Snow on the old 9th green - circa 1970
A Happy New Year to all
The hottest December in five years, combined with the second driest December in ten years has meant a lot of hand watering over the last month. The reason for this is that the grass species that we have here on our greens are a blend of Creeping bentgrass and Poa annua, which are cool-season grasses found on golf greens throughout the world. Optimally, these grasses maintain their maximum growth rate at temperatures ranging from 15 – 24°C for shoots and 10 – 18°C for roots. Turf quality of Creeping bentgrass and Poa annua can, and often does decrease when temperatures exceed the optimal levels for extended periods of time. Growth inhibition, and even death, can occur at extreme temperatures. From data collated by myself and from a local weather station, it is known that both air and soil temperatures often exceed these optimal ranges for prolonged periods during the hotter months of the year in our particular location.
The water management practices in place here at Blackwood are designed to keep our surface air temperature and soil temperature as close to the optimal ranges as possible. Water usage is closely managed to meet the moisture needs of the grass, but not to exclude oxygen from the soil. Irrigation schedules and rates are based on evapotranspiration rates and the water holding capacity of the soil. Frequent syringing and hand watering also serve to moderate the surface temperature during heat stress periods.
With the heat of summer now here, when the forecast temperature for Adelaide is for 38°C and above, there may be a need to run a 3-5 minute syringe cycle on the greens and surrounds during the late afternoon, the purpose of this is to reduce the evapotranspiration rate of the turf by lowering the temperature and increasing the atmospheric water vapour content surrounding the leaves during these potentially damaging heat stress periods.
13th green - Another temper divot - 28/12/11
