May 3, 2013 Field Crops 28.9 - 115

Evaluation of Ascend®: Hormones that stimulate corn growth

Joe Lauer, Corn Agronomist

During years with strong grain prices numerous products appear that seem too good to be true. If there was any growing season when a corn root growth enhancer should work it was during the  drought of 2012. Ascend® is touted as a "... tool to increase plant efficiency" and "... can stimulate higher yields through a larger root mass ..."

Ascend® contains the plant growth regulators cytokinin (0.09%), gibberellic acid (0.03%) and indole butyric acid (0.045%). It can be applied on the seed, in-furrow at planting, 2x2 or 3 inches below the seed at planting, at the 3-4 leaf stage and/or at the 8-11 leaf stage.

We tested the plant growth regulator Ascend® by applying it to an adapted hybrid and comparing it to the same hybrid left untreated at eleven locations in Wisconsin. Applications were made at the labelled rate and timing of 3.2 oz/A at V3-V4. Locations that exhibited significant drought stress included Chippewa Falls, Lancaster, Janesville, Arlington and Fond du Lac. Hancock was an irrigated site.

At seven of eleven locations there was no statistical difference when using Ascend®. At three of eleven locations, the untreated plots yielded more than plots treated with Ascend®. At one of eleven locations, Ascend® treated plots yielded more than untreated plots.

Table 1. Corn grain yield response of an adapted corn hybrid treated with Ascend® plant growth regulator to an untreated check during 2012.

Location Ascend® (bu/A) Untreated (bu/A) Difference (bu/A) LSD(0.10)
Arlington 227 229 -2 NS
Chippewa Falls 135 149 -14 5
Coleman 261 270 -9 NS
Fond du Lac 203 202 +1 NS
Galesville 226 225 +1 NS
Hancock 224 218 +6 6
Janesville 136 146 -10 NS
Lancaster 159 178 -19 10
Marshfield 145 157 -12 11
Seymour 200 201 -1 NS
Valders 243 223 +20 NS

At none of the sites that had significant drought stress during the growing season did Ascend® stimulate higher yields. Across all locations there was no statistical difference between corn treated with Ascend® (196 bu/A) and untreated corn (200 bu/A).

Further Reading

For details of the experiments see

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