Shawn Conley, WI State Soybean and Wheat Extension Specialist
While in attendance at the 2015 Commodity Classic I was a bit dismayed at the number of featured speakers expounding upon the incredible in-season benefits of applying sugar to field crops. I have been sitting on this article for a few months now waiting for the right time to relaunch the below article originally entitled “Do Foliar Applications of Sugar Improve Soybean Yield”. I waited a bit too long as my colleagues at the University of Nebraska beat me to the punch with their articles linked here “Sugar Applications to Crops – Nebraska On-Farm Research Network Results” and “Research Results: Sugar Applications to Crops“. I guess I shouldn’t feel too bad though as this is the first time the Corn Huskers have beat the Badgers in anything for a long time….
***UNL article spoiler alert*** In short the University of Nebraska team did not find a consistent yield increase in corn or sorghum and averaged 0.8 bu per acre in soybean (FYI: average cost of ground application in $7.55 and aerial is $10.60; 2015 Iowa Farm Custom Rate Survey and the average yield loss caused by sprayer wheel track damage in soybean in rows less than 20 inches is 1.9 or 1.3% with a 90 or 120 foot boom, respectively).
I also want to give credit to my colleague Chad Lee also wrote a nice article entitled “Could Sugar Help Drought Stressed Corn?” that discusses sugar rates, biological activity and actual costs of product.
I am certain this article will stir up severe indignation, however when the local cash bids are averaging $8.88 ROI is more important than ever.
Do Foliar Applications of Sugar Improve Soybean Yield (Originally published: June 14th, 2011)
High commodity prices have led growers to consider many novel soybean inputs. One input that has garnered considerable attention is the foliar application of sugar products to increase soybean yield. The objective of this research was to evaluate soybean yield in response to various sources of foliar-applied sugar across four states in the Midwest. Field research studies were conducted at Arlington, Wisconsin; Urbana, Illinois; St. Paul, Minnesota; and West Lafayette, Indiana in 2010.The four sources of sugar evaluated in this study were:
- granulated cane sugar
- high fructose corn syrup
- blackstrap molasses.
All treatments were applied at the equivalent rate of 3 lb sugar a-1 and applied at 15 to 20 gal a-1. The treatments consisted of an untreated check, all four sources of sugar applied at V4, granulated cane sugar and blackstrap molasses applied at R1, granulated cane sugar applied at V4 and R1, and blackstrap molasses applied at V4 and R1.
No positive or negative (phytotoxic) effects were visually observed on the soybean foliage at any location within 10 days following foliar applications (data not shown). Furthermore, sugar did not increase soybean yield within location (data no shown) or across locations [P = 0.60 (Figure 1)], regardless of source. While this study cannot conclusively prove foliar applications of sugar will not increase soybean yield, the authors conclude that other management strategies to improve soybean yield should take precedence over applying sugar.
The source of this data is:
Furseth, B. J., Davis, V., Naeve, S., Casteel, S., and Conley, S. P. 2011. Soybean Seed Yield Was Not Influenced by Foliar Applications of Sugar. Crop Management. Accepted: 6/1/11.
Please visit: http://www.plantmanagementnetwork.org/sub/cm/brief/2011/sugar/ to view the entire manuscript.