Use of Mushroom Compost to Suppress Artillery Fungi

Abstract

Mushroom compost (spent mushroom substrate, SMS, mushroom soil) exhibits suppressive characteristics against various fungi, as well as against plant diseases caused by fungi. In addition, mushroom compost has physical and chemical characteristics that make it ideal for blending with landscape mulch to enhance growth of horticultural plants. There is currently an oversupply of used compost in mushroom-growing areas, where it represents a major disposal and regulatory problem. Concurrently, artillery fungi (Sphaerobolus spp.), which commonly live in landscape mulch, have recently become a plague for many homeowners due to the sticky spore masses they expel onto houses and cars. There is increasing interest among homeowners to control artillery fungi without the use of chemical fungicides. Therefore, we have explored the use of aged mushroom compost as a biocontrol agent for artillery fungi. The abundance of mushroom compost, as well as its antagonistic nature to fungi, made it an ideal candidate to blend with landscape mulch to suppress artillery fungi without the use of fungicides. We previously reported that 100% aged mushroom compost suppressed artillery fungi. In the current 3-year field study, we examined the suppressive nature of lower percentages of aged mushroom compost blended with wood landscape mulch. Lower percentages of compost did suppress artillery fungi, but the high variability in the data precluded detailed statistical analyses. Nevertheless, blending mushroom compost with landscape mulch may yield a possible solution for both the compost disposal and the artillery fungi problems.