Abstract:
Water stress affects plant
growth and crop productivity in the vast
semi-arid and arid regions of Iran. The
present study was aimed at investigating the
effect of drought stress and super absorbent
polymer (SAP) on the osmotic adjustment
and carotenoid content of sunflower (cv.
Master) under field condition. The
experiment was carried out as a split plot
based on randomized complete block design
with three replications. Three irrigation
levels (irrigation after 6, 10 and 14 days)
and five amount of super absorbent polymer
(SAP) (0, 75, 150, 225, 300 kg/ha) were set
as main and sub factors, respectively.
Polymer was added in fourteen leaves stage
of sunflower to soil in deepness of roots
development (by mixing with soil) and at
this same stage drought stress was
applied.The results showed that effect of
different rates of super absorbent polymer
and water stress in all traits were significant
(P<0.001) as well as their interactive effect
of two mentioned factors were significant (P
<0.001).Drought stress significantly
increased carotenoid content. Drought stress
caused an increase in the concentration of
soluble sugar and proline content in the
leaves of sunflower. These results indicated
that lowest amount in proline and soluble
sugars accumulation were achieved at 300
kg ha-1 polymer compared with the control
(without polymer) in all rates of water even
under drought stress conditions.Our results
showed that SAP can absorb and retain
extremely large amounts of water, so
protects the plants against drought.
