Oat Hay Variety Trial R.L. Dovel, J. Rainey, and G. Chilcote 1

Transcription

1 Oat Hay Variety Trial R.L. Dovel, J. Rainey, and G. Chilcote 1 Introduction 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. Oat hay variety trials were established at KES in 1994, 1995, and 1996 to provide growers with information needed to make variety selection decisions. Both forage yield and quality of commercially available oat varieties were examined. 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 April 20, 1994, May 23, 1995, and May 10, 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 P205, 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. Only one harvest was taken in 1996, on August 1. Prior to harvest, plots were trimmed to 17 feet long. The crop was harvested using a flail harvester with a threefoot 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 Trial variability was high in 1994, making variety separation difficult. The highest yielding variety, Magnum, was not significantly different from 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 early maturing 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. 1/ Associate Professor, Biological Sciences Research Technician III, and Research Technician, respectively, Klamath Experiment Station, Klamath Falls, OR. 150 Klamath Experiment Station

2 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 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 excellent choices for short-season cereal hay production. Forage yields were even lower in 1996 than in 1995, due to frost damage and uneven irrigation distribution (Table 3). Ensiler, a newly released forage variety, was the highest producer in Entries that were not significantly different from Ensiler include Byrd, 83Ab3250, Magnum 2000, and Border. Cayuse was the lowest producing entry in the trial in 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 1994 and Average crude protein concentration in the 1995 trial was 10.0 percent compared to 7.3 and 8.9 percent in 1994 and 1996, respectively. ADF, which is a predictor of forage digestibility, and thus animal performance, averaged 35.0 in 1995 compared to 41.3 and 38.5 in 1994 and 1995, indicating that feeding oat hay produced in the 1995 trial would result in the best animal performance (lower ADF values indicate higher quality). Minimum 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 all three 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 minimum 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. 151 Klamath Experiment Station

3 Table Oat Hay Variety Trial. Forage yield, dry matter, and forage quality of oat varieties grown at Klamath Experiment Station, Klamath Falls, OR, Selection Yield-- matter Protein ADF NDF RFV ton/a rank % % Cayuse Border Ajay Magnum Ab Rio Grande Monida Magnum Byrd (B-3) Dusky (DU-1) Magnum Otana Mean CV (%) LSD (0.05) Klamath Experiment Station

4 Table Oat Hay Variety Trial. Forage yield, thy matter, and forage quality of oat varieties grown at Klamath Experiment Station, Klamath Falls, OR, Selection Yield matter Protein ADF NDF RFV ton/a rank % % % % 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 NS Klamath Experiment Station 153

5 Table Oat Hay Variety Trial. Forage yield, dry matter, and forage quality of oat varieties grown at Klamath Experiment Station, Klamath Falls, OR, Selection Yield matter Protein ADF NDF RFV ton/a rank Cayuse Border Ajay Magnum 2000 (Magnum II) Ab Rio Grande (81Ab5792) Monida Magnum Byrd (B-3) Dusky (DU-1) Stampede Bay Ensiler Westford (Barley) Mean CV (%) LSD (0.05) NS Klamath Experiment Station