Yield and morpho-physiological traits of tobacco (Nicotiana tabacum L.) as affected by azotobacter, mycorrhizal symbiosis and biochar application

Abstract

The present study was performed to evaluate the effect of mycorrhizal symbiosis and azotobacter with the application of biochar on tobacco growth parameters, yield and nicotine content under rainfed conditions for two growing seasons (2016-2017 and 2017-2018). The factorial experiment was performed based on a randomized complete block design with four replications and three factors including biochar at three levels (0, 4 and 8 ton/ha), mycorrhizal fungi and Azotobacter chroococcum each one at two levels (without and with application). Results showed that biochar application had a significant and positive effect on all evaluated parameters. However, there was no statistically significant difference between 4 and 8 tons per hectare of biochar in yield. Mycorrhizal symbiosis had a significant effect on relative water content. Application of azotobacter had a positive and significant effect on growth parameters, yield and nicotine content under rainfed conditions for two growing seasons (2016-2017 and nicotine content. The greatest effect of azotobacter with a 17% increase was on leaf nicotine content. Whereas tobacco dry yield in rainfed conditions is lower, the combined use of biochar and these biofertilizers can be considered a desirable solution. Then in terms of economic aspects, the use of 4 tons biochar per hectare along with the use of mycorrhiza and azotobacter to achieve acceptable yield while maintaining chemical quality in tobacco farms is recommended.