. The yield response factor (k(y)) was found to be 1.23 for whole growing season. Both K-cp 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, I-1 K-cp irrigation regime is recommended for field grown green bean in order to attain higher yields with improved quality. (C) 2004 Elsevier B. V. All rights reserved.