A Summer BrawlSEPTEMBER 2, 2016By Jim Skorulski, agronomist, Northeast Region
Roberto Duran's famous phrase "No mas" that ended his brawl with Sugar Ray Leonard, and essentially his career, comes to mind this summer. Enough is enough already! Whether dealing with season-long drought or the effects of heat and humidity, this season has pushed turf and many turf managers to their limits. Courses in the northern half of the region continue to hope for rain while those in southern half wish the rain would stop for a while.
Drought conditions in parts of the Northeast have not improved and in some areas have worsened. As a result, golf facilities have had to reduce or eliminate irrigation to fairways and nonessential areas. The drought has drained water from irrigation ponds and energy from maintenance staffs, which have been busy with hoses far too long to remember. Courses that have significantly reduced, or eliminated, fairway irrigation are anticipating some turf injury, especially where cart traffic is heavy. The extent of drought-related injury is difficult to determine until we begin to see some regrowth. However, we know there will be overseeding ahead once the drought breaks and there is enough water available to initiate that work. Weed encroachment has been extremely high in areas that have experienced both drought and rain events. Drought thins the turf and then rains promote weed germination and growth.
Heat and Humidity
High temperatures combined with rain and humidity has taken its toll on putting greens in the region. Cool-season turfgrass can tolerate heat but is pushed to its limit by persistently high temperatures. Higher soil and air temperatures increase plant respiration rates, drawing more energy than plants can produce. Plants’ energy reserves are depleted; the gas tank is empty. Weakened plants are vulnerable to temperature extremes, physical damage and disease. We have seen weakened annual bluegrass plants fail on greens located in difficult growing environments or in areas with poor drainage. Wet wilt, heat stress and physical damage have caused the greatest injury. Many turf pathogens are still active too. Creeping bentgrass has been holding its own, but it too has been damaged in very hot environments.
About the only grasses thriving in this heat are crabgrass, goosegrass, nutsedge and kyllinga. These weeds are well suited for this type of weather and are taking full advantage of the ideal growing conditions and weakened cool-season turf. Pre-emergent herbicide programs that usually provide season-long control of annual grasses are breaking down early with the elevated soil temperatures.
The annual bluegrass weevil has also decided to join the party after being conspicuously absent for most of the spring and early summer. Reports of more extensive feeding damage have been observed this month. It is just one of those years!
The calendar tells us that things should be getting easier with shorter days and cooler nights ahead. That would be ideal for badly-needed aeration and overseeding programs. Let's hope the stubborn pattern of hot weather breaks soon. Until it does, maintain a conservative management approach, especially if turf is very weak. As valuable and necessary as aeration may be, at this time proceed with caution. As they say, it is sometimes best to live to fight another day.