VARIETAL DIFFERENCES IN BARLEYS AND MALTS: IV. COMMONLY MEASURED PROPERTIES AND THEIR CORRELATIONS WITH NITROGEN AND 1000-KERNEL WEIGHT

Samples representing 12 varieties of barley grown at 12 widely separated experimental stations in Canada were malted and subsequently analyzed. Varietal differences were found in steeping rate, malting loss, sprouts, extract, wort nitrogen and diastatic activity.O.A.C. 21 and Mensury, varieties which Canadian maltsters prefer, gave high values for all six properties. Olli, which maltsters consider promising, gave still higher values. Pontiac equalled O.A.C. 21 only in diastatic activity, and the remaining six-rowed, rough-awned variety, Peatland, which has proved less satisfactory, gave lower values for all properties, and this inferiority was more apparent when adjustments were made for its high nitrogen content. In general, the six-rowed, smooth-awned varieties, particularly Regal and Wisconsin 38, gave much lower values. However, Nobarb was only 1% lower in extract than O.A.C. 21, and Velvet equalled the latter in wort nitrogen and diastatic activity. The two-rowed varieties, Charlottetown 80, Hannchen and Victory, were higher in extract but lower in other malt properties than O.A.C. 21. Hannchen, of which considerable quantities are malted in the United States, proved most similar to O.A.C. 21.Amongst the inter-varietal correlations between malt properties and nitrogen content or 1000-kernel weight of the barley, only the partial correlations for diastatic activity and 1000-kernel weight, independent of nitrogen, proved significant (r = 0.609). Amongst the inter-station correlations, indicative of intra-varietal associations, those for nitrogen and extract (r = −0.957), nitrogen and diastatic activity (r = 0.962), and nitrogen and wort nitrogen (r = 0.764), surpassed the 1% level of significance; whereas those for nitrogen and steeping time (r = −0.637), nitrogen and malting loss (r = 0.694), and 1000-kernel weight and steeping time (r = 0.652), surpassed the 5% level. The inter-station multiple correlation coefficient for steeping time and nitrogen and 1000-kernel weight (R = 0.840) proved highly significant. The corresponding multiple correlation coefficient for extract was not significantly higher than the coefficient of correlation with nitrogen alone.