Influence of Trichoderma Species on Biomass Production and Nutritive Value of Warm-Season Annual Grasses.

The cost of chemical fertilizers has increased exponentially in the last decade, impacting forage production. A way to mitigate this expense is by incorporating plant-promoting growth fungi such as Trichoderma spp. to increase nutrient uptake. The objective of this study was to evaluate the impact of Trichoderma spp. in biomass and nutritive value of warm-season annual grasses. The study was conducted at Mississippi State University in a Savannah Fine Sandy loam soil. The experimental design was a randomized complete block in a split-plot arrangement and replicated three times. The main plots were BMR forage sorghum, pearl millet, sorghum-sudangrass, and sudangrass) planted at a seeding rate of 25 lb PLS/ac. The subplots consisted of a control (C, control), Bio-inoculant (BI), Nitrogen (N), and N+BI. Seed was inoculated using two Trichoderma bio-inoculants supplied by Advanced Biological Marketing (ABM, Van Wert, OH) as liquid and powder formulations. Nitrogen was applied in at a rate of 100 lb N/ac/yr in split applications of 50 lb N/ac using urea ammonium sulfate (33-0-0-18S). Stand counts, LAI, SPAD, and NDVI readings were taken two weeks prior to the first harvest. Biomass was harvested twice in 2018 when plants reached 36-42 inches, ground to pass a 2-mm screen, and analyzed for nutritive value using NIRS and the grass hay equation developed by the Forage and Feed Testing Consortium (Hillsboro, WI). There was no forage species or treatment effect on seasonal biomass production. Control and Trichoderma treatments had lower NDVI, LAI, and SPAD readings values than nitrogen containing treatments. Nutritive value was significantly impacted by species and treatments. There was a treatment effect on CP (P<0.0001) while ADF, NDF, IVTDMD were affected by forage species (P < 0.0001; P < 0.0001; P = 0.0084) and treatment applications (P < 0.0001; P = 0.0001; P = 0.0003), respectively.