Sugarbeet replanting considerations
Determining whether to replant sugarbeets depends on multiple factors including existing plant population, time of year, and reason for poor establishment.
In Michigan, it is typical that between 5 to 10 percent of the sugarbeet crop may get replanted. Establishment of a good sugarbeet stand is extremely important in setting the foundation for high quality and high yielding sugarbeets. Producers hope to establish an optimum population of about 200 sugarbeets per 100 foot of row. However, sugarbeets are known for their ability to compensate for thin stands. In one Sugarbeet Advancement variety trial in 2011, a variety with a population of only 104 sugarbeets per 100 foot of row yielded over 30 tons per acre. Plant population is important, but is only one of many factors that should be considered. Each field should be analyzed on an individual basis.
Try to determine what caused a field to establish a poor population. For emergence issues that are caused by seedling disease or insect activity, growers will want to try to remedy the situation by applying appropriate insecticide, in furrow fungicide or seed treatment when replanting. Quadris applied in a T-band will control seedling Rhizoctonia and Pythium. Tachigaron seed treatment is effective on Aphanomyces.
Heavy rainfall after planting often causes soil crusting or can cause the seed to “sink” when planted into a fluffy seedbed, which puts the seed too deep for good emergence. If replanting is warranted, sometimes the best approach maybe without working the field. This allows you to plant into a firm seedbed with moisture and retain those plants that are already established.
When trying to determine the average plant populations, mark out two, 50-foot rows side by side. Each set of rows will give you what is established in 100 feet. Make these counts in at least 10 locations in the field. While counting, make note if the stand is evenly thin or has a lot of large gaps. It is also important that the established seedlings are healthy. Seedlings that are sickly, yellow or hanging on by a thread generally have root issues and will continue to die off. Sugarbeet stands that are evenly thin generally compensate better than those fields that have large gaps with no beets. Narrow row beets will generally have the advantage over wide row beets in thin populations.
Prior to glyphosate-tolerant sugarbeets, thin stands were often replanted because weed control with traditional chemicals was very difficult. We can now effectively control weeds all season. When considering replanting sugarbeets, growers should consult with their local agriculturist and utilize any other expertise that is available. Thin but healthy stands should be kept. If late in the season and you are considering working the soil before replanting, there is no guarantee that the replants will be successful.
Replanting is a difficult judgment call based on health of plants, evenness of gaps, and time of year. There is no hard rule on how many beets should be kept, but there have been excellent yielding fields that had as few as 60 to 80 healthy beets per 100 foot of row.