Assessment of crop water stress index and net benefit for surface- and subsurface-drip irrigated bell pepper to various deficit irrigation strategies
Yeşim Bozkurt Çolak, Attila Yazar, M. Yıldız, Servet Tekin, Engin Gönen, Adnan Al-ghawry
Abstract
Abstract This study addresses the assessment of crop water stress index (CWSI) of bell pepper ( Capsicum annuum L.) and net income generated under regulated deficit irrigation (RDI), conventional deficit irrigation and partial root-zone drying (PRD) and full irrigation (I 100 ) using surface- and subsurface-drip systems (DI and SDI) during 2016 and 2017 in the Mediterranean region. The experimental design was split-plots with four replications. RDI was supplied with 50% of I 100 during vegetative stage until flowering, then received 100% of crop water requirement. PRD 50 received 50% of I 100 , but from alternative laterals each watering. The results revealed that CWSI was correlated significantly ( P < 0.01) and negatively with yield, yield per plant, total soluble solid, ETa, fruit weight and plant height indicating that yield of bell pepper declined with increasing CWSI values ( P < 0.01). Bell pepper should be irrigated at mean CWSI value of 0.20 without any yield reduction. CWSI in the RDI and I 75 treatments were slightly greater than 0.20. Irrigation treatments had significant effect on yield and quality traits. The highest total soluble solutes were found in PRD 50 and I 50 . The DI I 100 treatment generated the highest net income followed by the SDI I 100 and RDI. In conclusion, RDI and I 75 appear to be good alternatives to I 100 for sustainable bell pepper production in the Mediterranean region.