yellow patch

plural yellow patches

1. uncountablebiologyA disease affecting several varieties of grasses, including bentgrasses, annual bluegrass, some perennial ryegrass and Kentucky bluegrass, which results in the development of yellow or brown rings.

   Yellow patch, sometimes called cool-temperature brown patch, develops during prolonged cool (50-65°F; 10-18°C), overcast, and moist periods from late autumn to early spring.

   2013, Thomas L. Watschke, Peter H. Dernoeden, David J. Shetlar, Managing Turfgrass Pests, →ISBN, page 97

   1 more example

   Throughout the year pathologists receive numerous samples of yellow, creeping bentgrass or annual bluegrass (Poa annua) from putting greens. In autumn or spring, superintendents sometimes suspect that yellow tuft (Sclerophthora macrospora) or yellow patch (Rhizoctonia cerealis) diseases are the problem.

   2002, Peter H. Dernoeden, Creeping Bentgrass Management: Summer Stresses, Weeds and Selected Maladies, Hoboken, New Jersey: John Wiley & Sons, Inc., →ISBN, page 25

2. countablehistoricaluncountableA yellow badge.