Effects of Early Spring and Preventative Snow Mold Fungicide Applications on DMI Sensitive and Insensitive Populations of Sclerotinia Homoeocarpa

Seaman, Marvin D

Publication:
Effects of Early Spring and Preventative Snow Mold Fungicide Applications on DMI Sensitive and Insensitive Populations of Sclerotinia Homoeocarpa

dc.contributor.advisor	Geunhwa Jung
dc.contributor.advisor	Prasanta Bhowmik
dc.contributor.advisor	Patricia Vittum
dc.contributor.author	Seaman, Marvin D
dc.contributor.department	University of Massachusetts Amherst
dc.contributor.department	Plant & Soil Sciences
dc.date	2024-03-28T20:42:01.000
dc.date.accessioned	2024-04-26T18:15:23Z
dc.date.available	2024-04-26T18:15:23Z
dc.date.submitted	February
dc.date.submitted	2014
dc.description.abstract	Dollar spot, caused by the pathogen S. homoeocarpa (F.T. Bennett), is a common disease that infects a wide variety of turfgrasses all over the world. Yet it is significant problem on golf course putting greens and fairways consisting of creeping bentgrass (Agrostis stolonifera L.) and annual bluegrass (Poa annua L.). It is active in a wide variety of environmental conditions ranging from 16-30˚C but favors warm, humid days, followed by cool nights. Sclerotinia homoeocarpa overwinters as dormant mycelium in dead plant tissue. In the spring, germinating mycelia begin to infect leaf blades causing foliar lesions, which then spread via mycelium by means of wind, rain, animals and equipment. While there are a number of cultural practices that can reduce disease severity, frequent fungicide applications are required to maintain acceptable playing conditions on a golf course. The repeated use of fungicides with the same mode of action has led to the development of fungicide resistance of S. homoeocarpa to certain fungicide classes. Most notably, demethylase inhibitor (DMI) fungicides have been found to have varying levels of inefficacy against S. homoeocarpa across North America. The cause for reduced efficacy is suspected to the shifted sensitivity levels of many S. homoeocarpa populations, which are resulted from repeated use of the DMI fungicide. Recently, “early-spring fungicide applications” targeting to reduce initial inoculum density of dollar spot have gained popularity in an attempt to reduce dollar spot severity. In addition, preventative fungicide applications (from late October through mid-November) containing DMI fungicides have been traditionally practiced to target snow molds (caused by Microdochium nivale, Typhula spp.) in the northeastern United States. To date, there is not a clear understanding as to what effect, if any, these applications have on S. homoeocarpa DMI sensitivity or residual dollar spot control the following year. Traditional preventative snow mold applications were also investigated on the effect of S. homoeocarpa DMI sensitivity and early-season dollar spot control. The objective of this study was to investigate the effect of early-spring dollar spot application and late-fall snow mold application on S. homoeocarpa population with a bimodal distribution of DMI sensitive and insensitive isolates.
dc.description.degree	Master of Science (M.S.)
dc.identifier.doi	https://doi.org/10.7275/6470334
dc.identifier.orcid	N/A
dc.identifier.uri	https://hdl.handle.net/20.500.14394/33155
dc.relation.url	https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1183&context=masters_theses_2&unstamped=1
dc.source.status	published
dc.subject	dollar spot
dc.subject	snow mold
dc.subject	early spring
dc.subject	Agriculture
dc.title	Effects of Early Spring and Preventative Snow Mold Fungicide Applications on DMI Sensitive and Insensitive Populations of Sclerotinia Homoeocarpa
dc.type	openaccess
dc.type	article
dc.type	thesis
digcom.contributor.author	isAuthorOfPublication\|email:montanamarv1@hotmail.com\|institution:University of Massachusetts Amherst\|Seaman, Marvin D
digcom.identifier	masters_theses_2/170
digcom.identifier.contextkey	6470334
digcom.identifier.submissionpath	masters_theses_2/170
dspace.entity.type	Publication