As you scout for insects and disease in your hopyards this spring, undoubtedly dodging puddles, you are likely finding fewer critters than usual. The cool, wet weather that we have been experiencing lately has taken its toll on the insects that are typical for this time of year. However, downy mildew is one problem that most of us are dealing with as a result of these conditions. For comprehensive information about downy mildew, disease symptoms and management in hops, check out the following factsheet: http://www.uvm.edu/extension/cropsoil/wp-content/uploads/DownyMildew.pdf
If you would like to confirm whether or not downy mildew has infected your hop plants, you can submit a sample to your local University Extension Plant Diagnostic Laboratory. Visit their website or call for specifications on how to prepare and submit a sample. A diagnosis will cost between $15 and $30, depending on the lab. Contact your local Plant Diagnostic Lab by following the links below or contacting your local Extension office:
Cornell University Plant Disease Diagnostic Clinic
334 Plant Science Building
Ithaca, NY 14853
101 University Drive, Suite A7
Amherst, MA 01002
University of Vermont Plant Diagnostic Clinic
201 Jeffords Building
63 Carrigan Drive
University of Vermont
Burlington, VT 05405
Other pests that can really take advantage of the cool, wet weather are snails and slugs. These slimy pests are generalist feeders, and during prolonged periods of spring rains, can do damage to just about any crop. They are not generally a serious problem, but if they are, they can be easily managed with iron phosphate-based products.
Despite the slow start, insect and mite populations in hopyards are on the rise. The first generation of potato leafhoppers have made their perennial journey up from the south and have begun to lay their eggs throughout the region. We have also begun to find pockets of hop aphids and two-spotted spider mites. The good news is that along with these problematic species, we have also been finding plenty of beneficial insects that can lend a hand in managing the pests. We have been finding spider mite destroyers, plenty of their ladybug cousins, and the distinctively stalked lacewing eggs and crowned predacious stink bug eggs foreshadow good news to come.
For more information about the organisms discussed above, and plenty more, please check out our hops program website: http://www.uvm.edu/extension/cropsoil/hops
And of course, keep calm and hop on…