“An economic oat breeding program will only succeed in proportion to the breeder's skill and knowledge in being able to consider the project as a whole, rather than as separate entities” J.G. Carroll (1951)¹

This book describes the importance of the oat crop to sustainable farming and the pivotal role that oat breeders have in this. It describes the outcomes from the author’s contribution to the oat breeding program run by the New South Wales (NSW) Department of Agriculture from 1957 to 1974, including oat line and variety breeding and testing. The book covers the development of high yielding, dual-purpose grazing and grain oat varieties, and the methods used to breed and test these varieties, including trial results up to the present day. Some of this work was published in 1961, 1965, 1966, 1992 and in 2003.

Chapter One introduces the role that oats play as an important role in human and livestock nutrition, and as such, an understanding of the genetics of oats is significant in world agriculture and economics. Oats provides grain for humans and livestock, a grazing or forage crop for livestock, as well as the ability to provide combined grazing and grain production. While the significance of the oat grain in benefiting human health has received considerable attention in the past decade, relatively little attention has been given to this important attribute of combined grazing, grain production and total crop value in the research and extension literature. This reflects a lack of awareness of the full potential of the oat crop. Based on the recent findings of the Food and Agricultural organisation (FAO) studies, the world supply of agricultural produce is meeting the demands of the current world population. The total world production of cereals increased at an annual rate of 1.45% over the period of 1981-1990, while total meat production increased at an annual rate of 2.87%. These trends suggest that increased cereal crop yields have allowed for an increase in the area available for pasture and hence livestock production. Improving the total quantity and quality of world pasture production is therefore becoming increasingly important for meeting the corresponding increases in global food demands. The oat crop has a significant role to play in this increase in pasture production.

Chapter Two describes how oat breeding has led to the development of oat varieties for the 3 main climatic regions of Australia. These three climatic regions or zones also exist in the state of New South Wales (NSW). These three regions are as follows: The sub-tropical climate zone, also referred to as the summer rainfall zone, and also occurs on the coastal areas of Southern Queensland and Northern NSW (including Grafton, where a crown rust nursery is located). The uniform rainfall climate zone which covers the inland area of NSW from as north as Dubbo to Temora in southern NSW. The winter rainfall climate occurs south of Temora and includes the Australian states of Victoria, Tasmania, South Australia and Western Australia. An inventory of oat cultivars and their pedigrees is presented in relation to the climatic regions in which oats are grown in Australia. The inventory tables list the name or accessional line of the oats, their pedigrees and breeder. A description of the Australian oat ideotype is also proposed.

Chapter Three described the results of 34 years of oat breeding and testing of dual-purpose varieties (for grazing and grain recovery) by the NSW Department of Agriculture. A High-vigour cross (HvII 57-75) is identified which led to the release of Blackbutt (an F₄ directed bulk type) in 1975, and Carbeen (an F₆ plant progeny of the normal pedigree system) in 1981. This High-vigour cross also produced a number of high yielding F₄ directed bulk types and F₂ plant progenies bulked in the F₃ as a result of their relatively high phenotypic uniformity. The highest yielding F₃ bulk was numbered P4315, which although classed as an early oat, out-yielded all other varieties, including Blackbutt, for total biomass, following early sowings, and over a wide range of soils and climates and a great many seasons. The success of these oats was due to the Isolection plant breeding system pioneered by the Author at Glen Innes from 1957 to 1964. Other F₄ directed bulks were P4314 (high-yielding both as a winter oat and a spring oat at Glen Innes) and P4318, both of which had large grains and, together with Blackbutt and P4315, were significantly superior over 5 grazing cuts (including the mid-winter cut) to Coolabah and all other advanced lines submitted by plant breeders from Temora NSW, that were using conventional breeding methods during the same period. Selection of lines at the F₂ generation has been demonstrated as a simple way of forecasting wider adaptability of early generation material.

Chapter Four describes why Glen Innes, on the New England Tablelands in NSW, has proven to be the best centre for breeding oats for the heavy soils of the Riverina at Leeton, southwestern NSW. Plant selections made on the black self-mulching soils of the Glen Innes Research Station of northern NSW have resulted in the varieties Acacia, Bundy, and Mugga; all now replaced by Blackbutt. Both areas require resistance or tolerance to stem rust, water logging, red-legged earth mites, BYDV, lodging, shattering and second growth. Although frost damage is less of a problem in the irrigation areas than on the northern tablelands of NSW, the frost resistant bulks from the cross F.Ga x VRAF.VRSF demonstrated good tolerance to water logging on heavy soils. Blackbutt also excelled as both a dual-purpose and a grain only variety and is recommended for both northern and southern irrigation areas.

Chapter Five describes the important influence of the oat growing environment on oat grain quality. Oat grain quality (grain weights per 1000 seeds and groat percentages) was found to be an effective measure of the environmental stress imposed on an oat variety at a particular geographical and climatic centre. The results of various oat trials conducted across NSW show that the environment has an effect on the maturation and filling of the oat grain. The results compiled by the Author suggest that northern NSW (i.e. the summer rainfall zone) could be further sub-divided into 5 climatic regions, from east to west, for the purpose of recommending oat varieties. Glen Innes, at an elevation of 1,128m and latitude 29° 42” S. on the New England Tablelands, proved to be the ideal climate for developing high groat percentage and large grain size. A sixth climatic zone, located in Leeton, NSW (uniform rainfall zone), at elevation of 152m and latitude 34° 33” S., was the second most favourable centre, but required irrigation for full grain development.

Chapter Six discusses plant breeding methods and technologies and their potential for increasing oat crop yields and oat crop improvement. It specifically introduces the importance of hybrid vigour and a non-stress environment for higher percentage heritability selection and therefore providing a more productive conventional plant breeding method for the improvement of crops. This chapter draws together the results from trials presented in Chapters Three and Four to show the superiority of the Isolection method over the conventional oat breeding method for development of high yielding, multi-purpose oat varieties. GM technology and crops derived from cloning, a process devoid of hybrid vigour, are compared with proven plant breeding methods.

¹ From a NSW Department of Agriculture Internal Report. James Carroll was a plant breeder dedicated to oats, potatoes and gladioli.