Cool Season Brown Patch December 11, 2012 By Pat Gross

(L) Cool season brown patch on kikuyugrass is very active during cool, wet, overcast conditions. (R) The orange color along the edge of the ring is a distinguishing characteristic of the disease.

The recent rain and cooler temperatures throughout southern California have provided the perfect environment for cool season brown patch. Disease activity has been most noticeable on kikuyugrass fairways and roughs in recent weeks. Bermudagrass and seashore paspalum also are susceptible hosts.

The disease is favored by the following conditions:

  • Average air temperatures greater than 60°F
  • Wet, overcast conditions
  • High nitrogen fertility

There are several fungicides that can be used to treat the cool season brown patch if symptoms are severe, including:

  • chlorothalonil
  • thiophanate-methyl
  • azoxystrobin
  • pyraclostrobin
  • trifloxystrobin
  • flutolanil
  • iprodione

Applications of fungicides and any pest control material should always be done according to manufacturers label directions. Some superintendents prefer to spot treat infected areas as symptoms become visible while other courses with a history of severe disease activity treat preventively.

Source: Pat Gross