Drought and salinity are the major problems of Mediterranean agriculture. From an agronomic point of view, adaptation to stress is the ability of a plant to maintain reasonable yields. Various physiological traits related to stress tolerance (relative water content and chlorophyll content) and their impact on yield components were studied in Sorghum (Sudan Grass III).
Experimental design consists of five treatments: a control (100% ETM = 1 g / l), two water regimes (70% and 35% ETM) and two salt diets (3g / l and 6g / l).
Results showed that under moderate water stress, the relative water content and chlorophyll index have decreased slightly and penalized yield components. In response to severe stress, relative water content dropped from 89% to 78% and chlorophyll index fell by about 38% which acted unfavorably on all yield components.
Different intensity of salinity generates a slight increase in TRE but decreased chlorophyll content and size of main panicles.
All the parameters studied shows that there are positive correlations between plant water status and its yield: sorghum maintains high TRE under salinity and drought which indicating that this plant is of type "stay green" that keeps green and photosynthetically active leaves to have reasonable yields under abiotic stresses.