Talking Turf

  • Jul14Fri

    A Most Fearsome Opponent: Taking control of Pythium

    July 14, 2017 Paul Giordano, Ph.D.
    When surveyed, most golf course superintendents will tell you that of all the diseases their turf may become afflicted with, the one that scares them most is Pythium. This is because overnight, Pythium blight can wreak havoc on high value turfgrass, devastating greens, tees and fairways with little to no warning signs or symptoms. With the recent deluge of rain in many parts of Eastern Canada, high humidity and climbing temperatures have resulted in isolated cases of Pythium blight, Pythium root rot, and seedling damping off on young turf areas.

    Pythium Blight / Seedling Damping Off

    Caused primarily by the pathogen Pythium aphanidermatum, this disease occurs on the turfgrass foliage and upper crowns when environmental conditions are hot and wet. Greyish, fluffy mycelia are often observed in morning dew when the disease is active, while mobile zoospores can spread via mechanical traffic and in standing water on turf surfaces. Pythium blight is favored by excessive nitrogen fertility and lush, succulent growth of turf during temperatures of 29-37 C, and is most prevalent when nighttime temps remain above 20 C. Newly established turfgrass seedlings are particularly susceptible to Pythium and a disease known as damping off. Young, germinating turfgrass should be protected preventively during periods of high temperatures and humidity for this reason.

    Pythium Root Rot

    Already diagnosed several on several putting greens this summer in Ontario due to heavy rains and saturated soils, this form of Pythium is caused by a number of different species, many of which are uncharacterized. Symptoms usually begin as irregular, yellow or orangish spots or patches of thin turf. No foliar mycelium is produced, but roots may appear water soaked and rotted with a significant reduction in mass or root hair production. Root rot can occur in cool or hot conditions, so long as there is excessive moisture and saturation of the soil for extended periods of time. Pythium root rot can occur fairly rapidly under these conditions, especially in low lying areas that are poorly drained.

    The Solution

    Banol has reliable preventive and curative activity on a multitude of different Pythium species. In fact, Banol is the only product specifically labeled for curative activity of Pythium blight, making it a unique tool to keep in your repertoire for when conditions get “scary”.

    For Pythium blight, applications need to be targeted on the foliage and crowns with typical spray applications when environmental conditions favor Pythium blight development. For Pythium root rot, Banol applications should be watered into the upper root zone to be most effective. Banol can be combined into programs with Signature Stressgard for a one, two punch against Pythium giving excellent preventative and curative control when needed most.