Does Exogenous Vitamins Improve the Morphophysiological Condition of Sugarcane Subjected to Water Deficit?

Most of the areas cultivated with sugarcane around the world are subject to a period of water deficiency, reducing the productive potential of the crop. Management techniques that allow a greater resistance of plants concerning this stress can be an important tool for the better reestablishment of plants after the drought period. Thus, in the present study, the effects of exogenous application of thiamine and nicotinamide in sugarcane plants submitted to water deficit in the early stages of development were considered. The treatments tested were: T1 = control; T2 = 100 mg nicotinamide L −1 ; T3 = 100 mg thiamine L −1 ; T4 = 50 mg nicotinamide + 50 mg thiamine L −1 ; T5 = 100 mg nicotinamide + 100 mg thiamine L −1 , which were applied prior to the imposition of stress. After 90 days of cultivation, we found that treatments T3 and T4 provided better adaptability of plants to water deficit stress, improving the physiological conditions of gas exchange and stomatal functionality. Thus, we conclude that the isolated application of thiamine (100 mg L −1 ) and its combination with nicotinamide, in a concentration of 50 mg L −1 , can be beneficial to the photosynthetic apparatus and the stomatal morphology of sugarcane plants subjected to a period of water deficit.