Exogenous Application of Gibberellic Acid Improves the Maize Crop Productivity Under Scarce and Sufficient Soil Moisture Condition

Abstract

Drought stress creates imbalance or deficiency of some growth regulators in plants, which leads toward reduced crop yield. Gibberellic acid is one of the most important growth regulators in plants, which improve drought tolerance in plants under optimum concentration. A field experiment was conducted under exogenous application of gibberellic acid under normal or drought condition and with or without gibberellic acid application. Crop growth and yield parameters were assesses during the experimentation. Study revealed that crop reduced growth in term of leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), net assimilation rate (NAR) and total dry matter (TDM) under drought condition, while these parameters were improved with gibberellic acid application. Similary, improved growth rate resulted in better performance of yield attributes (cob length, cob diameter, grains per cob, grain weight and yield). Gibberellic acid application improved the crop performance at optimum irrigation, as well as under reduced irrigation. Although highest crop yield was recorded with gibberellic acid application under optimum irrigation level, while its application under drought stress improved crop tolerance and resulted in better crop yield, similar to optimum irrigation level. Exogenous application of gibberellic acid not only improved the drought tolerance in maize, but also increased the crop yield under normal condition.