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Frequently repeated control plots and the moving mean of adjacent plots were compared as methods of controlling error in single‐row plots of barley, Hordeum sativumJess. (H. vulgareL.) Adjustment by either technique was more effective for grain protein content than for grain yield. Covariance adjustment using either moving mean or control plots prevented overadjustment in several instances and was always more effective than percentage adjustment in reducing experimental error. Repeated control plots and moving means gave similar control of experimental error, but control plots had less practical application than moving means. A partially balanced lattice design accomplished superior control to both methods using percentage adjustment and similar control using covariance adjustment. In cases where the number of entries was too large to accommodate an incomplete block design, covariance adjustment using the moving mean would be advantageous.

Anthers of two six-row barley cultivars Diamond (a germination salt sensitive cultivar) and Men Yuan Liang Lan (a germination salt tolerant cultivar), and their F1 reciprocal crosses were cultured in liquid media containing 0, 0.4, 0.6, and 0.8% Na2SO4. A total of 138 green pollen plants were obtained: 7 from Na2SO4 media, 128 from Na2SO4 free medium. Seeds of two successive generations of 61 pollen plants were germinated in a series of Na2SO4 solution (0 to 5.5%). It was found that among 37 progenies from F1 pollen in Na2SO4 free medium, 11 were as sensitive as “Diamond”, 12 were intermediate to the two parents, 7 were equal to the salt tolerant parent and 7 were more tolerant to Na2SO4 than ‘Men Yuan Liang Lan’. Whereas, no progeny from F1 pollen in high salt media was as susceptible as the susceptible parent; 2 were intermediate, 2 were equal to the salt tolerant parent and 2 were more tolerant than the salt tolerant parent. The results indicate that culturing anthers in Na2SO4 media effectively eliminated salt susceptible progenies. All 16 microspore-derived lines of Diamond were as susceptible as ‘Diamond’ to Na2SO4. The 5 lines from ‘Men Yuan Liang Lan’ microspores were as resistant to Na2SO4 as ‘Men Yuan Liang Lan’. All of the lines breed-true. The results indicate that the lines exhibiting elevated levels of tolerance to salt probably resulted from recombination of genes rather than from spontaneous mutation.

The main objective of this study was to evaluate the possibilities of using morphological characters as selection criteria for yield improvement in barley (Hordeum vulgareL.). In order to obtain this information, the F1of seven‐cultivar diallel cross was grown in the field in 1969 and 1970 to study the inheritance of grain yield, tillers per plant, kernel weight, kernels per head, flag leaf area, erectophile flag leaf area, peduncle area, head area, flag leaf area duration, culm diameter, and flag leaf angle, The results indicate that both agronomic and morpho‐physiological traits were controlled mainly by additive gene action. Dominance effects were also observed, but these were not stable in controlling grain yield, kernel weight, and flag leaf angle. The photosynthetic areas above the flag leaf node, culm diameter, and flag leaf area duration appear to be controlled by partially recessive gene action. With the exception of flag leaf angle, all the morpho‐physiological traits were significantly associated with grain yield over two years of observation. Since selection for morpho‐physiological traits is easy and the heritabilities for these traits were quite high, genetic gains for these traits are expected. Consequently, selection for morpho‐physiological traits appears to be a promising means of establishing a high yielding plant type.

Selection for increased seed set was carried out in the segregating generations of four hybrid populations derived from intercrosses of five autotetraploid lines. The seed set of the early generations of the hybrid populations was higher than the respective parents and was maintained through the F5to F10generations. Selection, however, was ineffective in increasing the percentage seed set. The greater seed set of the hybrids was probably not due to heterosis unless a great deal of preferential pairing occurred. Selection was also carried out for reduced seed set and this was also ineffective. The lack of success in selection indicates a need to select on the basis of specific combining ability to improve the seed set of autotetraploid barleys.