Management of sorghum grain mold through induced resistance mechanism using foliar spray of Pseudomonas fluorescens strains and non-conventional chemicals: a field study

Abstract

The study involved in-vitro and field studies using Pseudomonas fluorescens strains and some non-conventional chemicals for sorghum grain mold management. The culture filtrate of P. fluorescens strains PF-1 and PF-2 inhibited spore germination (p?<?0.001) and mycelial growth of grain mold fungi. Also, tested chemicals and commercial fungicides showed significant mycelial growth inhibition (p?<?0.001). PF-1, PF-2, ZnSO₄·7H₂O, salicylic acid and propiconazole were potentially effective and hence were tested in field (by foliar spraying). Two set of experiments were conducted simultaneously using naturally and artificially (Fusarium challenged) induced infected sorghum panicles. The lowest infection (score 4.2) was recorded with propiconazole. Disease severity was well controlled by PF-1 and PF-2, compared to ZnSO₄·7H₂O and salicylic acid. Furthermore, disease control was validated by determining total phenolic, flavonoid content and differentially induced phenolic acids (HPLC analysis) in harvested grains. Additionally, results of biochemical-traits, compatibility studies and antibiotic sensitivity of strains were found to be favourable.