The cost of some of these foliar products is also concerning. In one scenario, 16 fluid ounces is said to cost $6 per acre. If the equivalent rate of sugar was applied as corn sugar purchased in bulk, the cost would be around $0.24 per acre.

Spending $6 on 5 ounces of sugar when a corn crop uses 78 pounds of sugar for each bushel seems like a long shot for any yield effect.

While drought stress on the crop is extremely frustrating, and most producers want to try to do something... sugar most likely is not the answer.

Calculations:

•              1 bu of corn = 56 pounds and 1 bu of soybean = 60 pounds

•              16 fl oz of a foliar product (34% sugar) equals 5.44 oz of sugar. So $1.10/ fl oz of sugar = $6.00/acre

•              corn sugar or high fructose corn syrup (24% water + 55% fructose + 42% glucose) costs up to $700 / Metric Ton in bulk sales, according to alibaba.com

•              1 metric ton = 1,000 kg ≈ 722 L ≈ 24,413 fl oz (bulk density of corn sugar 1.384 kg/L)

•              So, $700 Metric Ton ≈ $0.03 / fl oz of corn sugar

•              Corn sugar is 76% sugar. If cut in half with water, the solution is 38% sugar. 8 fl oz/A of corn sugar (or 16 fl oz of 38% sugar solution) = $0.24/A (Note: this does not include a shipping charge and assumes that the cost of water is zero. If water and shipping doubled the cost of corn sugar, the bulk corn sugar is still much cheaper than the foliar product.) 

References:

•             Connor, Loomis and Cassman. 2011. Crop Ecology: Productivity and Management in Agricultural Systems. Cambridge University Press. New York. (p. 297-299)

•             Ingham, E.R. Soil Biology. The Soil Biology Primer. http://soils.usda.gov/sqi/concepts/soil_biology/bacteria.html

Furseth, B., Davis, V. M., Casteel, S. N., Naeve, S. L., and Conley, S. P. 2011. Soybean seed yield was not influenced by foliar applications of sugar. Online. Crop Management doi:10.1094/CM-2011-0615-01-BR.