Durum cultivar evaluations for the Western Golden Triangle area of Montana

Principal Investigator: Gadi V.P. Reddy, Professor of Entomology/Ecology, Western Triangle Ag Research Center

Personnel: John H. Miller, Research Scientist, Julie Prewett, Research Assistant, WTARC, Conrad, MT, and Mike Giroux and Andrew Hogg, MSU PSPP Dept., Bozeman, MT.

Objectives: The objective is to evaluate durum varieties under the local conditions with respect to yield, test weight, plant height, and seed protein. The research center strives to provide growers of the western triangle area unbiased information of various durum varieties.

Methods: Plots were seeded with a four row plot seeder on one foot spacing and planted on no- till chemical fallow barley stubble. Plots were trimmed, measured for length, and then harvested with a Wintersteiger Classic plot combine. Durum wheat seed was cleaned prior to collecting data.

Results: Results are tabulated in Tables 1 and 2. Table 3 is the soil test results from each location.

Overall, the crop year temperatures where cooler than 32 year average at the research center, May, when we could have used some cooler temperatures, was 5.2 degrees warmer than the average. But the overall average temperature for the year from September to August was 3.8 degrees cooler than the 32 year average. The winter temperature, from September to March was well below average, with February being 15.5 degrees colder than the 32 year average. March and April were 9.6 and 7.1 degrees colder than the 32 year average. May was the only month that had a temperature that was above the average with a temperature 5.2 degrees. September through March were at or above the average precipitation for those months. Then May through August were drier than the 32 year average. Overall, precipitation was average for the year with respect to the 32 year average.

The durum plots were seeded into soil that had good soil moisture storage from the late summer and fall moisture in 2017. Overall, the durum did well this year. Late seeding, a warmer and dryer May and lack of summer moisture probably affected test weight and seed protein.

Durum yields ranged from 76.1 to 51.2 bu/acre (Table 1). With Montana State University line MTD16006, Riveland, and MTD16007 being the top three yielding varieties at 76.1, 75.3, and 70.5 bu/ac. The 2018 yields were about 3.8 bu/ac higher than the five year average (Table 2). Test weights were 0.2 lbs/bu lighter than the long term average. Durum seed protein was 1.2 percent higher than the five year average.

Summary: The data from the off station plots is supported by the local producers and advisory committee as well as the seed industry. It is planned to continue the off station variety plots at the same locations as the environmental conditions at each location are unique to the western triangle area. No insect incidence or damage was noticed in any of the varieties.

These data should be used for comparative purposes rather than using absolute numbers. Statistics are used to indicate that treatment or variety differences are really different and are not different due to chance or error. The Least Significant Difference (LSD) and Coefficient of Variability (CV) values are useful in comparing treatment or variety differences. The LSD value represents the smallest difference between two treatments at a given probability level. The LSD at p=0.05 or 5 % probability level is usually the statistic reported, and it means that the odds are 19 to 1 that treatment differences by the amount of the LSD are truly different. The CV value measures the variability of the experiment or variety trial, and a CV greater than 15 % indicates a high degree of variability and less accuracy.

Funding Summary: Office of Special Projects will provide expenditure information. No other grants support this project.

Table 1. Durum Variety Trial located WTARC. Pondera County. Western Triangle Ag.

Research Center. 2018.

Cooperator and Location: WTARC Pondera County.

Planted on 5/4/2018 on chemical fallow barley stubble. Harvested 8/23/2018.

Fertilizer, actual lbs/ac: 11-22-0 applied with seed and 230-0-20 side shot while planting. Fertilizer rates are based on a yield goal of 70 bu/ac.

Herbicide: The plot area was pre-plant sprayed with 40 oz/ac RT3 on 5/3/2018. Precipitation from seeding to harvest: 4.92 inches

1 Yield and test weight are adjusted to 13% seed moisture. Conducted by MSU Western Triangle Ag. Research Center.

Table 2. Five-year means, dryland Durum varieties. Western Triangle Ag. Research Center Conrad, MT, Pondera County, 2012 – 2015 and 2017.

1 Days from seeding to heading.

Table 3. Soil test values for off-station and on-station plots, 2018.

1Nitrogen soil samples were to a depth of four feet in one foot increments. All other soil tests were for zero to six inches in depth.

WTARC- Western Triangle Ag. Research Center