عنوان مقاله [English]
The effect of anti-transpiration substances on dry matter remobilization of maize cv. SC-500 under water stress, a split plot experiment in randomized complete block design with three replications was conducted in Hamedan during 2009 growing season. Three irrigation treatments including irrigation after 60, 90 and 120 mm evaporation and anti-transpiration substances including 0.5 mM salicylic acid (SA), 50 ppm paclobutrazol (PBZ) and control were considered as main- and sub-plots, respectively. The anti-transpiration substances were sprayed on plants at 6 and 8 leaf stages. Results showed that SA under irrigation after 90 mm evaporation increased 20.15% and 34.59% and under 120 mm evaporation increased 23.55% and 37.95% of the remobilization of dry matter from stem and leaf, respectively, compared with control treatment. PBZ treatment also increased 13.33% and 16.51% of the remobilization of dry matter from stem and 27.73% and 29.96% from leaf under 90 and 120 mm evaporation, respectively, compared with control. Furthermore, dry matter translocation efficiency and contribution significantly increased under both 90 and 120 mm evaporation than the control, but under 60 mm evaporation, SA treatment decreased and PBZ treatment increased the rate, efficiency and contribution of the remobilization of dry matter from stem, leaf and spathe. SA increased 15.84%, 20.82% and 29.74% of the grain yield under 60, 90 and 120 mm evaporation compared with control, respectively, but the highest grain yield (10267.36 kg.ha-1) was achieved by SA under the 60 mm evaporation. In contrast, PBZ under the 60 mm evaporation decreased and under the 90 and 120 mm evaporation increased grain yield (17.52% and 21.65%, respectively), compared to control. Therefore, the application of salicylic acid and paclobutrazol anti-transpiration substances are recommended for alleviating effects of water stress in maize plants.