ISSUE 10 July 5, 2001
CAUSE OF POOR SUGARBEET GROWTH STILL ELUSIVE
There are areas in the Valley in which most crops appear to thrive, but sugarbeet growth is very poor. These areas of "weird beets" are generally found on lighter colored, coarser textured soils. Transects in a study last year suggested that magnesium deficiency was the likely problem. Often the sites are low in pH, but not always. As magnesium is preferentially leached from soils with high calcium content, it seems reasonable that magnesium deficiency was just as possible in high pH, sandy soils as in low pH soils. So far, our studies this spring have neither supported nor discredited this theory. Our plots, like many fields, have been the victim of root rot, wet, compacted soils, and even dry weather after seeding, resulting in poor stands at one site. So it has not been possible to pin point a strong response at any site to date. Work is progressing, but the cause and cure may take longer than anticipated.
The weird beet areas all seem to have the following characteristics-
1. Coarser and lower organic matter soils, often with a history of wind erosion.
2. Higher in landscape position.
3. Some kind of discontinuity at depth, suggesting lateral water movement away from the area.
4. Low pH is common, but high pH, with lower Mg relative to Ca content is also found.
5. At the 6th leaf stage, the beets are only a few inches tall, often with a purple leaf margin, but not always.
6. Beets in affected areas seem to improve as the season progresses, but do not reach the tonnage of unaffected areas.
If one of these areas is found, taking plant and soil samples from affected and unaffected areas may help to isolate a nutritional cause. But this year is not as simple as last year was, and I am concerned that other confounding growth inhibitors, such as root rots, may muddy up the results we see.
NDSU Extension Soil Specialist