Netting and Chemicals Can Help Fight Sunburn in Apples

Sunburn is a constant concern of apple growers in Central and Eastern Washington due to the large volume of sun the area receives on an annual basis.

WSU’s Dr. Lee Kalcsits spoke at Apple Day in Wenatchee last week and, even with an old figure, the damage is staggering.

“The average annual losses for Washington State is about $100 million, this was in 2003. There’s been some more higher value cultivars that have come along since then so I think that dollar value impact is a little bit more even though we have maybe a slightly better control of sunburn.”

Sunburn can make apples susceptible to pathogens, and lead to a downgrade for the crop, or a culling.

There are many ways to handle sunburn, sprinklers, chemicals, but Kalcsits said the best method, if a grower can afford it, is to cover the trees with netting.

“The netting doesn’t reduce the air temperature but it reduces the incoming light by 20 percent and it reduces the total amount of radiation coming in by 20 percent.”

That means lower soil temperatures, better soil moisture and more return bloom. Kalcsits was quick to point out that netting, while the best, isn’t the only successful method and growers, if properly planned, can fight sunburn using many different tools.

If you have a story idea for the Washington Ag Network, call (509) 547-1618, or e-mail krounce@cherrycreekradio.com.