OBSERVATIONS ON YIELD TRIALS AND VARIETIES OF SPRING SOWN OATS IN RELATION TO DIFFERENT LEVELS OF PRODUCTIVITY IN WALES

Abstract

Summary.In former investigations certain varieties of oats were found to vary in order of yield, depending upon whether they were compared at centres of high or of low productivity.New data are presented in which the contrasting agronomic types Ceirch Llwyd, Radnorshire Sprig and Record were studied. These figures confirm the earlier investigations. The superiority of the higher tillering varieties was, however, maintained up to a higher level of yield than in the former studies, while that of Ceirch Llwyd at the lowest levels of yield was very marked.Yield data for a large number of trials conducted in certain counties in Wales are summarised. An analysis of these shows the same characteristic changes. Here Record gave a superiority of yield at the 23.0 cwt. level of 4.5 per cent, over the average yields of Radnorshire Sprig and Black Bell III. At the level of 16.8 cwt. it was itself surpassed by an equal margin by these varieties, the superiority of which increased to 11.4 per cent, at the 13.1 cwt. level and to 21.5 per cent, when the yield of Record was 9.7 cwt. In these data the accentuated superiority of Black Bell III over Record with each successive fall in the level of productivity was very pronounced.These data and others from soils of higher fertility are compared with the official estimated average yield of oats in Wales of 11.7 cwt. per acre. The lowness of the latter figure is discussed and considered in relation to the general problem of yield testing, the placement of varieties in order of merit of yield and other practical issues.A grouping'is given of the more commonly grown varieties of oats into three grades or groups in conformity with their suitability for soils of high, medium or low productivity. More data are needed in order to define more closely the limitations of the groups. The general insuffi‐ ciency of the data in this respect emphasises the necessity for a planned scheme of type trials (as distinct from the generally employed group testing of varieties) as a means of obtaining more precise information. In connection with trials at the lower levels of yield, their repetition with once, twice or even thrice grown seed is desired.The treatment of seed with mercuric dust compounds is briefly discussed in relation to oat growing on upland farms.A single year survey of the kind and proportion of oat varieties grown in Wales based upon certain sales of “seed” oats in 1933 showed that approximately 43 per cent, of the seed sold belonged to Grades II and III groups—mainly Grade II.Observations are made on the practical importance of, and priority values to be given to, straw stiffness, disease resistance, grain quality and time of maturity in relation to yield, and on the need for some agreed basis of evaluation.It is suggested that in consequence of the differential response of varieties and of the several factors which predetermine the value of a variety from place to place, increased attention should be given to testing of varieties in relation to locality and local requirements.