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Foliar application of branched-chain amino acids on creeping bentgrass


Foliar application of branched-chain amino acids

Photos by Isaac Mertz

The branched-chain amino acids (BCAA) leucine, isoleucine and valine are synthesized in plants and are essential to growth in most organisms. Plants can absorb foliar applications of these compounds; however, plant catabolism of BCAA is not completely understood. The BCAA compounds contain nitrogen (N) in their chemical structure and have potential as an organic N source for plants.

The objective of this study was to investigate creeping bentgrass (Agrostis stolonifera L.) responses to foliar applications of BCAA. Treatments included two ratios of BCAA, urea and an untreated control.

Creeping bentgrass plugs from a sand-based putting green were transplanted to pots and allowed to re-establish in the greenhouse for seven days before being treated. All treatments were applied on a 14-day interval, at an equal nitrogen rate of 3.4 kilograms N/hectare. All samples also received an application of 3.4 kilograms N/hectare (from urea) halfway through the 14-day interval after each treatment application.

At trial’s end (42 days), plants that had received applications of leucine, isoleucine and valine in a 4:1:1 ratio exhibited a 37% increase in rooting and a 27% increase in shoot density compared with plants receiving only urea. When leucine, isoleucine and valine were applied in a 2:1:1 ratio, rooting increased only 18% and shoot density increased 13.5% (compared with urea-only treatments).

These results suggest the BCAA could be a suitable organic nitrogen source for creeping bentgrass.

— Isaac Mertz; Nick E. Christians, Ph.D.; Adam Thoms, Ph.D.; and Ben Pease, Iowa State University, Ames

Editor’s note: Earlier versions of these summaries were published in the 2016 ASA-CSSA-SSSA Meeting Abstracts, ASA, CSSA and SSSA, Madison, Wis.

Teresa Carson is GCM’s science editor.