Tops on preferred to tops off when it comes to sugarbeet freeze protection
When freezing temperatures threaten at sugarbeet harvest time, be sure sugarbeet canopies are left intact and not defoliated.
In 2013, thousands of tons of sugarbeets have been reportedly abandoned in the western United States due to very low temperatures and multiple freezing events. Both frozen and freeze-injured sugarbeets that are put into long-term storage piles will not store properly. Even a small quantity of frozen or freeze-injured sugarbeets put into a pile can cause a hot spot of deterioration to develop and jeopardize surrounding sugarbeets. We are now into the November harvest and the chances of sub-freezing temperatures are increasing.
Michigan is very fortunate that the Great Lakes help moderate our fall temperatures. This allows us to extend our harvest season significantly longer than many other continental growing regions. However, we are not immune from freeze events and growers need to be aware when those are predicted. Foliage of the sugarbeets can help protect the beet crown from freezing. Michigan Sugar Company and Michigan State University Extension observations confirm that heavy foliage will help keep the sugarbeets insulated and reduce freeze injury. Do not leave defoliated unharvest sugarbeets during a frost or freeze event.
Be aware that every frost or freeze event varies in temperature and duration. The impact of the event can also depend on elevation and proximity to the Great Lakes. When an event occurs, it may take ag staff some time to evaluate the impact and overall occurrence. If crowns are frozen, they will appear yellowish or translucent when cut with a sugarbeet knife. Depending on the intensity of the frost or freeze, harvest will be delayed generally from a few hours up to three days when injury is more severe. Longer delays can allow sugarbeets to “heal.” On projected frost or freeze nights, make sure that defoliation is not done too far ahead of harvest. Should a breakdown occur that does not allow topped sugarbeets to be harvested, contact your agriculturalist for the handling procedure.