Kelly Arceneaux, Waltman, William F., Stapp, John, Stephenson, Daniel O., Fluitt, Jacob, Mascagni, Jr., Henry J., Harrison, Stephen A., Buckley, Blair, Leonards, James P., Price, III, Paul P, Purvis, Myra, Williams, Gregory, Padgett, Guy B., Ezell, Dustin, Collins, Fred L., deNux, Caitlin, Groth, Donald E., Fontenot, Kathryn, Harrell, Dustin L., Kongchum, Manoch
Small grain variety trials are conducted annually by scientists of the Louisiana State University Agricultural Center Agricultural Experiment Station (LSUAC) to evaluate grain yield, agronomic performance, and disease reaction of varieties and advanced lines. The trials are conducted at seven LSUAC research stations representative of the major soil and climate regions of the state. Entries are included in the trials based upon previous performance or at the request of the originating agency. Inclusion of an entry in the trials does not constitute an endorsement. Beginning in 2017, the performance trial in north Louisiana is divided by relative maturity into two groups, early and medium-late (normal). This was done to facilitate planting and harvest. The north Louisiana early trial included six varieties (bold font) and six experimental lines (normal font) while the normal trial included 26 commercial varieties and 29 experimental lines. There were 41 entries in the south Louisiana performance trials.
A fungicide split was added to the wheat performance trials at Alexandria and Winnsboro for 2020. At these locations there were six replications in each trial with three of those receiving two fungicide applications and three without fungicide.
New entries in the statewide trials are tested in the north Louisiana normal trial and in a south Louisiana vernalization trial, unless prior testing in Baton Rouge nurseries indicates an entry is adapted to south Louisiana, in which case it is also tested in the south Louisiana variety trials. South Louisiana consists of the Baton Rouge, Crowley, and Jeanerette locations; whereas North Louisiana consists of locations at Alexandria, Bossier City, St. Joseph, and Winnsboro.
When choosing varieties, growers should consult their local extension agents and choose varieties based on two-year data within a region, not based on a single year or location.
Growers should also consider specific data from the LSUAC variety trial location that most closely matches the weather and soil conditions of their farm and should avoid growing a single variety on a large acreage. Growing several varieties helps hedge against losing the entire crop to chance occurrences in weather or shifts in pathogen or pest races or virulence patterns. Yield, test weight, maturity, and disease resistance are important traits to consider when selecting varieties. If a grower plans to plant wheat early, he should avoid varieties that have a very early heading date in order to reduce the danger of freeze damage. Specific management and cultural practices for a location are presented at the bottom of the tables, along with unusual or key observations about that test. All plots were seeded at the recommended rate with seed provided by the originating agency or company (Appendix A).
Data are collected on grain yield, test weight, heading and maturity dates, plant height, lodging, and disease reaction, as appropriate at each location. Grain yield was adjusted to 13% moisture. Least significant differences (LSD's) are reported at the 10% probability level. An LSD of 10% probability (α=0.10) is the level of difference in a trait (like yield) that occurs between two varieties once in every 10 comparisons as a result of random chance due to greater soil fertility, better drainage, slightly greater harvest length, or any other "uncontrollable or unmeasurable factors" in the test, even if the varieties had the same genetic yield potential. If the LSD (0.10) for yield in a trial is 7.0 bu/a, there is a 10% chance that two varieties with a reported yield difference of 7.0 bu/acre are genetically equal and a 90% probability they have differences in genetic potential in that particular environment. LSD values are influenced by the degree of precision that soil fertility, stand establishment, plot length, harvest efficiency, and other variables of the trials are controlled, and by the number of replications of each variety or treatment. The letters 'NS' are used in the text and Tables to indicate lack of significance (not significantly different) at the 10% probability level. Correlations are sometimes given to indicate the degree to which two traits, such as rust rating and yield, are related. A correlation between rust rating and yield of r = -1.0 would indicate that for every unit increase in rust there was a proportional decrease in yield.
Wheat leaf rust, stripe rust, and oat crown rust are reported as percentage of the upper two leaves affected by the disease. Two replications are evaluated for leaf rust, between flowering and the early dough stage of kernel development. Wheat and oat stem rust are reported on a scale of 0-9, where a 0 indicates no disease and a 9 indicates that the plant was killed by the disease. Stem rust is normally rated somewhat later than leaf rust.
Bacterial streak, Septoria leaf and glume blotch are rated on a scale of 0 to 9 during the dough stage of development. A rating of 0 indicates that no disease was present, while a 9 indicates very severe disease. The upper few leaves, heads, and stems below the head are the portions rated for these diseases. Since bacterial streak (black chaff) is not controlled by fungicides, it is important that this disease be distinguished from septoria blotch. Heading day is given as calendar day (day of year). Lodging is rated on a 0-9 scale, where a 0 indicates that all plants were completely upright. Fusarium headblight is rated on a 0-9 scale in yield plots and in inoculated, misted nurseries. A seed sample from the yield plots is rated for percent Fusarium Damaged Kernels (FDK) and them submitted to the USDA Wheat DON Lab at the University of Minnesota to determine Deoxynivalenol toxin (DON) concentration. The same procedure is followed for the misted nurseries except that samples are hand harvested and processed to avoid blowing out small, scabby seed.
|Yield||BUPA||Grain yield in bushels per acre adjusted to 13% moisture.|
|Test weight||TWT||Volume weight of grain in pounds per bushel|
|Heading day||HD||Day of calendar year (days after December 31) at 50% heading.|
|Growth Habit||GH||Normally taken on oat trials where a lower number indicates earlier and more upright growth habit and a high number indicates a prostrate growth habit during early or mid-winter. Higher numbers may be indicative of winter hardiness.|
|Relative Maturity||RELMAT||Relative Heading Date on a 0 - 9 scale where a lower number is earlier, taken after flag leaf stage and before maturity. Normally taken for trials that are not rated every week due to distance.|
|Vernalization||VERN||An indication of the degree of heading when not all varieties head properly. Rated on a 0 – 9 where a higher number indicates more normal heading and a lower number indicates heads emerged unevenly of not at all.|
|Plant height||HT||Plant height in inches.|
|Lodging rating||LOD||Lodging rated on a scale of 0 - 9, where a 0 indicates no lodging and a 9 indicates complete lodging (all plants flat).|
|Leaf rust||LRFUST||Percent of upper two leaves affected by leaf rust, rated during grain fill. This rating is generally taken during soft to mid-dough, but varies somewhat by location and variety.|
|Stripe rust||STRUST||Percent of upper two leaves affected by stripe rust, rated between flag leaf and mid grain fill.|
|Septoria||SEPT||Septoria leaf & glume blotch rated on a scale of 0 - 9, where 0 indicates no disease and 9 indicates severe disease on the flag leaf and head.|
|Bacterial Streak||BACT||Bacterial streak (black chaff) rated on a scale of 0 - 9, where 0 indicates no disease and 9 indicates severe disease on the flag leaf and head.|
|Fusarium Headblight||FHB||FHB is rated on a scale of 0 - 9, where 0 indicates no disease and 9 indicates severe disease on the head.|
|Fusarium Damaged Kernels||FDK||Is measured as the percent of grains shriveled and discolored by FHB|
|Phenotype||PHE||Phenotypic rating, an overall visual rating prior to harvest. 0=poor, 9=excellent. This rating is a visual rating of ‘eye-appeal’.|
The 2019-2020 growing season is not one that we ever want to repeat. The season got off to a good start with favorable conditions for planting at all locations. The winter was quite wet in south Louisiana, and plots generally did not tiller and fill in as much as desired. The Crowley location was severely damaged by herbicide drift and did not produce useable data. The Baton Rouge location was not harvested because plots were too thin and variable to produce usable data. Given the concerns over Covid-19 and limitations on available field help, it was decided to concentrate on getting breeding material and seed increases harvested and not waste time harvesting yield plots that would not produce good data. The Alexandria location was demolished by a tornado that destroyed building and crops in mid-April. The Bossier City location was lost to herbicide drift in mid-winter. The Winnsboro location was very good all year and produced solid wheat data.
Oat variety trials were lost at Bossier City and Alexandria to herbicide drift and a tornado, respectively. The oat trial at Baton Rouge suffered from season-long water-logging stress and produced low grain yields. The trials at Winnsboro were not harvested due to 100% lodging caused by a severe stem rust epidemic coupled with strong storms prior to harvest.
Test was not harvested due to poor and uneven stands resulting from winter-long excessive rainfall. Data was collected on agronomic traits and is included in means tables.
The Crowley test sustained significant herbicide drift in the spring that resulted in low yields and a high degree of error variance. Grains yields at Crowley ranged from 14.0 to 32.9 bu/acre and the CV was 37%. As a result, that data is not reported.
The Jeanerette trial produced grain yields ranging from 21.6 to 41.5 bu/acre (Table 1). Delta Grow 3500 and AGS 2055 were the highest yielding commercial varieties. Test weights were quite variable with a range of 39.8 to 60.3 lbs/bu. Part of the variation in test weight can be attributed to a very wide range in heading dates. The earliest heading date was 69 (March 9) to 106 (April 18). The earliest and latest heading entries were generally the lowest yielding. All entries with heading dates greater than 100 days fell in the lowest 20% for yield.
AR06146E-1-4 had the highest two-year mean yield across south Louisiana (Table 2) and the fourth-highest test weight. Go Wheat LA754, Liberty 5658, Dyna-Gro Plantation, and Delta Grow 3500 also had yields greater than 54 bu/acre. Test weights were a little low with an average of 55.9 lbs/acre. Four breeding lines had test weights of 58 lbs/bu or greater. Only one entry had a two-year mean heading date over 100 days.
Ten wheat varieties have been evaluated in south Louisiana for each of the past three years (Table 3). AGS 2055 which was included in the trial as a later-heading check, had the highest mean yield (78.2 bu/acre). The test average yield was 72.4 bu/acre. Test weights ranged from 54.6 to 59.9 lbs/bu with a mean of 58.0. FHB and leaf rust pressure have been relatively low and only one entry had significant leaf rust.
Test not harvested due to a tornado in mid-April that destroyed plots.
This test was abandoned due to herbicide drift.
Yields of the twelve entries evaluated in the early-heading variety trial at Winnsboro were excellent (Table 4). The six reps were split with three receiving two applications of a foliar fungicide. The second fungicide application was timed at average flowering date for maximum FHB control. The average yield in the fungicide protected split was 80.8 bu/acre, which was 18.5 bu/acre higher than the mean for the non-protected split. The breeding line FL14167LDH-158 had the highest yield(87.8 bu/acre). AGS 3000 and Pioneer 26R94 also yielded over 84 bu/acre. AGS 3000 had the highest test weight (59.3 lbs/bu).
FL14167LDH-158 had the highest yield in the non-protected split (69.1 bu/acre). The yield response from fungicide application ranged from 12.5 bu/acre to 27.9 bu/acre with a mean response of 18.5 bu/acre. Test weight was also increased with fungicide application with a mean increase of 3.0 lbs/bu and a range of 1.5 to 5.9 lbs/bu. Four entries in the fungicide spilt had test weights above 58.0 lbs/bu whereas all 12 entries in the non-fungicide protected split had test weights below 57.0 lbs/bu. The two later-heading checks had the lowest test weights, which may have resulted from higher grain moisture at harvest. The combined impact of fungicides on yield and test weight are very significant and may be the difference between a profit and a loss.
There was very little leaf or stripe rust present at Winnsboro in 2020. Frequent spring rainfalls did result in significant FHB pressure with an average Fusarium rating of 3.8 and 6.2 (0-9 scale) in the protected and non-protected yield plots, respectively. The greatest test weight response to fungicide application was in varieties that had the highest FHB ratings.
Fusarium Damaged Kernels (FDK) ranged from 3% to 17.5% in the protected plots and from 5% to 30% in the non-protected plots. Fungicide application reduced FDK by an average of 5.9% in the yield plots. All variety trial entries were also screened for FHB reaction in a misted and inoculated nursery that creates very heavy disease pressure.
The average FDK in the screening nursery was 16.1% compared to 9.0% for the non-protected yield trial. The range was 3% to 42.5%. DON data has not been completed.
North Louisiana Early Trial Two Year
The average yield of 10 entries tested for two years in the early-heading trial was 64.1 bu/acre (Table 5). Test weights were low with a mean of 54.4 lbs/bu. FDK in the yield plots ranged from 6% to 45% with a mean of 19%. In the disease screening nursery FDK averaged 40% with a range of 14% to 68%. High FDK entries also had high concentrations of DON.
North Louisiana Early Trial three year
Six entries have been tested in the North Louisiana early performance trial for three years (Table 6). AGS 2055, a medium late-heading check, had the highest three-year mean yield (79.4 bu/acre). Delta Grow 3500 had the highest yield of the early-heading entries. FDK in the misted nursery ranged from 28% to 52%.
The Alexandria test was not harvested due to a tornado in mid-April that destroyed plots. Table 7 contains heading date, stem rust ratings and FHB data for misted and yield trials. FDK in the misted nursery ranged from 1% to 50% with a mean of 11.5%. The lines with FDK greater than 30% all headed earlier than the test mean. This may be a reflection of inherent susceptibility of these entries but could also be confounding of heading date with tornado induced lodging and presence of conditions favorable for disease development.
This test was abandoned due to herbicide drift.
Yield in the fungicide split of the normal maturity variety trial was excellent with a mean of 79.2 bu/acre and a range of 67.3 bu/acre to 91.9 bu/acre (Table 8). Pioneer 26R45 had a yield of 88.0 bu/acre in the fungicide split. Five other entries had yield means greater than 87.0 bu/acre led by Progeny PGX19-12. The average yield in the non-protected split of the trials was 67.0 bu/acre, 12.3 bu/acre lower than the mean of the protected split. Fungicide protection also boosted test weight with a mean increase of 2.3 lbs/bu and a range of -1.0 to +6.6 lbs/bu. The entries with the greatest test weight response to fungicide were generally those with the highest FHB and FDK ratings. This was not necessarily the case for yield response. Susceptible entries generally had higher response to fungicide application, but even the FHB resistant entries showed responses of 10+ bu/acre. There was a significant variety by fungicide interaction for yield which indicates that the entry response to fungicide differed among varieties.
FDK in the misted screening nursery ranged from 1% to 53%. The two entries with the highest FDK also had the lowest yields in the non-protected split. The highest-yielding lines had low levels of FDK in the misted nursery.
Thirty-one entries have been tested in Winnsboro for two years (Table 9). The average yield was 73.3 bu/acre with a range of 63.5 bu/acre to 84.0 bu/acre. Pioneer 26R45 had the highest mean yield. The average test weight was 55.3 lbs/bu with a high of 58.3lbs/bu and a low of 51.8 bu/acre. There was a pretty strong correlation between low test weight and high FDK. DON concentrations (2019 data only) ranged from 2% to 26% in the misted nursery.
North Louisiana Normal Trial 2020
Table 10 is essentially a repeat of Table 8 since the only yield data for 2020 came from Winnsboro. The Table does present the misted nursery data averaged across both locations.
North Louisiana Normal Trial Two Year
Table 11 contains data for the normal maturity wheat trial across North Louisiana for two years. The average yield ranged from 61.7 bu/acre to 74.4 bu/acre with a mean of 67.9 bu/acre. Despite a low Coefficient of Variation (CV), yield differences are not significant in this analysis. This is because there was a large variety by experiment interaction and the relative ranking of varieties changed with environment.
Stripe rust was significant in 2019 with ratings up to 25% and therefore included in this table. FDK in the yield plots ranged from 1% to 50%. The five lines with FDK of greater than 37% in the yield trials had test weights less than 53 lbs/bu. The average test weight was 55.0 lbs/bu. Higher-yielding entries generally had higher test weights and lower FDK.
In the misted nursery FDK values ranged from 8% to 57% with a mean of 27%. FDK from the normal yield plots and the misted nursery were highly correlated. The misted nursery values are always higher, and the nursery generally minimizes confounding with heading date. DON concentration ranged from 2 ppm to 25 ppm.
North Louisiana Normal Trial Three Year
AGS 2055, USG 3640, AGRIMAXX 492, and PIONEER 26R59 have three-year mean yields greater than 80 bu/acre across North Louisiana (Table 12). The average yield of 18 entries was 76.9 bu/acre and differences among entries are not significant because of large variety by test interactions. This means the rankings and relative differences between varieties has been inconsistent from one environment to the next. The 2018 production environment was problem free and produced very high yields, while in the last two years there were FHB and rainfall issues. What this really means is that the variance in yield caused by the interaction of entry and environment are greater than the variance caused by variety. FDK in the misted nursery ranged from 8% to 48% with a mean of 25%.
Fusarium Headblight has been the most important disease of wheat in Louisiana for the past five years. FHB decreases yield, lowers test weight, and can result in rejection of the crop at the point of delivery. In Table 13, wheat varieties are classified as Resistant (R), Moderately Resistant (MR), Moderately Susceptible (MS), or Susceptible (S) based on a combination of ratings for FHB head symptoms, FDK and DON from two or more years in the misted nurseries. Incidence of FHB was high in 2019 compared to 2018 and 2020. DON data from 2020 has not been added to this table yet due to Covid-19 related delays in the USDA lab where samples are tested. This data will be added, and the tables updated when the DON testing is completed.
The best way to control FHB is to select varieties that have at least a moderate level of resistance and apply one of the fungicides shown to be effective at heading. The effect of varietal resistance is additive with the effect of the applied fungicide and should be adequate to prevent significant losses.
Liberty 5658 and the breeding lines AR06146E-1-4 and LA12080LDH-72 are classified as Resistant to FHB. Six entries in the trials are classified as Moderately Resistant and eight more are classified as MR/MS. Data is present from 2020 for 24 entries that have only been tested for one year. These will be classified after an additional year of testing.
There were 28 entries in the statewide oat performance trials across four locations for 2020. The average yield at Baton Rouge was quite low (Table 14) with a mean of 26.8 bu/acre and a high yield of only 56.9 bu/acre. A very wet winter and spring resulted in retarded growth and reduced tillering. Late spring storms caused near 100% lodging. Most plots did not have sufficient seed to determine test weight. Crown rust incidence was very high on the susceptible variety Brooks, but all other entries showed good resistance. Stem rust started in early winter and occurred at significant levels on many entries.
The oat variety trial at Winnsboro (Table 15) was not harvested due to severe (100%) lodging resulting from a combination of strong storms in late spring and very heavy stem rust infection. Crown rust also developed at this location but only on the susceptible variety Brooks.
See PDF for the tables.