Effect of drought stress and aerosols on yield and some physiological traits of soybean (Glysin max L.)

Recent droughts, in addition to creating drought stress, have caused the phenomenon of aerosols, especially in the west of the country. The effect of drought stress and aerosols on the physiological characteristics of soybean (Glysin max L.) Kosar cultivar was investigated in an experiment based on a randomized complete block design as split plots with 4 replications in summer cultivation for two years. Drought stress through irrigation after 60 (optimal irrigation), 90 and 120 mm evaporation from Class A evaporation pan as the main factor and spraying of aerosols in three levels of non-application (control) and application of 50 and 100 mg in cubic meters of air were placed in subplots as simulations. The results showed that severe drought stress significantly reduced the amount of chlorophylls a and b, catalase of shoots and roots. The amount of light of the canopy floor and the relative water content of the flag leaf (from 89 to 70%), plant height, yield components and grain yield (from 2653 to 1167 kg per hectare) compared to the control treatment, but soluble sugars, proline content, shoot and root peroxidase and leaf temperature (from 18.4 to 27.6 °C) increased significantly. Although the effect of aerosols on any of the traits was not significant, but with increasing the concentration of aerosols, grain yield decreased linearly and proline content increased linearly. Overall, it was found that drought stress significantly reduced soybean production, but low aerosols settling on soybean leaves did not cause serious damage to the plant photosynthetic system and ultimately seed production due to leaves waxy nature.