Evaluation of dual-purpose oat varieties, Glen Innes 2020

Abstract

Summary of results • Oat varieties Nile, Eurabbie and Dynasty demonstrated the greatest flexibility as ‘graze and grain’ options for growers. These varieties can achieve grazing at growth stage 30 (GS30) and grain at harvest in this environment. • For grain production sowing date 3 (SD3) in mid-April produced significantly higher yields than SD1 (5 March) for all varieties in both the grazed and ungrazed treatments. • Nile and Eurabbie, from the SD3 grazing treatments, produced the highest grain yields of 2.87 t/ha and 2.85 t/ha respectively. • Yiddah[PBR] and Bimbil had the lowest grain yield from SD1. • Grain quality was low for all varieties and treatment combinations due to frequent rainfall before harvest. • Simulated grazing at GS30, the optimal time for first grazing, resulted in a higher grain yield than most of the ungrazed treatments of the corresponding varieties. Early grazing is a useful management option to improve grain production from dual-purpose oat varieties in this environment as it reduces lodging in the crop, particularly in a high growth potential season such as 2020. • Varieties differed widely in the time taken to reach GS30 and the amount of biomass that they produced at this stage. • Dynasty, Nile and Bimbil were the fastest varieties (55 days) to reach GS30 for SD1, producing biomasses of 3.06 t/ha dry matter (DM), 2.52 t/ha DM and 2.44 t/ha DM respectively. • From SD1, Eurabbie produced the greatest amount of early biomass at GS30 of 4.1 t/ha DM, taking 69 days to reach this stage. • From SD2, Yiddah[PBR] and Nile produced the greatest amount of biomass at GS30, with 4.75 t/ha DM and 4.73 t/ha DM produced respectively in 99 days. • From SD3 Eurabbie and Nile produced the greatest amount of biomass at GS30 with 4.06 t/ha DM and 3.51 t/ha DM produced respectively, taking 106 days. • Dynasty had the greatest response to sowing date, scoring the lowest DM production at GS30 in the experiment from the later sowing dates: SD2 (1.52 t/ha DM) and SD3 (1.71 t/ha DM) and respectively, compared with DM production from SD1 of 3.06 t/ha. • A strong sowing date effect was also observed for Dynasty in relation to grain yield, which ranged from 0.42 t/ha (SD1 non-grazed) to 2.58 t/ha (SD3 grazed). • Dynasty produced the most biomass at GS65 from the SD3 ungrazed treatment (11.71 t/ha DM), however, it took two weeks longer to reach GS65 than all other varieties. Yiddah[PBR] (10.93 t/ha, SD2), Nile (10.81 t/ha DM, SD3), and Bimbil (10.80 t/ha DM, SD3) produced comparable DM at GS65, but required less time to achieve it than Dynasty. • Feed values at GS30 were within the recommended dietary ranges for most sheep and cattle. • Dynasty and Nile produced the highest forage quality at GS65 with Australian Fodder Industry Association (AFIA) Grades A1-B2 and A2-B2 respectively.