THIOUREA APPLICATION PROTECTS MAIZE FROM DROUGHT STRESS BY REGULATING GROWTH AND PHYSIOLOGICAL TRAITS

Abstract

Drought stress at any stage of maize causes a marked reduction in growth and yield formation. Thiourea (TU), a well-known plant growth regulator, can ameliorate the abiotic stress by regulating the crop growth and development; however, little is known regarding its role in improving drought tolerance in maize. Therefore, this study was performed to examine the effectiveness of TU in reducing the negative effects of drought stress on maize crop. The treatments were consisted of three drought levels, control (normal irrigation), skip irrigation at the vegetative stage, and skip irrigation at the reproductive stage, and four TU concentrations, water spray, 400, 800, and 1200 mg L-1. The findings showed that drought stress decreased plant height, cob diameter, grain per cob, chlorophyll content, relative water content (RWC), biological and grain yield, and harvest index. Nonetheless, TU application, particularly at 800 mg L-1, significantly increased plant height, cob and stem diameter, grain per cob, chlorophyll (a and b) and RWC, biological and grain yield, and harvest index. The positive influence of TU application on the growth, yield and yield parameters was remained as 800 mg L-1 > 400 mg L-1 > 1200 mg L-1 > water spray (Figure 4d). In conclusion, TU application at 800 mg L-1 is recommended to mitigate effects of drought stress in maize to get the satisfactory production.