Response of Bell-Pepper (Capsicum annuum L.) to Salt Stress and Deficit Irrigation Strategy under Greenhouse Conditions

This study was conducted to examine the effect of two levels of irrigation water salinity (electrical conductivities "EC" of 3.4 and 0.9 dS m(-1)) and three levels of deficit irrigation (DI), specifically 60%, 80% and 100% of the maximum crop evapotranspiration (ETc); at three growth stages (vegetative, reproductive and fruiting) on the growth, yield and quality of bell-pepper (Capsicum annuum L. 'Taranto'). The experiments were carried out during the 2010 and 2011 growing season under greenhouse conditions. Higher level of irrigation water salinity reduced the total yield by 35%, however, improved some fruit quality characteristics, particularly total soluble solid (TSS), total sugars (TS) and vitamin C compared to non-saline water. The total yield increased significantly when the amount of irrigation water was reduced from 100% to 80% ETc during the vegetative or fruiting stage. Water use efficiency (WUE) also increased significantly by decreasing the amount of irrigation water. The interaction between water salinity and deficit irrigation treatments exerted significant effects for most of the studied traits. The higher level of irrigation water significantly mitigated the deleterious salinity effects. Deficit irrigation at vegetative or fruiting growth stages at a rate of 80% of the ETc using non-saline water significantly increase the total yield as well as enhance WUE and fruit quality with 10% saving in the total amount of irrigation water. Therefore, this treatment could be recommended for bell-pepper grown under greenhouse conditions. The vegetative and fruiting growth stages seem to be more tolerant to deficit irrigation than the reproductive stage.