Evaluating biological thatch control in turfgrass

Abstract

AbstractThatch is a layer of living and dead plant material between turfgrass leaf tissue and soil surface; it can decrease playability, increase scalping and disease pressure, reduce pesticide efficacy and water infiltration, plus harbor insects. In golf putting greens, disruptive mechanical practices such as vertical mowing, core cultivation, grooming, and topdressing are traditionally used for managing thatch; however, several biological products have been marketed as non‐disruptive thatch reducers. Greenhouse experiments were conducted to evaluate thatch reduction and rooting depth of two commercial humic acid based biostimulant products, Worm Power (WP) and EarthMAX (EM). Products were applied at labelled rates and timings. EM was applied at two rates, indicated as EM (1) and EM (2). Two industry standards were also included: blackstrap molasses and sand topdressing. For both years, blackstrap molasses, EM (1), and EM (2) reduced thatch thickness compared to untreated by 30, 24, and 18% respectively. However, no decrease in thatch weight by treatment was observed. In Year 1, EM (1), and sand topdressing provided an average of 16% greater root length than untreated. However, in Year 2, WP provided 16% greater root length than untreated. EM (1) provided 117% greater root mass than untreated control in Year 2. No treatment provided greater root mass in Year 1. Thatch depth reduction indicate these products may be beneficial, but, inconsistent results mean further research is required.