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.
