76 Molazem and Bashirzadeh Int. J. Biosci. 2014 RESEARCH PAPER OPEN ACCESS Effects of salicylic acid and salinity on growth of maize plant (Zea mays L.) Davar Molazem * , Ali Bashirzadeh Department of Agriculture Astara Branch, Islamic Azad University, Astara, Iran Key words: Salicylic acid, carotenoids, maize, Salinity. http://dx.doi.org/10.12692/ijb/4.9.76-82 Article published on May 07, 2014 Abstract To evaluate the effect of salt stress and salicylic acid application on growth and physiological traits of maize varieties, an experiment was conducted in factorial split plot based on RCBD design with 3 replications in research farm of Islamic Azad University of Ardebil branch during 2012-13. Salt stress factor including three levels (control, 50mM and 100mM NaCl) and acid salicylic (control, 1mM and 2mM). Results from the experiment showed that, between different salinity between different salinity in carotenoid, chlorophyll a+b, chlorophyll content and proline were significantly different. Effect of salicylic except for stem diameter was not significant for all traits. Interactive effects of salinity in salicylic on proline was significant at the 5% level. There was no significant difference in leaf length between salinity, but salinity decreased the amount of leaf length was 100 Mm NaCl in soil. The lowest of Leaf length was observed at 100 mM salt and 2 mM salicylic acid concentration. Chlorophyll content was measured by chlorophyll meter showed that with increasing salinity, chlorophyll content also show a significant decrease. The maximum stem diameter at the concentration of 100 mM salt, and 1 mM salicylic acid was observed in 640Ns variety (26/83mm). The highest amount of carotenoids in the leaves of salt-zero (control) was observed with increasing salt were significantly lower. Between leaf length with chlorophyll content, total chlorophyll (a+b) and carotenoid was observed significant positive correlation. There was a significant positive correlation between chlorophyll content with total chlorophyll, carotenoids and stem diameter. * Corresponding Author: Davar Molazem  d.molazem@iau-astara.ac.ir International Journal of Biosciences | IJB | ISSN: 2220-6655 (Print) 2222-5234 (Online) http://www.innspub.net Vol. 4, No. 9, p. 76-82, 2014