Periodic water stress effects on yield and quality of şeker dry bean with various growth habits

Agricultural water use is an essential issue and needs to be organized in a controlled approach. This study was conducted to determine the effect of periodic deficit irrigations on yield and quality of beans. In the present study, full irrigation (TS) and periodic deficit irrigations (S1, S2, S3) were applied to four bean varieties with bush (Erzincan Şeker, Kurtuluş), semi-climber (Gündoğan) and climber (Bulduk) growth types. The field trial was conducted in Tokat Gaziosmanpaşa University Agricultural Application and Research Center in 2023 with three replications according to the split-plot experimental design in randomized blocks. In the study, flowering period were between 43.0-50.1 days, pod formation 50.1-60.1 days, leaf temperature 30.1-37.8 °C, SPAD index 33.6-44.4, maximum PSII quantum efficiency 0.591-0.752, maturity period 93.3-114.0 days, plant height 58.5-318.3 cm, number of pods per plant 14.3-48.1, number of seed per pod 3.1-6.0, biological yield 758.3-3954.3 kg/ha, grain yield 285.3-578.3 kg/ha, harvest index 12.6-44.5%, hundred seed weight 32.8-57.5 g, protein content 25.2-28.3%, water uptake capacity 34.0-67.0%, water uptake index 102-115%, cooking time 15.0-20.1 min and husk percentage 6.0-7.3%. The highest grain yield was determined in cultivars Kurtuluş and Bulduk. In water stress treatments, the highest grain yield was observed in S2, i.e. water stress at the beginning of flowering - pod formation and full irrigation after pod formation. When considered periodically, the stress applied only during the flowering period caused more tolerable results in bean plants than the stress applied only during the pod formation period. In S 2 treatment, 14% water was saved and 16% higher yield was obtained than TS treatment. The results suggest that S2 treatment is the most suitable irrigation program for more bean production and a more sustainable environment.