Oat Variety Trial under Organic Management: Increasing Profitability for Organic Producers in the North Central Region

Jesse Hall’s farm, Arlington, SD

At the South Dakota location, the 2017 growing season was characterized by lower moisture than normal from June to harvest. The field was in the third year of transition for organic certification. Averages for the different traits measured during the 2017 growing season are presented in Table 2. Excessive weed pressure in 2018 resulted in poor grain yields and a CV >20% (data are not reported).

In 2017, average grain yield ranged from 74.8 bu/acre for Hayden to 26.0 bu/acre for Reins with a trial average of 60.9 bu/acre. No fertilizer was applied during the growing season. Based on a soil test performed at the beginning of the growing season, the amount of nitrogen in the soil (22 pounds/acre) was much lower than recommended for oat production. Plots of the variety Reins were severely damaged by rodents which explains its low yield performance in this trial.

Average test weight ranged from 32.2 lb/bu for Reins to 37.4 lb/bu for Rockford. Varieties with high test weight included Rockford, Hayden, Antigo, Goliath, Leggett, Sumo, and Natty.

Table 2. On-farm oat variety trial under organic management, Arlington, SD, 2017.

A 0.25 m² area was cut at about 0.5 inch from the soil surface around growth stage Feekes 11.1. Oat plants were separated from weeds and clover. Oat biomass was significantly different among varieties. The breeding line OT8006 had the highest plant biomass while Reins had the lowest. There was a significant effect of variety on weed biomass with Leggett having the least weed biomass and Antigo having the highest weed biomass. Plant height and oat biomass were not significantly correlated with weed biomass. However, there was a significant negative correlation between weed biomass and heading date. There was no significant effect of variety on the clover biomass, likely because the clover was relatively small at Feekes 11.1. The effect of variety on clover biomass should likely be evaluated at a later stage of clover development.

Mark Doudlah’s farm, Evansville, WI

Averages for traits measured during the 2017 and 2018 growing seasons are provided in Table 3.

Table 3. On-farm oat variety trial under organic management, Evansville, WI, 2017 and 2018.

In 2017, grain yields ranged from 129.5 bu/acre for Deon to 72.3 bu/acre for Oravena. In 2018, yields were lower than 2017, ranging from 77.7 bu/acre for Betagene to 22.8 bu/acre for Rockford. Overall, the highest yielding cultivars were Betagene, Deon, and Saddle. Test weight ranged from 38.5 lb/bu for Antigo to 28.6 for OT8006. Antigo (38.5 lb/acre) and Sumo (37.3 lbs/acre) exhibited excellent test weight with good yield potential.

University of Wisconsin, Madison, WI

 Data collected in Madison is reported in Table 4. Yields are not reported due to high variability (CV > 20%). Crown rust infections were present at that site and the severity for each cultivar is reported. In susceptible cultivars, infection with crown rust can cause severe yield loss and significantly reduce test weight. Because conventional fungicides can’t be applied in organic production, it is recommended to choose a cultivar resistant to crown rust. Antigo, Deon, Leggett, Saddle and Sumo are cultivars with good levels of resistance to crown rust (Table 4).

Table 4. Oat variety trial under organic management, Madison, WI, 2018.

University of Minnesota, Lamberton, MN

Table 5. Oat variety trial under organic management, Lamberton, MN, 2018.

Grain yield ranged from 90.4 bu/acre for Betagene to 35.5 bu/acre for Leggett. Test weight ranged from 37.7 lb/bu for Sumo to 30.4 lb/bu for Rockford. Similar to the Evansville site, the top two highest performing cultivars for grain yield were Betagene and Deon, with Deon having higher test weight than Betagene.

End-use quality characteristics

Grain quality characteristics are important for marketing organic grain to the milling industry. Grain quality characteristics were collected on samples from Arlington, SD and Evansville, WI in 2017, and from Lamberton, MN, Evansville, WI, and Madison, WI in 2018. The average for each variety over all five environments is reported in Table 6. Grain with a high thousand kernel weight, a high proportion of plump kernels and a low proportion of thin kernels is desirable for milling. Betagene, Oravena, and Sumo produced grain with thins under 5 % and plumps over 50%. Antigo, Newburg, Rockford, Saber, and Souris had a high proportion of thins in their grain (>15%). Thousand kernel weight ranged from 40.1 g for Oravena to 25.6 g for Antigo. The hull covering the groat in oat grain is removed as a by-product during the milling process. Varieties with high groat percent will result in higher milling yield and are therefore more desirable for the milling industry. Groat percent ranged from 67.2% for Saddle to 55.1% for OT8006.

High protein and beta-glucan contents are desirable for nutritional quality. Groat protein content ranged from 17.2% for Antigo to 13.3% for Hayden. Betagene and Natty had the highest (5.5%) and lowest (3.8%) groat beta-glucan content, respectively. Groat oil content ranged from 6.5% for Rockford to 3.8% for Natty.

Table 6. Average end-use quality characteristics for 20 oat cultivars evaluated under organic management in MN, SD, and WI.

Summary

Objective 1: Identify oat varieties that will provide the best profitability for organic producers in the North Central region.

Based on these trials, varieties that are recommended for organic production include Betagene, Deon, Saddle, Antigo, and Sumo. Betagene, Deon and Saddle had the highest yield potential. Test weight for Betagene was low and may be a limitation for meeting the test weight requirement set by the industry. On the other hand, Antigo and Sumo had excellent test weight. Saddle has excellent straw strength. Deon, Saddle, Antigo, and Sumo exhibited good levels of crown rust resistance. Saddle, Antigo and Sumo are early-maturing cultivars while Betagene and Deon are mid- to late-maturing cultivars. The two cultivars from Canada specifically developed for organic production were very late (especially OT8006) and are therefore not recommended for production in this region.

Weed management of variety trials under an organic system is more complex than in conventional systems.  In several of the trial locations, experimental error for yield was too high to use the data for making recommendations.  Only 4 environments over 3 states were used to evaluate yield performance.  While the trials performed as part of this grant resulted in valuable information, the evaluation of cultivars under organic management system should continue over several years to fully evaluate cultivar stability and to develop recommendations for specific production areas in the region.

Objective 2: Identify oat varieties that exhibit good end-use quality so that organic grain produced meets market requirements.

For the milling industry, grain specifications generally include a minimum test weight and a maximum amount of thins.  Antigo, Sumo, Saddle, and Deon are likely to meet the test weight requirement. Fan speed can be increased on the combine to increase test weight if necessary.  The percent thins was 10% or below for Deon, Saddle, and Sumo while Antigo was characterized by high levels of thins. Betagene had excellent beta-glucan concentration.  Antigo and Sumo had high protein content. Sumo exhibited excellent milling quality characteristic, but beta-glucan content was low.

Objective 3: Identify oat varieties that can compete with weeds.

Based on the trial performed on Jesse Hall’s farm, varieties with lower weed biomass (potentially higher ability to compete with weed) included Goliath, Newburg, Oravena, Rockford, and Leggett. Those cultivars are leafy and late-maturing.

Because the weed biomass study was done at only one site-year, it would be necessary to repeat this experiment in order to confirm these results.

Objective 4: Communicate our results with growers throughout the region by publishing results on extension websites of three universities, presenting results at field days in the three states, and presenting at one regional meeting/conference.

An extension publication was developed and was published on the extension website of South Dakota State University (https://extension.sdstate.edu/sites/default/files/2019-05/P-00107.pdf). Print-outs of the extension publication will be distributed at field days in the three states.