Effect of cytokinin and auxin regulators on some characteristics of grain maize under different planting patterns in salinity conditions

A large part of lands under maize cultivation have various degrees of salinity. To study the effects of spraying time of cytokinin and auxin regulators on some characteristics of grain maize (SC704) under different planting patterns in salinity conditions, an experiment was carried out as split plot-factorial in randomized complete block design with three replications in Bushehr Agricultural and Natural Resources Research Center, in 2013. Planting pattern (ridge planting, double rows and furrow planting) was considered as the main factor and spraying time of cytokinin (control, V5-V6 and V8-V10 stages) and auxin (control, silking and two weeks later) with 50 and 10 mg.L-1, respectively, in factorial as the sub-factor. The results showed that planting pattern had the highest number of leaves, LAI, SPAD, Fm, Fv/Fm and grain yield. Double rows and furrow planting increased grain yield to 24.9% and 45.8%, respectively. Cytokinin application in V8-V10 stage increased LAI, RWC, SPAD, Fm and Fv/Fm. The lowest Fm was observed with cytokinin application in the V8-V10 stage and the highest SPAD and Fv/Fm and the lowest Fm were obtained with application of auxin in the silking stage. Application of auxin in silking stage increased grain yield (19.7%). Since the highest SPAD and Fv/Fm were produced under furrow planting with cytokinin application in V8-V10 stage and auxin in silking stage, where the highest grain yield was obtained, the spraying time together with balancing regulators under the correct planting pattern can be main factors in salinity tolerance of corn.