Anthracnose Alert!

The NC State Turf Diagnostics Lab has diagnosed several cases of anthracnose on creeping bentgrass and annual bluegrass putting greens in western North Carolina over the past couple of weeks. While we do diagnose this disease every year in that part of our state, this year seems to be slightly higher than normal. It appears the rain events following the mostly droughty spring/summer kicked this disease into full gear for the majority of locations. Also, keep in mind that this disease is not limited to western NC. We have diagnosed it in other regions, however the majority of the cases are from western NC.

Anthracnose stand symptoms on a golf course putting green.

Anthracnose stand symptoms on a golf course putting green.

Anthracnose stand symptoms on a golf course putting green.

Anthracnose stand symptoms on a golf course putting green.

Anthracnose symptoms are highly variable, appearing yellow to orange in color and in an irregular pattern, in small freckle-like spots, or in circular patches up to 1’ in diameter. Symptoms are typically most severe in areas that are stressed from low mowing, excessive traffic, or inadequate irrigation or fertilization. On individual plants, symptoms first appear on the oldest leaves, which die back from the tip, and gradually progress to the younger leaves.

anthracnose-signs-acervuli-lbc

Anthracnose acervuli as would be seen using a hand lens

Anthracnose can be diagnosed in the field with a good hand lens. So far, all of the cases we have diagnosed have been foliar infections. Fortunately, foliar anthracnose tends to be easier to manage versus basal forms that severely damage leaf sheaths, crowns, and stolons.

anthracnose spores

Anthracnose spores under a microscope (400x)

For more information about anthracnose, including control recommendations, click here.