blueberry scorch or shock

Asked August 14, 2013, 2:51 PM EDT

hello, i'm a home gardener in portland with 3 blueberry bushes (berkley, earliblue, blueray) that have either scorch or shock. they had it last year too and haven't produced any berries the past 2 years. i've read that commercial growers are supposed to get their bushes tested and destroy bushes with scorch - but haven't found info for the home gardener. advice? destroy? test? treat? Is it safe to plant new bushes in the same location?

Multnomah County Oregon blueberries horticulture

1 Response

Hello,

Based on the attached photo, the plant is not showing symptoms of either virus. Instead the symptoms are related to salt and water stress (they often go hand in hand). While it is impossible to correctly diagnose a problem with a photo alone, I would suggest evaluating your fertilizer and irrigation program. Please see the home garden publication on growing blueberries (http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/12202/ec1304.pdf;jsessionid=FD49AEE8D8...) for fertilizer and irrigation recommendations. Fertilizing with the incorrect product (blueberries only take up the ammonium form of nitrogen and fertilizing with the more common products that contain nitrate nitrogen is like adding salt to the plant making it difficult for the plant to take up water). Also, blueberries require about 2 inches of water a week in this kind of weather. Check the soil moisture to make sure irrigation is adequate over the root zone area. Water and/or salt stress will reduce growth and fruiting. Finally, these stress plants will require heavy pruning to encourage more growth next year (while fixing any issues with fertilization or irrigation). Please refer to the pruning DVD available from the OSU Extension Service for pruning recommendations for weak plants. (http://extension.oregonstate.edu/catalog/abstract.php?seriesno=DVD+2)