Fortification of Potassium Silicate with Compost Tea and Seaweed Extract for the Management of Dollar Spot (S. homoeocarpa) of Turfgrass

Abstract

The effect of potassium silicate fortified with cow manure compost tea and seaweed extract on dollar spot (Sclerotinia homoeocarpa) was studied in creeping bentgrass (Agrostis stolonifera L.) and perennial ryegrass (Lolium perene L.). Application of potassium silicate fortified compost tea increased the silicon content in bentgrass and ryegrass at 5 days after treatment, but there was only a minimal effect on silicon content in the grass at 15 days after treatment. However, the fortified treatments did not affect the susceptibility of grass to dollar spot disease in the greenhouse experiments. Fortified treatments did not have a significant effect on the chlorophyll content, total phenol content and phenylalanine ammonia lyase activity in creeping bentgrass. Similarly, the treatment did not affect area of the lesion and mycelial growth of the fungus. Although the synergistic effect of silica fortification was not investigated in detail, preliminary results of the study indicate potassium silicate fortified with compost tea or seaweed extract was not different from that of non-fortified treatments in reducing dollar spot disease in the greenhouse trial.