Factors Affecting Yield and Quality of Oats.

Abstract

Quality evaluation of oats relies primarily on hectolitre weight and, while it is an important characteristic, work carried out at Oak Park and elsewhere has shown that it does not accurately measure grain quality. Consequently, the selection of oat lots and varieties which have a high milling value has been limited, as present techniques fail to accurately determine the characteristics most closely related to milling quality. In this regard the kernel content and the ease of husk removal, termed the hullability, are the most important. This study has developed a new test for assessing oat kernel content, which is more rapid and cheaper than techniques currently available. Despite its obvious importance, oat hullability has not been assessed to date in quality evaluation due to the absence of a test procedure. However, this obstacle has now been overcome. The results of this work also provide a much better understanding of how hullability of individual varieties can be assessed, as well as investigating how this could be manipulated at field level. Using the methods developed, the selection of varieties with enhanced processing characteristics can now be carried out more precisely for Irish conditions. The field trials conducted to evaluate the effect of agronomic practices on quality indicated that the effect of factors such as nitrogen rate and seed rate was small in comparison to variety, which had the largest and most consistent effect. The variation in quality could not be completely explained by variation in the panicle characteristics studied. Increasing the nitrogen rate increased yield with the optimum being 160 kg N/ha in 1998 and 1999. However, lodging became a very significant factor at nitrogen rates above 100 kg N/ha in 1998, although it did not occur in 1999. This work supports the current Teagasc nitrogen recommendations for oats where levels of 110-140 kg N/ha (Soil Index 1) are advised.