It has been another mild winter in the potato-production regions of Washington state.
Temperatures hit a winter low of 17 degrees this morning in Moses Lake. Despite hopes the eastern Washington area would receive a normal winter with freezing temperatures, the area has been missed by Arctic air.
The 17-degree F mark will not be cold enough to freeze potatoes left in the soil of fields after harvest last fall. This will lead to another round of volunteer plants next spring and summer.
Washington growers have been very concerned about these over-wintering tubers and their growth cycle because they are many times carriers of plant diseases. They are also susceptible to viruses vectored by insects, which are then spread to nearby potato fields. Even though fields are rotated, if they emerge in corn, grain or other crops, they are very difficult to kill.
For this reason, the Washington State Potato Commission and the National Potato Council have been petitioning the EPA for chemicals that can be used to control them. If these crop-protection products are used correctly, they can be very effective in ridding rotational crops of volunteer plants.