While the last couple of summers have been mild, the long term forecast is for warmer and drier seasons. Astute growers are recognizing the need to protect crops against sunburn and heat stress.
Estimates of crop loss from sunburn and heat stress vary, however, claims of up to 40% damage are often quoted.
As pressure on grower margins increases, it is more important than ever to harvest the highest possible percentage of quality fruit from every hectare or megalitre of water. Improving pack-out percentages is one of the most effective ways to improve farm profitability.
Sunburn damage
Sunburn damage on fruit crops is caused by an interaction of ultraviolet (UV) and infrared radiation (IR) reaching fruit surfaces.
Therefore, products which most effectively prevent UV and IR light from reaching fruit surfaces will most efficiently protect them from sunburn.
Independent laboratory comparisons
Side by side laboratory tests, commissioned by NovaSource, compared products claiming sunburn protection, and proved that the level of protection against UVa, UVb and Near Infrared Radiation (NIR) varies greatly.
The independent laboratory measured film depositions at a range of application rates up to the label maximum, to determine how much UVa, UVb and NIR was reflected away or passed through to the surface below.
Included among the five products tested were three formulations of products claiming sunburn protection in Australia.
Graphs 1, 2 and 3 show that Surround outperformed tested competitors against UVa, UVb and NIR. The Surround treatment had a higher percentage of sprayed material adhered to the substrate, with the Surround formulation providing a more effective barrier than the competitor products.
Proven track record
These results help to explain why Surround has a proven track record of providing consistent protection against sunburn in Australia.
For more information contact Darren Thomas
phone 0405 964 623 e-mail
To see all the graphs, see the November 2012 Tree Fruit
