EFFECT OF ANTITRANSPIRANTS ON GROWTH, YIELD, ITS COMPONENTS AND WATER PRODUCTIVITY OF SUNFLOWER UNDER WATER STRESS CONDITION

A field experiment was carried out at Itay El-Baroud Agricultural Research Station, El-Behera Governorate, Egypt to study the effect of three levels of water treatments, i.e. full irrigation: 100% ETc (crop evapotranspiration), moderate stress: 75% ETc and high stress: 50% ETc and three antitranspirants, i.e. kaolin, MgCO3 and flaxseed oil on growth, yield, its components, some physiological traits and water productivity of two sunflower cultivars, i.e. Sakha 53 and Giza 102 during the two growing seasons of 2017 and 2018. Results indicated that increasing soil moisture stress up to 50% ETc significantly decreased (p˂0.05) sunflower cultivars growth, yield, its components and some physiological traits. However, leaf temperature and proline content significantly increased (p˂0.05) when plants exposed to high stress treatment compared to full or moderate treatments. Sakha 53 cv. exceeded Giza 102 in shoot dry weight, seed and oil yields ha-1, yield components, chlorophyll a, b, a+b and seed protein. Sunflowers plants sprayed with antitranspirants under water stress significantly increased (p˂0.05) growth, yield, its components, some physiological traits and irrigation water productivity (IWP) compared with untreated plants. Results also indicated that lower yield reductions (RYD %) were recorded from spraying Sakha 53 by MgCO3 under moderate stress in the first and second seasons. It could be concluded that kaolin or MgCO3 application can ameliorate negative effects of water stress on sunflower growth, yield, its components, seed quality and increased water productivity.