Tools for Estimating Winter Malting Barley Grain Yield

ANR-95
Agriculture and Natural Resources
Date: 
02/12/2021
Greg McGlinch, Graduate Research Associate, Horticulture and Crop Science, The Ohio State University
Laura Lindsey, Associate Professor, Horticulture and Crop Science, The Ohio State University
Stephen Jacquemin, Professor, Agriculture and Water Quality Education Center, Wright State University-Lake Campus

Winter malting barley is a relatively new crop that provides farming operations an opportunity to increase crop diversity while reducing environmental impact. Demand for this crop is being driven primarily by an emerging craft brewing market that is expected to increase (Figure 1) (Brewers Association, 2020). Barley is planted in the fall with green-up in the spring. However, heaving and saturated soils caused by freeze-thaw cycles from temperature fluctuations, typical of Ohio winter and spring seasons, can reduce barley stands, generating uncertainty regarding yield potential (Zhong, et. al., 2019 & Dicksen et. al., 1979). Simple visual estimation or the “eye test” during the spring is often an insufficient assessment. A stand’s uneven or thin appearance in the spring does not necessarily correspond to lower grain yield (Goodwin et. al., 2018). The intent of this document is to provide several tools for reliably estimating yield. 

A line graph with Number of Craft Breweries in Ohio on the vertical axis and years on the horizontal axis. Number of breweries grow from less than 50 in 2011 to more than 300 in 2019.

Evaluating a barley stand in March or April, at the Feekes 5 growth stage (leaf sheaths strongly erect), is ideal because it allows farmers to determine yield potential and helps inform decisions about whether to continue to market or transition to another spring crop, like soybean. Specifically, using manual stand count methods or fractional green canopy cover (FGCC) provides farmers an easy opportunity to estimate yield potential early in the growing season. 

Barley Stem Count Method

Manual stem counts, counting the number of barley stems (main stem plus tillers), should be done at Feekes 5 growth stage in one linear foot of row (Figures 2 and 3). To ensure an accurate assessment of the stand, take stem count measurements from several representative areas of the field. Yield potential can be estimated using Figure 4. 

Measurement tool made of pipes shaped like a goal post on the ground with about ten stems between the "goal posts". Young, green barley plant showing short roots and three tall then stems with pointy tips.

Figure 2: Measurement tool to count number of stems in one foot of row.

Figure 3: Image depicting three barley stems (main stem + tillers).

Example: The average stem count for a field is 50, the count would fall in the 41-60 stem count range, relating to a potential yield between 72-91 bushels per acre (Figure 4).

Graph showing Yield in bushels/acre  (bu/ac)on the vertical axis and Stem Count (number of stems in a linear foot of row). From the left Stem counts at 20 show yields of 32 to 46 bu/ac to 80+ stems on right with yields of 97 to 113 bu/ac.

Fractional Green Canopy Cover Method

Fractional green canopy cover measures the amount of green ground cover of an area and can be done using a free mobile phone application (Figure 5) called Canopeo (canopeoapp.com) that was developed by Oklahoma State University. For a representative field stand assessment, multiple measurements should be taken at Feekes 5 capturing three barley rows in 7.5-inch row spacing. To ensure accurate readings, make sure the area is free of weeds or other obstructions. Average the FGCC percentages to establish which range the FGCC % falls within on the horizontal (x-axis) of Figure 6 to determine the yield range. 

Screenshot of app that shows canopy cover at 13.74% along with black and white heat-map type image of barley stand.

Figure 5: Image of Canopeo mobile application measuring the FGCC percentage (13.74%) of a winter malting barley stand.

Example: The average FGCC percentage is 13.74% (Figure 5), with the percentage falling in the 10-15% range, relating to a potential yield between 79-99 bushels per acre (Figure 6). 

Management Decisions

Stem counts and FGCC are additional tools for farmers to make informed agronomic decisions about their barley stands. Using these tools as guidelines provides confidence in a farmer’s decision to continue to market or transition to a different crop, reducing errors inherent in simple visual assessments of the field. It is important to monitor the barley crop through harvest as additional environmental factors can impact yield and grain quality beyond stand assessment at the Feekes 5 growth stage. Ultimately it is the farmer’s decision to plant an alternative crop based on perceived risks, commodity prices, and insurance or contracts in place. 

Graph showing Yield in bushels/acre (bu/ac) on the vertical axis and FGCC% on horizontal axis. FGGC% at the right side show 0 to 5 with a yield of 27 to 39 bu/ac to the right side with 15 to 20 FGCC% showing yields of 87 to 107 bu/ac.

References

Brewers Association. (2020). Ohio’s Craft Beer Sales & Production Statistics, 2019. brewersassociation.org/statistics-and-data/state-craft-beer-stats/?state=OH 

Dickson, A. D., Harlan, J. R., Kilngman, D. L., Moseman, J. G., Olien, C. R., Price, P. B., & Wiebe, G. A. (1979). Barley: Origin, Botany, Culture, Winter Hardiness, Genetics, Utilization, Pests.  naldc.nal.usda.gov/download/CAT79716376/PDF#page=17

Goodwin, A. W., Lindsey, L. E., Harrison, S. K., & Paul, P. A. (2018). Estimating wheat yield with normalized difference vegetation index and fractional green canopy cover. 
Crop, Forage and Turfgrass Management, 4, 1-6. doi.10.2134/cftm2018.04.0026

Zhong, B. H. W., Wiersma, J. J., Sheaffer, C. C., Steffenson, B. J., & Smith, K. P. (2019). Assessment of Winter Barley in Minnesota: Relationships among Cultivar, Fall Seeding Date, Winter Survival, and Grain Yield. Crop, Forage and Turfgrass Management, 5, 1-8. doi:10.2134/cftm2019.07.0055

Acknowledgment

Research funded by the Ohio Small Grains Marketing Program and the OARDC SEEDS grant.