The effect of salicylic acid on alleviating the frost and drought stress on yield and related traits of maize hybrid SC400 (Zea mays L.)

Introduction Plants are affected by many unfavorable environmental factors and therefore crop growth and development is retarded. Cold and water stress impose a considerable damage to the economy and country’s agricultural production every year. Salicylic acid is of phenolic compounds which is found in many plants, and considered as quasi hormonal substance that plays an important role in the growth and development of plants. Salicylic acid plays an important role in resistance to environmental stresses. The aim of this study was to investigate the effects salicylic acid spraying on alleviating the chilling and drought stresses on yield and agronomic traits of maize single cross 400. Materials and methods This experiment was performed as a split-split plot in a randomized complete block design with three replications during 1394 in the greenhouse and the Research Farm of Faculty of Agricultural Ferdowsi University of Mashhad. The main plot of cold stress at two levels (non-stress and cold stress at 5ºC for 12 hours at 4th leaf stage), sub factors were three levels of irrigation (100, 75 and 50% of water requirement) and sub-sub plot was spraying with salicylic acid (non- (control) , 200 and 400 µM spraying After cold stress, seedlings of Single cross 400 were planted in the field. The plots were prapared with four meters length and three meters widths and row spacing of 75 cm with 75000 plants per hectare. At the end of the growing season to determine yield components, five plants were randomly taken from each plot from one square meter and biomass and kernel yield was recorded. MSTATC software implemented for statistical analysis and the means were compared using LSD test. Results and discussion The effect of drought stress and salicylic acid on the seed number per plant was significant. So that 100% irrigation %cause to improve 34.2% %in seed number per plant compared to 50% %of water requirement. Spraying plants with 200 and 400 µM improved the trait at a rate of 13.6 % compared to non-spraying (control). Effects of drought stress, salicylic acid and interaction of salicylic acid with drought on seed yield were significant. The treatment of 100% water requirement with 400 µM spraying with an increase of 54.3% showed the highest seed yield compared to 50% water requirements with spraying. In another study also corn foliar spaying with salicylic acid in flowering stage increased seed yield (Bayat et al., 2010). Effects of drought stress and salicylic acid and their interaction on biological yield were significant. The highest biological yield was obtained in 100% water treatment with 400 µM salicylic acid spraying with 55.2% higher biomass compared to 50% water treatment with similar salicylic acid spraying. Harvest Index in treatment of 400 µM salicylic acid spraying in irrigation conditions of 100% water requirement was 11.1% more than in irrigation conditions of 50% water requirement with the same salicylic acid spraying. Setter et al (Setter et al., 2001) similarly reported that corn grain yield reduced under drought stress. Conclusions The results of this study showed that cold stress did not have negative impact on SC400 corn hybrid on tested traits. But the drought stress reduced corn yield components (such as the number of seeds and rows in corn), seed weight, biological yield, seed yield, and harvest index. 400 µM salicylic acid applications can be significantly increased biological yield and seed yield SC400 corn.