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Washington State University Dairy News

July 2015 WSU Dairy Newsletter

Best to be Ready for an Early Corn Silage Harvest This Year

There is no question that this year has been warmer than normal for a majority of locations within the Pacific Northwest. As a result of the increased mean daily temperatures, we are also seeing a rapid increase in the amount of accumulated heat (growing degree day units – GDUs) required for corn maturation. It is only July, but it is time to be thinking about corn silage harvest. Since 2015 has proved to be one of the hottest years on record, temperatures from Snohomish, Lynden, and Sunnyside were assessed to determine the rate of GDU accumulation for 2015 compared to a “historical” period of 2008-2014.

We utilized data what we called historical data for the time period of 2008 to 20014, and compared that to data through July 9th of 2015. The data shown in figures 1, 2, and 3 show that the accumulative GDU by July 9 of this year was at 163%, 165%, and 157% of the 2008 to 2014 average for Snohomish, Lynden, and Sunnyside, respectively.

Corn silage should be harvested according to stage of maturity as judged by milk line development and moisture content of the plants. Getting out in the field early and monitoring the stage of maturity of corn silage will be important to ensure that harvesting is done at the correct time. Walk out in the field and look at a few ears to see what the maturity is now. Get your harvest equipment ready or be in touch with your custom harvester to make sure they are prepared for an earlier harvest.