Ephrat, J., The Volcani Institute of Agricultural Research, Bet Dagan, Israel
Lachover, D., The Volcani Institute of Agricultural Research, Bet Dagan, Israel

Different characteristics of barley grains: 1000-kernel weight, "Vollgerste", crude protein content (N×6.25), insoluble carbohydrate and hull percentages were tested on samples taken from seven variety trials and from nursery plots of breeding lines of a Proctor x Brandon cross. Coefficients of correlation between these grain traits and extract percentages were calculated. Hull percentage and insoluble carbohydrate content were closely correlated: they had a very strong depressing effect on extract percentage. The effect of crude protein on extract percentages was also depressing; however, the coefficients of correlation were significant only within variety types (rigidum or tenerum). The following extract formula, based on hull percentage (H) and nitrogen content (N), is proposed: E (extract percentage)=101.9-5.5 N-1.6 H or: E=101.9-0.88 P (protein %)-1.6 H Mean values of predicted extract were very close to mean values of extract percentages found by the standard EBC-method. Coefficients of correlation between predicted and EBC-extract percentages were very high all in groups of samples (r=0.914** to 0.982**). © 1969 Kluwer Academic Publishers.