Effect of environment on oat yield and grain quality

Abstract

In recent years, little agronomic research has been conducted in Australia on oats. With grain markets becoming more aware of quality traits much can be gained by understanding the response of individual cultivars to growing conditions. The commercial release of new oat cultivars identified the need to determine under what conditions the best yields and quality could be obtained for each cultivar. Nine cultivars were grown in 12 delayed sowing experiments in the wheatbelt region of Western Australia from 1997-2000. Traits assessed included grain yield and quality. Delayed sowing, reduced grain yield, seed weight and groat oil content. The yield efficiency of converting post sowing rainfall (PSRF) into yield (yield/PSRF) increased with delayed sowing. Delayed sowing also increased groat beta-glucan content and screenings below a 2.0mm screen but decreased groat percent for most cultivars. Whilst grain density and groat protein were not affected by delayed sowing. As PSRF declined, yield, seed weight, groat percent and groat oil were reduced. Grain density increased as PSRF declined for all cultivars except one. Lower PSRF also resulted in higher screenings, and slightly higher groat protein and beta-glucan content. At lower PSRF levels there was more variation in yield, grain density and screenings because the timing of rain events became more critical at lower rainfall. The difference in groat oil content between the cultivars was much larger than the effect of PSRF. In the two trials that were waterlogged, yield was reduced by approximately 1.5-1.8 t/ha, grain density was 4 kg/hL lower and protein was reduced by 2%. Under waterlogging oil content increased and yield efficiency decreased with delayed sowing. Where weed competition was observed, yields were reduced by 1.5 t/ha, seed weight by 3-9mg and groat percent by 2-3%. These findings will provide growers and industry with a greater understanding of environmental effects on oat yield and quality for oats generally and for specific cultivars.