The Reaction of Valerian to the Application of Bio-Fertilizers under Drought Stress

The goals of study were to recognize the effect of bio-fertilizers on some quantitative and qualitative traits of Valerian under drought stress.  

The experiment was conducted as split plot based on randomized complete block design with three replicationes at the Research Farm of Urmia during two successive seasons of 2015-2016 and 2016-2017. The test factors included drought stress at three levels of irrigation 60, 90 and 120 mm evaporation from pan class A as the main factor and inoculation with bio fertilizer in eight levels including: 1-control (non-inoculation), 2-mycorrhiza, 3-Azotobacter, 4-Azospirilum, 5- combination of Azotobacter and Azospirilum, 6- combination of Azotobacter and Mycorrhiza, 7- combination of Azosperilum and Mycorrhiza, 8-Azotobacter, Mycorrhiza and Azospirilum as subplots.  

The results showed that with increasing drought stress, the plant height, root dry weight, shoot dry weight, root length, root volume, phosphorus and potassium decreased, and the percentage of valeric acid increased. The application of bio-fertilizers increased all studied traits except of the Valernic acid content.  

Based on the results of this study, with the application of bio-fertilizers, the effects of drought stress on the valerian can be modulated and it has been used in pursuit of the goals of sustainable agriculture.