I ntroduction. Oat Hay Variety Trial R.L. Dovel, J. Rainey, and G. Chilcote'

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1 Oat Hay Variety Trial R.L. Dovel, J. Rainey, and G. Chilcote' I ntroduction Oat hay is an important commodity in the Klamath Basin. An increasing acreage of oat hay is being produced in the basin. Oat hay variety trials were conducted at KES in 1989 and Since that time, several new oat varieties have been released for grain production and some oat varieties have been released specifically for hay production. A variety trial examining the hay yield potential and forage quality of standard and newly developed varieties is needed to provide producers with a basis for variety selection. Oat hay variety trials were established at KES in 1994 and 1995 to examine the forage yield and quality of oat varieties. Procedure The trials were established at KES on Fordney fine sandy loam that is moderately deep and somewhat poorly drained. The previous crop was potatoes. The crop was irrigated by a solid set sprinkler system. The trials were arranged in a randomized complete block design with four replications. Seed was planted on April 20 in 1994 and May 23 in Seed was planted to a depth of 1 inch at a seeding rate of 100 lb/acre. All plots were fertilized with 50 lb N, 62 lb P 205, and 37 lb S / acre at time of seeding. Plots measured 5 x 20 feet with a row spacing of 6 inches. Bromoxynil and MCPA were applied at labeled rates to control broadleaf weeds. Plots were harvested when Magnum oat plants reached the soft dough stage in In 1995, there were two harvest dates. Plots that were in the soft dough stage were harvested on August 10. All remaining plots were harvested on August 23. Prior to harvest, plots were trimmed to 17 feet long. The crop was harvested using a flail harvester with a three-foot wide head. All yields were reported on a dry weight basis. Subsamples were collected and analyzed for forage quality measured as, acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP), and relative feed value (RFV), using a near-infrared reflectance spectrophotometer. Results Variability was high in the trial in 1994, making variety separation difficult. The highest yielding variety, Magnum, was not significantly different than eight other varieties (Table 1). The only two entries with significantly lower yield than Magnum in 1994 were Magnum II and Dusty. These two varieties are very short season while Magnum is a late maturing variety. Harvesting all entries when Magnum was at soft dough resulted in the early varieties reaching stages too advanced for optimal production. This is reflected in the lower CP and higher fiber content of the earlier maturing varieties. In 1995, Westford hooded barley and Byrd were the two highest yielding entries in the trial (Table 2). They produced significantly higher forage yields than the five lowest yielding entries. The trial was harvested when most varieties were in the soft dough stage in Associate Professor, Biological Sciences Research Technician III, and Research Technician, respectively, Klamath Experiment Station, Klamath Falls, OR. KLAMATH EXPERIMENT STATION

2 Oat Hay Variety Trial Dusky, the earliest maturing oat variety in the trial, was harvested on August 10 with the hooded barley entries (Table 2). All other oat varieties were harvested on August 23 when the majority of oat entries were at soft dough. Magnum, a late maturing variety, was not yet at the soft dough stage and yields were suppressed when compared to the previous year. When Dusky was harvested at an appropriate stage in 1995, it yielded much better than in 1994, and also produced better forage quality values. It appears that Dusky would be a good oat variety for short season oat hay production. The hooded barley entries would also be an excellent choice for short season cereal hay production. When averaged over a two-year period, Magnum, Cayuse, and Otana were the highest yielding entries. There was a large group of entries that were slightly lower yielding than the top group. They include most grain varieties currently in use in the Pacific Northwest. It is interesting to note that Ajay, a semi-dwarf variety, is in this group. In spite of its short stature, Ajay produced forage yields comparable to all but the two highest yielding entries (Table 3). Due to its short stature, there is less stem and a higher percentage of leaves in Ajay than in taller varieties. This resulted in higher than average forage quality values for the short variety. Although forage yield was higher in 1994 than in 1995, forage quality was highest in This is due largely to harvesting at a more appropriate time in 1995, while harvest was delayed past the appropriate time for many varieties in Average crude protein concentration in the 1995 trial was 10.0 percent compared to 7.3 percent in ADF, which is a predictor of forage digestibil- ity and thus animal performance, averaged 35.0 in 1995 and 41.3 in 1994, indicating that feeding oat hay produced in the 1995 trial would result in better animal performance than that produced in the 1994 trial. Minimal nutritional requirements for a dry pregnant cow in the middle third of pregnancy are 7.0 percent crude protein and 48.6 percent TDN, which corresponds to 55 percent ADF. Oat hay produced in both years was adequate to meet the energy needs of a dry cow, but hay from 1994 was only marginally adequate in crude protein. Crude protein concentration of some varieties dropped below minimal levels in The variability in forage quality between varieties and between years illustrates the need for forage testing when purchasing hay, even oat hay to feed dry cows. 62 KLAMATH EXPERIMENT STATION 1995

3 Table Oat Hay Variety Trial. Forage yield, dry matter, crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), and relative feed value (RFV) of oat varieties grown for hay at Klamath Experiment Station, OR, selection Dry Crude matter protein ADF NDF RFV ton/a Cayuse Border Ajay Magnum II Ab Rio Grande Monida Magnum B DU Magnum/Magnum II Otana Mean CV (%) LSD (0.05) KLAMATH EXPERIMENT STATION

4 Table Oat Hay Variety Trial. Forage yield, dry matter, harvest date in julian days (number of days after Jan. 1), crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), and relative feed value (RFV) of oat varieties grown for hay at Klamath Experiment Station, OR, Dry Harvest Crude Selection matter date protein ADF NDF RFV ton/a % Julian % % % Cayuse Border Ajay Magnum 2000 (Magnum II) Ab Rio Grande (81Ab5792) Monida Magnum Byrd (B-3) Dusky (DU-1) Otana Park Ogle Westford (Barley) Belford (Barley) WA (Barley) Mean CV (%) LSD (0.05) NS NS 64 KLAMATH EXPERIMENT STATION 1995

5 Table 3. Two-year Summary of Oat Hay Variety Trial Two-year summary of forage yield, crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), and relative feed value (RFV) of oat varieties grown for hay at Klamath Experiment Station, OR, 1994 and Selection Crude protein ADF NDF RFV ton/a % % % Cayuse Border Ajay Magnum 2000 (Magnum II) Ab Rio Grande (81Ab5792) Monida Magnum Byrd (B-3) Dusky (DU-1) Otana Mean CV (%) LSD (0.05) KLAMATH EXPERIMENT STATION