Influence of Trichoderma Application on Seed Germination and Seedling Biomass of Jamaican Scotch Bonnet Peppers

Jamaican Scotch Bonnet peppers, which exhibit inherent quality attributes such as flavor and pungency, could become a potential niche market for small farmers on the Delmarva Peninsula. However, the crop is highly susceptible to numerous soil-borne pathogens that may significantly affect yield. Beneficial microorganisms, notably Trichoderma, are plant symbionts that maybe used as seed treatment to control diseases and enhance plant growth and yield. This study was conducted to examine the survival and persistence of Trichoderma and examine their effects on early stage germination of hot pepper seeds. Seeds were sown in sterile promix amended with three treatments, which included isolates from a commercial product RootShield® containing Trichoderma harzianum (T22), a Maryland Trichoderma isolate (GL13), and a control. Inoculation of the isolates were applied to the autoclaved promix via a cellulosic granular carrier Biodac® at a rate of 0.1 % (v/v). Seeds were sown into 96-celled trays and placed in a growth chamber for seven days at 27⁰C  and then placed in the greenhouse .  Days to emergence, germination  as well as seedling biomass were determined.  Microbial samples of the potting mix were analyzed for survival and persistence of Trichoderma strains periodically over 21 days post-inoculation. Strains GL13 and T22 showed increased germination percentage of 15.6% and 15.3%, respectively, when compared to the control. Days to seedling emergence above the soil line was significantly lower in GL13 when compared to the control. Microbial population of T22 and GL13 was 3.9 x 10⁵ CFU/g and 2.8 x 10⁵ CFU/g, respectively, after 14 days. Microbial population of T22 declined by 1.3 x 10⁵ CFU/g after 21 days, while GL13 increased by 2.0 x 10⁵ CFU/g.   GL13 increased root and shoot dry weight by 8.25% and 9.8%, respectively, over the control. Results show that Trichoderma may have a positive impact on hot pepper seeds at the early stages of germination and this may improve seedling quality and vigor.