ISSUE #426

426 - Harvest What You’ve Grown


Proper Defoliation Worth Over $20 Million to Shareholders in 2002

American Crystal shareholders are recognized as some of the best sugarbeet growers in the U.S., or world when it comes to raising high quality, high yielding sugarbeet crops. Sugarbeets in the Red River Valley are commonly in storage for up to 200 days or more before processing. To maximize on-farm profit it’s imperative each crop is harvested as efficiently as possible and is delivered to stockpiles in the best condition to minimize long term losses of recoverable sugar. The theme of the Agricultural Department harvest GOLD STANDARD is to “Minimize Tare and Field Losses Using Proper Harvest Methods.”

The best available estimate of shareholder defoliation practices indicates beet sample quality is significantly reduced due to poor defoliator operation. Serious weed problems in numerous fields this year make proper defoliation more critical than ever.

A reduction of 1 mph in defoliator speed of operation for all shareholders defoliating at 3 mph or greater would increase revenue by over $15,000,000. A 1,000 acre grower reducing his defoliation speed from 5 to 3 mph would realize an additional $58,500 in revenue based on the University of Minnesota research. (Table 1)

Objectives of the Defoliation Operation Are to:

  • Remove all petiole and leaf material from beet crowns.
  • Minimize root and crown breakage.
  • Eliminate loss of yield from beets knocked out of the row.
  • Sweep soil and beet canopy debris from the area adjacent to each beet row to facilitate lifting especially on the harvester row finder row.
  • Remove only the top 1/3 or a 50-cent piece size part of the crown when using scalpers.
  • Put the best storing beets possible in piles.

Table 1 on page 2 shows the impact of excessive defoliator speed on recoverable sugar per ton and grower revenue per acre. The estimates of speed of operation of defoliators was compiled by the American Crystal Sugar Company Model Farm Team.

Table 1. Economic Impact of Defoliation* 

Defoliator Speed% of AcresRecoverable Sugar/Ton*$ Per Acre LostTotal Revenue Lost
2 10% 361 $0.00 $0
3 35% 354 $31.50 $5,512,500
4 40% 346 $67.50 $13,500,000
5 10% 341 $90.00 $4,500,000
6 5% 330 $139.50 $3,487,500
      Total: $27,000,000

* Based on defoliator research by Dr. Larry Smith, University of Minnesota.

Losses in recoverable sugar per ton were primarily due to poor removal of leaf and petiole material. Just one poorly defoliated beet in 10 (3 inchs of green left on the beet) can reduce revenue by $10/acre.

Efficiency of defoliation is influenced by several factors. Grower attention to each factor will improve profitability and storage of the crop. Factors to consider when defoliating beets are:

  • Ground speed of the defoliator – 2 mph is ideal, possibly 3 under some conditions.
  • Flail condition, type, and configuration.
  • Pre-frost or post-frost situation.
  • Variety growth characteristics.
  • Need to flail or scalp.
  • Use of a flail shredder before defoliation.
  • Level of weed control.
  • Plant population.
  • Uniformity of plant spacing.

Tips For Successful Defoliator Operation

  • Slow down – excessive speed is costly, operate at 2-3 mph whenever possible.
  • Poorly adjusted and dull scalping knives cause increased yield loss.
  • Adjust defoliator settings for each field or variety.
  • Don’t use all rubber flails after a frost.
  • Take time to train defoliator operators thoroughly.
  • Change flails as needed – they won’t last the life of the machine.
  • Studded flails may damage beets and increase storage losses.

When Flail Shredder Use is Required:

Use of a flail shredder ahead of the defoliator is recommended whenever the defoliator does an inadequate job of removing all petiole material. This includes:

  • Fields with very heavy canopy growth.
  • Fields with bad weed infestations.
  • When operating defoliators at 3-4 mph or faster.
  • When defoliating after a hard frost.

Benefits of Flail Shredder Use:

  • Ability to operate the defoliator to maintain best beet quality.
  • Less fuel use with the defoliator tractor.
  • Beets store better.
  • Factory sugar recovery increased.
  • Factory operating costs reduced.
  • Much less defoliator repair and maintenance.

Defoliation Best Management Practices:

The setup and operation of sugarbeet defoliators has not received enough attention. Payments to Growers can be dramatically affected because of the impact of improper defoliator operation on crop yield and quality.

Chopping Small Grain Straw:

Another use for flail shredders is more finely chopping grain stubble after combining grain. Result is easier seedbed preparation and better stand establishment with beets.

NDSU / U of M Production Practice Survey

Please return this survey ASAP when you receive it. Information is useful for:

  • Planning educational programs.
  • Improving research planning.
  • Acquiring pesticide registrations.
  • Maintaining pesticide registrations.