Potassium Nutrition Affects Anthracnose on Annual Bluegrass

Abstract

Core Ideas This study provides evidence that K deficiency can increase anthracnose severity of annual bluegrass turf. Deficiency can be identified with testing of mat layer and tissue K concentrations. Potassium values less than 43 mg kg−1 in the mat layer (Mehlich 3 extractant) and 20 g kg−1 in leaf tissue will increase anthracnose severity of annual bluegrass. Potassium fertilization can improve stress tolerances in turfgrass; however, its effect on turfgrass diseases is inconsistent and not well understood. A 3‐yr field study was initiated to determine the effect of K fertilization rate and K source on anthracnose disease of annual bluegrass turf. Potassium chloride and K2SO4 were applied at K rates of 54, 109, and 218 kg ha−1 yr−1 as a 2 × 3 factorially arranged randomized complete block design with four replications. Potassium nitrate and K2CO3 were also included at the 218 kg K ha−1 yr−1 rate, as well as an untreated check. Nonlinear regression models were used to estimate critical concentrations of K in the mat layer and tissue with respect to anthracnose severity. All K treatments reduced disease severity compared to the untreated check (no K); however, KCl was less effective than the other sources when applied at the 218 kg K ha−1 yr−1 rate. The Cate–Nelson regression model predicted that K values less than 43 mg kg−1 in the mat layer (Mehlich 3 extractant) and 20 g kg−1 in leaf tissue will increase anthracnose severity of annual bluegrass (ABG). This study provides evidence that K fertilization can reduce anthracnose severity and that the severity of this disease can be correlated with mat and tissue K concentrations. Thus, it is important to monitor K in ABG turf and to maintain sufficient levels to reduce disease severity and improve turfgrass quality.

Effects of Potassium Fertilizer Application on Festuca arundinacea I: Plant Growth and Potassium Requirement

“…Potassium, as one of technically macronutrients, is often deficient in soils on which turf is grown, and has received the greatest attention in the development of a fertility program for turf (Christians et al 2016). Previous studies have shown that the application of K fertilizer can promote the growth of turfgrass and enhance its adaptability to adversity (Wu et al 2019;Schmid et al 2018), which is beneficial to promote the turf cover and turf quality, prolong the lawn green period, and improve the ecological environment (Ihtisham et al 2018). Recent studies have shown that the effect of applying K fertilizer on the growth of turfgrass is closely related to the K level of the soil (Ihtisham et al 2020;Dokbua et al 2021).…”

Susceptibility of Chewings Fescue and Hard Fescue to Anthracnose Disease Caused by Colletotrichum cereale

“…); although, it is typically not considered a major disease on these hosts (Bonos et al 2006). The disease is most severe when environmental conditions or management practices induce plant stress (Hempfling et al 2017;Inguagiato et al 2008Inguagiato et al , 2009Roberts et al 2011;Schmid et al 2018;Wang et al 2018).…”