Sun and Heat Damage to Turf
Posted on May 3, 2012
Overexposure to the sun’s rays damages turf in two general ways. Excessive infrared exposure leads to heat stress, which causes plants to respond by shutting down the photosynthetic process. UV rays are responsible for another type of damage (sunburn, DNA damage, and physical damage to leaf surfaces) that inhibit the photosynthesis and transpiration processes. While these sun-related stresses are different, they both result from excessive exposure to ultraviolet and infrared light from the sun and can be equally devastating to turf quality.
Sunlight reaching your golf course’s turf is composed of:
- 4% ultraviolet (UV) light: extremely damaging to turf and skin
- 52% infrared (IR) or weaker light: directly responsible for generating heat
- 44% visible light: directly responsible for photosynthetic activity (PAR)
The primary mechanisms responsible for deteriorating turf quality from prolonged bouts of severe hot weather are:
- Ultraviolet radiation damaging cellular DNA and the epicuticular waxes on the leaf-surface
- Infrared radiation is responsible for secondary epidermal damage and over-heating of the plant and resultant damage
- Infection by secondary bacterial and fungal diseases is common in heat stressed and sunburned turf
UV rays are responsible for another type of damage (sunburn, DNA damage, and physical damage to leaf surfaces) that inhibit the photosynthesis and transpiration processes.
Turf experiencing heat stress is more vulnerable to damage from other summer related stresses (e.g.; excessively close mowing, traffic and wear, warm weather fungal diseases, poor water quality, poor soil drainage, poor air movement, insect damage etc.). In other words, during a period of mid-summer heat stress the grass plants are more vulnerable to everything that can cause damage.
Future blog entries will discuss the mechanisms of UV and IR damage to turfgrass. We will also present independent testing results that verify that Turf Screen’s key ingredients possess a high refractive index with strong UV light absorbing capabilities. AND, they are also highly reflective of thermal IR; by reflecting IR light the turfgrass stays cooler, reducing heat damage.