Sugarbeet defoliation is an important component of harvest

Good defoliation will improve sugarbeet quality, storability and grower profitability.

The MSU Sugarbeet Advancement program has worked closely with dozens of producers in numerous research trials in the last several years. It has become apparent that many producers do not put the same emphasis on properly maintained, adjusted and operated defoliators as they do with harvesters. Green petioles on the beets will increase impurities and storage losses. Poor clear juice impurity will reduce the amount of extractable white sugar. If the Michigan Sugar Cooperative could increase recoverable white sugar per ton by only one pound per ton, four million pounds more sugar could be marketed valued at over 1.6 million dollars.

A well-maintained topper is a key component to excellent topping. Flails that are worn or broken should be replaced. They should also be tight on the row unit. Flails that are loose will separate or split when going over the crown and leave additional green matter. Often, we have seen topping being better earlier in the season and as flails wear, topping becomes poorer later. This is especially concerning since we will then be putting those tops in permanent piles, which will effect long-term storage. Flails should be replaced as needed throughout the harvest season.

Toppers should be adjusted every time a field is entered and whenever varieties change. Crown height is different between varieties and also with plant population levels. Thin beets will stick out of the ground further than thick stands. Rhizoctonia infection will make topping difficult when trying to minimize knockouts. Some conditions such as high populations, dehydrated or frosted beets will also make topping more difficult. In these situations, toppers may need to be set a bit lower, PTO speeds increased and a decrease in ground speed may be needed. A general rule of thumb is topping speed should not exceed 4 miles per hour.

The sugarbeet harvester operator should always be in close communication with the person operating the topper. If adjustments are needed, they should be communicated appropriately. It is also important that the topper operator not be too far ahead of the harvester. Sugarbeets that are topped during a bright, sunny day quickly increase in temperature from solar radiation. Warmer beets will respire faster, burning sugar and reducing storability. Keeping no more than one to two rounds ahead of the harvester would be ideal.

Michigan Sugar Company research has shown an additional 11 pounds of sugar from good topping compared to poor. Sugarbeet Advancement research has shown between 4 to 9 pounds additional recovery per ton. If a conservative 4 pounds per ton of additional sugar is recovered from better topping, a 25-ton crop would pay a grower over 22 dollars per acre. Taking a little extra time to do a good job in topping sugarbeets can pay good dividends!

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