Joni, F. R., Hamid, H., & Yanti, Y. (2020). Effect of Plant Growth Promoting Rhizobacteria (PGPR) on Increasing the Activity of Defense Enzymes in Tomato Plants. International Journal of Environment, Agriculture and Biotechnology, 5(6), 1474–1479. https://doi.org/10.22161/ijeab.56.9