ISSUE #409

409 - Close The "Gap" In 2002!


What Is The "Gap"?

It's the difference between the yields shareholders achieve and the potential yields that were possible. Narrowing this gap by 5, 10 or 20 percent will enhance ON-FARM profits often without increased production costs. Sugarbeet yield potential is about 30T/A. Sugar content has frequently reached 20% in some fields. Shareholders need to plan to control every factor influencing yield to the greatest extent possible, to narrow the gap on their farms under the environment they produce the crop in 2002.

Controllable Production Factors in the Fall

  • Seedbed preparation/land forming
  • Field selection/crop rotations
  • Soil testing/fertilizer application
  • Variety selection
  • Seed treatment selection
  • Harvesting practices

Field Selection and Crop Rotations

Table 1 shows the impact of previous crop on sugarbeet yield and quality from American Crystal Sugar Company grower practice records, 1998-2000.

Previous CropYield T/ANet Sucrose (%)Sugar/T (lbs.)Sugar/A (lbs.)Revenue/T ($)Revenue/A ($)
Edible Beans 22.0 16.24 325 7150 35.20 775
Potato 22.6 15.93 319 7209 33.74 761
Barley 20.8 16.30 326 6781 36.48 757
Fallow 21.2 16.46 329 6975 35.24 748
Wheat 21.5 16.21 324 6966 34.71 746
Corn 20.8 16.08 322 6698 35.26 735
Soybeans 20.2 16.01 320 6464 33.93 685

Shareholders should avoid beets after soybeans whenever possible, reduce nitrogen use with potatoes in rotation, use 4 year rotations or longer whenever possible.

Variety and Seed Treatment Selections

Q. How severe was aphanomyces seedling and root rot in 2001? 

A. Aphanomyces root rot has caused major losses for growers especially in the Moorhead and Hillsboro factory districts for several years. This problem is getting more severe in Crookston, East Grand Forks and Drayton as well. In May and early June of 2001 seedling losses due to aphanomyces damping off caused severe stand loss in numerous fields throughout the Red River Valley. Plant populations were reduced well below recommended levels and loss of yield and quality resulted.

Q. What factors favor aphanomyces development and disease severity?

A. warm soil (68-860F), wet soil - especially water logging, innoculum buildup from previous disease in a given field, innoculum survives 10-20 plus years in soil, poor weed control, alternate hosts are pigweed, lambsquarters and kochia

Q. Do seed treatments help control aphanomyces?

A. Yes - seed should be treated with Apron-Thiram and definitely with Tachigaren where aphanomyces is present.

Q. How long will seed treatments be effective?

A. They give early season damping - off protection for 3-4 weeks.

Q. Can root rot overwhelm a seed treatment under certain conditions?

A. Yes - even on a partially resistant variety with heavy rainfall, flooding and prolonged soil saturation.

Q. Can root rot be detected early enough to replant a field?

A. Yes - if plant populations from an early planting fall below 50 or 60 beets/100' of row a field should be replanted. Tachigaren seed treatment should be used if it is available. ACSC requires replanting of fields until June 1.

Q. Does variety make a difference?

A. Yes - aphanomyces specialty varieties have been greatly improved in recent years and will yield very nearly as well as the best non-resistant varieties.

Q. What rotational crops reduce root rot?

A. There is no evidence that previous crops affect aphanomyces incidence and severity. Control broadleaf weeds and avoid short rotations. Some research indicates an oat precrop may reduce disease levels.

Q. Does cultivation help reduce aphanomyces root rot?

A. It helps dry out and aerate the soil. It may help dilute innoculum but likely is not effective in reducing disease.

Q. What should a grower do to reduce likelihood of economic losses due to aphanomyces?

A. Recommended pratices of greatest benefit are use of tolerant varieties and use of Tachigaren seed treatment.

Q. When should a grower use tolerant varieties and Tachigaren seed treatment?

A. Growers should strongly consider use of Tachigaren and tolerant varieties, anytime a field will be planted to beets that has had serious stand loss and yield and quality reductions in the past.

Q. Do certain herbicides increase aphanomyces?

A. No increase in aphanomyces has been found due to use of preplant, pre-emerge, or post applied herbicides.

Q. Will planting on virgin land guarantee no aphanomyces will be present?

A. It should reduce risk, but is not a guarantee of no aphanomyces.

Q. How can I know if I have aphanomyces in my field?

A. Dr. Carol Windels has developed a test to determine severity of the disease in a field. Soil samples can be sent to the University of Minnesota diagnostic lab in St. Paul for analysis. Contact your agriculturist for assistance.

Previous Crop Conclusions:

  • Lowest revenue per acre after soybeans
  • Highest revenue per acre after edible beans
  • Higherst revenue per ton after barley
  • Lowest revenue per ton after potatoes

Special thanks to Dr. Carol Windels for assistance with this issue of the Ag Notes.