Effect of effective microorganisms on wheat growth under salt stress condition

Effective microorganisms (EM) are important beneficial fungi and bacteria mixed culture that is used as an inoculant to improve soil quality and health, enhance plant growth, yield, and quality. This study was conducted to evaluate the effect of inoculating various concentration of EM (50, 100 and 200 mL L-1) on growth of wheat (Triticum aestivum L.) seedlings, grown under NaCl regime (6 dS m(-1)), including fresh and dry weight, chlorophyll content, maximum fluorescence yield (F-m), variable fluorescence yield (F-v), optimum photosystem II (PSII) quantum yield (QY) and ratio of fluorescence decline in steady state (RFD). Seedlings subjected to salt treatment exhibited significantly 60% and 30% reduction in both fresh in dry weight; respectively, however, when seedlings under saline condition were treated with EM at both 50 and 100 mL(-1), fresh weight was increased two folds. However, for both dry weight and plant length, EM at 100 mL(-1) showed the highest significant values compared to salt treated seedlings (40% and 18%, respectively). Salinity treatment reduced significantly chlorophyll content, F-v/F-m and QY, however, the addition of EM at 200 mL L-1 alleviated the effect of salt stress on photosynthetic parameters. The application of both 100 and 200 mL L-1 alleviated the salt effect resulted in a similar chlorophylls content as the control (36.23 and 34.12 SPAD units) respectively. EM application at 200 mL L-1 significantly lowered electrical conductivity from 14.35 to 10.29 dS m(-1) of the media. In conclusion, EM can be used to counter act salt effect in soil and improve growth behavior of wheat plants under salinity conditions.