It is well known that reducing the extent of damage to grain crops by root rot causing agents is one of the most effective ways to increase the yield of agricultural grain crops and improve their quality. These diseases are especially harmful for hard wheat, barley, soft spring wheat, and winter rye. Yield losses due to these diseases may reach 19–20% or more for wheat and 25–30% or more for barley. In order to assess the effectiveness of the bacteria isolated from earthworm coprolites as biological control agents, we conducted a series of field tests in Western Siberia from 2011 to 2015. We compared growth and development indicators of spring wheat (Triticum aestivum L., Irgina variety) and barley (Hordeum vulgare L., Acha variety) where seeds were treated with Bacillus cereus and two strains of Pseudomonas. The results showed that the inoculation increased the grain yield by 0.2–1.0 t ha−1 for spring wheat and by 0.3–1.8 t ha−1 for barley. In addition, the prevalence of the disease in spring wheat plants was significantly reduced from 18.1–61.1% in the control plots to 6.4–50.2% in the inoculated plots. Similarly, the index of root rot development decreased from 18.2–23.0% in the control plots to 13.2–15.8% in the inoculated plots. To understand the mechanism that induces the spring wheat resistance to fungal root rots under the influence of rhizobacteria, we investigated the effect on the guaiacol-dependent peroxidase activity. There was an inverse relationship between the peroxidase activity in wheat tissues and damage of plants caused by root rot agents indicating that the response of peroxidase enzymes to plant inoculation is a meaningful indicator that can be used to assess the potential of a particular strain as a biological agent for protecting spring wheat.
Part of the book: Grasses as Food and Feed