Research done at North Dakota State University and the University of Minnesota showed that a wide range of plant population resulted in high recoverable sucrose, but plant populations of 175 to 200 plants per 100 foot of 22 inch wide rows consistently resulted in the maximum recoverable sucrose per acre. It is important that the plants be evenly spaced within the rows.
Lower plant populations (less than 100 plants /100 ft of row) take longer for the canopy to cover the soil resulting in emergence of weeds later in the season. In conventional sugarbeet, weed control becomes more difficult and costly with lower population. However, weed control is not a problem for most growers using glyphosate tolerant sugarbeet, even when populations are reduced, say by insects, diseases or wind.
Will later planting date influence plant population?
Later planting does not have an impact on plant population; as a matter of fact, growers should do their best to ensure 175 to 200 plants per 100 foot of row. Why? Later planting will mean a shortened growing season and since most fields are fertilized, you need a good population to utilize the available nitrogen. Lower populations may result in larger beets but with lower sucrose concentration which will result in higher processing costs and less profit for growers.
Can you still get high yields at a later planting date?
You can still have good yields when planting in May; in 2009, research trials planted on May 25 at Prosper, N.D., had average yields of 30 tons per acre! Wet field conditions in 2013 resulted in many growers planting their sugarbeet crop in May. Although there was inadequate rainfall in the summer, rains in September facilitated a high yielding, albeit relatively low sugar quality crop in 2013.
What happens at later planting dates?
Planting sugarbeet late typically means that planting will be into warmer soils. Seedling emergence takes place faster in warmer soils with adequate moisture and oxygen compared to colder soils. For example, emergence will take about 21 days when planting into soil with a temperature in the low 40s°F; however, emergence will be much faster – in 5 to 7 days - when planting into soil with a temperature of 60 to 70°F. Faster emergence and good growth will lead to a favorable sugarbeet crop. However, a warm soil is not only favorable for fast sugarbeet emergence, but also favorable for infection and disease development. Necessary precautions such as using fungicide seed treatments and in-furrow fungicide applications should be taken to reduce the possibility of diseases such as damping-off.