ABSTRACT
The main problem in the production of crops in arid and semi-arid regions of the world is the lack of water and its effect on the plant in the form of drought stress. Cultivation of key crops such as corn, which also requires a lot of water, is not possible in these areas except by applying water consumption management methods. Among the most important of these methods is deficit irrigation. The effect of deficit irrigation on relative water content (RWC), malondialdehyde (MDA), compatible osmolytes (proline and soluble sugars), antioxidant enzymes, and yield was studied in three baby corn cultivars in a field experiment using a randomized complete block design (RCBD) with split-plots and three replications. Three levels of deficit irrigation (0, 20, and 40% deficit) constituted the main plots and three cultivars of baby corn (Challenger, Basin, and Passion) constituted the sub plots. Analysis of variance showed that deficit irrigation had a significant effect on all variables. Cultivar (Challenger, Basin and Passion) had a significant effect on proline (0%, 41.5% and 73.2%), carbohydrates (23.9%, 15.4% and 0%), and MDA content (0%, 26.1% and 41.2%), as well as peroxidase (POD) (0%, 136.1% and 227.9%) levels respectively. The interaction between deficit irrigation and cultivar had a significant effect on proline, carbohydrates, and POD. RWC decreased (26.9, 6.5 and 0%) with increasing irrigation deficit (0, 20 and 40%) respectively while proline (0, 23.7 and 64.8%), carbohydrates (0, 29.7 and 34.09%), catalase (CAT) (0, 20.8 and 70.1%), and POD (0, 55.05 and 113.2%) increased under the same conditions. Carbohydrate content was higher in the Basin and Challenger cultivars (21.71 and 19.07) and proline (145.9), POD (193.9), and MDA content (8.53) were higher in the Passion cultivar. Among the studied cultivars, the highest yield was achieved by the Passion cultivar (37.02 and 62.9% more than Challenger and Basin cultivars respectively). In general, the results showed that drought stress caused an increase in compatible osmolyte content and the activity of antioxidant enzymes. However, this increase could not offset the effects of drought stress on yield in the 40% deficit treatment.
