Simultaneous Effect of Salinity and Drought Stress on Morphological Characteristics and Yield of Turnip

The simultaneous effect of salinity and drought stress are among the major factors that limit agricultural production in many parts of the world, especially in arid and semi-arid regions. Accordingly, a greenhouse research was carried out to study the simultaneous effect of salinity and water stress on yield and yield components of turnip (Purple Top White Globe var.) in Kashmar region. The experiment was performed as factorial arrangement in completely randomized design with three replications including two factors; salinity and irrigation water volume. Treatments consisted of four levels of water salinity (S1=0.7, S2=4, S3=8 and S4=12 dS/m) and three levels of water (W1=100%, W2=75% and W3=50 percent of water requirement), which were applied in a sandy-loam soil texture. The results showed that effects of salinity and water stress and their interaction were significant on biomass, shoot wet biomass, tuber and leaf dry weight (P<0.01). W1S1 and W2S1 treatments had higher biomass than the others. In all of the salinity levels, there was no significant difference between biomass in W1 and W2 irrigation levels. Based on the results of this research it could be concluded that turnip is more sensitive to salinity stress than drought stress. In other words, the results showed that the best level of salinity to reach the maximum biomass was S1. Therefore, the best treatment recommended for turnip planting in Kashmar region is W2S1.