M.C. Therrien and C.A. Grant

Agriculture & Agri-Food Canada,

Research Centre, P.O. Box 1000 A,

Brandon, Manitoba R7A 5Y3;

E-mail:MTherrien@em.agr.ca

CGrant@em.agr.ca

It is generally known that malting quality in barley is strongly influenced by both genotype (cultivar) and environment. In recent years, a shift in land cultural management on the Canadian prairies, from conventional tillage to direct drill, has taken place and its effects (if any) on specific cultivar performance is poorly understood. Malting barley dominates the barley acreage in western Canada, yet we know very little about the potential impact on malting quality from direct seeding malting barley into standing stubble. We recently completed a series of experiments in an attempt to determine what effect, if any, direct drilling of malting barley would have on major malting quality traits.

Research trials were established at two sites in western Manitoba - a light-textured, drought-prone soil and a moderately heavy-textured, moist soil. Experimental protocol and design were previously described in Therrien and Grant (1998). Analysis of Variance (ANOVA) was performed for a Split-Plot Design, with four replicates, using the GLM procedure in SAS (SAS Institute, 1992). Tillage was the main effect, while barley genotypes were sub-plots. A 350 g sample of grain was obtained from each plot and analysed for alpha-amylase levels (AA), diastatic power (DP), and percent malt extract (MEX), according to the methods described in Bendelow (1977). A total of 240 plots were sampled from six genotypes with two tillage treatments, conventional tillage (CT) and direct drill (DD) at two sites in 1994 and 1995 and one site in 1996.

There were no significant tillage effects or genotype x tillage interactions for any of the malting quality traits tested. There were significant genotype effects for all three traits and AA and MEX were also significantly affected by environment. A wide range of malting quality was expected as the genotypes were deliberately chosen to form a wide genetic base for this study. This can be seen for each trait in Table 2, where genotype to genotype variation ranges up to 50% of the respective means. This is typical of the range of differences in malting quality seen amongst different genotypes (Flom et al. 1986). Significant environmental effects were also expected as the two sites were deliberately chosen to represent widely differing growing conditions. Also, year to year climatic variation, under prairie-parkland conditions, is subject to wide fluctuations, affecting all aspects of plant development. All three traits show a wide variation in values between sites, as well as between years (Table 1), indicating a large environmental effect. These findings agree with previous work (Flom et al., 1986; Cox and Sheldon, 1992).

Our study, therefore, indicates that malting quality is primarily influenced by genotype and environment, and not by tillage effects or their interaction with genotypes. The implications to plant breeders is that selection for improved malting quality need not necessarily consider simultaneous selection under multiple tillage systems. This would otherwise have resulted in considerable additional costs to plant breeding programs. The implication to producers is that relative malting quality performance of barley genotypes (cultivars) would remain the same whether in a conventional or reduced tillage system. This allows for increased flexibility in choice of cultivar to grow for malting purposes.

Bendelow, V.M. 1977. Malting quality selection methods in Canadian barley breeding programs. J. Am. Soc. Brew. Chem. 35:81-85

Cox, D.J. and Sheldon, D.R.. 1992. Genotype x Tillage interactions in hard red winter wheat quality evaluation. Agron. Journal 84:627-630.

Flom, D.G., Thill, D.C., and Callihan, RH.. 1986. Tillage effects on spring barley production. Res. Prog. Rep. West. Soc. Weed Sci. p. 198-199.

Therrien, M.C. and Grant, C.A. 1998. Effect of tiilage management on yield performance in barley. Can. J. Plant Sci. 78: 301-303.

SAS Institute, 1992. SAS Users Handbook. Statistics Vol. 2. Pp. 197-264.