Growth and Physiological Responses of Maize (Zea mays L.) under Drought Stress at Different Development Stages

Drought stress was a main problem of maize production in Thailand. This study aimed to evaluate the effect of drought stress at different development stages and maize varieties (Zea mays L.) on growth, physiological responses, and grain yield to maintain maize production. The experiment was arranged in split-plot in a Randomized Completely Block Design (RCBD) with four replications. The main plot was control (well-watered) and drought stress at different development stages (the vegetative phase (V5), before the reproductive phase (V12), and the grain filling phase (R3)). The sub-plot consisted of four maize varieties: TS1004, NS3, SW4452, and NK6248. Drought stress during the vegetative phase (V5) and before the reproductive phase (V12) was found to be a susceptible stage for maize because grain yield (GY) was decreased by the loss of crop growth rate (CGR) and total soluble sugar content (TSC) and it accumulated proline content. The NK6248 variety was found to be the most suitable for maize production because it had the highest grain yield (GY) and crop growth rate (CGR). In addition, it had low proline content (PC) under drought stress. In summary, under drought stress, it is advisable to select the NK6248 variety for crop production and avoid drought stress in the vegetative phase (V5) and before the reproductive phase (V12) because a mechanism by which maize could maintain its production of this study was the accumulation of total soluble sugar content to decrease proline content under drought stress condition.