Selection Strategies for Breeding Dual-Purpose Cultivars of Oats and Triticale

Research Supervisors:
Professor Ted Wolfe and Mr Glenn Roberts (NSW Agriculture)

Research Staff:
Mrs Kamrun Nahar (PhD student)

Funding:
$88,130 (GRDC)

Duration:
1998-2001

Project Summary:
Oats ( Avena sativa) has been a significant component of agriculture in Australia, especially in NSW, as a dual-purpose (grazing and grain) crop. One reason for its popularity was the role that oats has played in crop rotations to control take-all disease (Gaeumannomyces graminis), to which wheat and barley are susceptible. Another reason for its popularity, particularly in NSW, was the range of cultivars that could be sown as early as February, grazed during the feed gap in early winter and left to recover for grain. However, over the last 25 years there has been a growing decline in the popularity of oats such that in 1995 the total area under oats in Australia was 1.035 m ha compared to a total area of
Dual purpose oats and triticale cultivars for forage production.
Tillering production stage.

1.600 m ha in 1970. A number of factors could be linked to this decline, including competition from dual-purpose cultivars of wheat and barley, the success of canola which has taken over from oats the role of a break crop in crop rotations, and the failure of oat breeders to produce dual-purpose cultivars that rival the grain yield of grain-only cultivars.

It is in the interests of farmers to reconsider oats as a viable crop.
Another feed grain with potential is triticale ( Tritico secale) which to date has been a cereal crop of minor importance. Compared to oats and wheat, triticale is more tolerant of acid soils and cold temperatures. Interest in using triticale has expanded in Australia from 24,000 ha in 1980 to 75,000 ha in 1995.

The focus of this project is on improving oat and triticale cultivars as dual-purpose crops. The particular objectives are to :

(i) investigate possible strategies for improving early forage production by studying the effects of agronomy factors (seeding rate, time of sowing), winter growth habit (prostrate or erect) and the dwarfing gene on early forage production. Selection techniques for screening early vigour genotypes from the breeding population will be evaluated.

(ii) assess the effect of a range of defoliation/grazing strategies on grain yield, quality and harvestability of dual-purpose oats and triticale, in order to design efficient and appropriate selection strategies. Previous research indicated that there is an important interaction between the defoliation /grazing regimes and the ranking of dual-purpose cultivars for grain yield.

(iii) conduct experiments to study the heritability and genetic variation of the physical qualities of oats and triticale grain in selecting for improved grain quality in dual-purpose cultivars.

In 1998, a field experiment (at NSW Agriculture, Temora) and a growth-house experiment (at CSU, Wagga) were conducted to evaluate the pattern of early dry matter production of representative oat and triticale cultivars. In the field experiment, six cultivars (four oats, two triticales) were evaluated at the three seeding rates (50, 100 and 200kg/ha). In the growth-house experiment, four cultivars (two oats, two triticales) were compared at three densities and over two sowing times. The results showed that neither winter growth habit nor the dwarfing genes were important for early forage production. Early forage production was more affected by agronomic factors (seeding rate, sowing time) than by plant genotype. Therefore, it may be concluded that breeders of dual-purpose cereals could place less emphasis on selection for early dry matter production.