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A soil surface under production gives a certain yield of a certain crop. In our modern society, any kind of industry must be efficient and has to give profits to its owner. Efficiency of the plant production industry varies greatly from year to year and from place to place. [...]

Lodging in small grains is often responsible for losses in crop yield and quality. Due to difficulties in employing modern harvesting practices, in lodged crops, the cost of production increases, both because of time lost and because of increased labour requirements. [...]

No description available.

No description available.

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No description available.

Barley (Hordeum vulgare L.) is the preferred cereal for malting. Its suitability for malting depends on many criteria, including the size, shape and uniformity of the kernels. Malting quality is affected by many quantitative trait loci (QTL). Such loci have been mapped using phenotypic and genotypic information on all members of mapping populations. It may also be possible to detect marker-QTL associations using selective genotyping, in which only the progeny with high or low phenotypic values for a trait are genotyped with available markers. Information on marker-QTL associations may be used in marker-assisted selection. Marker-assisted selection could be particularly useful for barley malting quality traits, some of which are costly to assess. Here, three studies were conducted related to QTL for barley grain and malt quality characteristics. In the first study, QTL were mapped using kernel size and shape data obtained by image analysis on samples from a two-rowed by six-rowed barley cross. QTL were detected near vrs1 on chromosome 2(2H) and near int-c on chromosome 4(4H). Some QTL affected the within-sample variability without affecting the mean of kernel characteristics. QTL alleles that made kernels larger and/or rounder also tended to improve malt quality. Those that increased the variability of kernel size were associated with poor malt quality. In the second study, marker genotype data and grain and malt quality phenotype data from three mapping populations were used to investigate the feasibility of selective genotyping for QTL mapping. Almost all previously mapped QTL were detected often with only 10% of the population genotyped. Additional, possibly spurious, QTL were detected in regions of the genome where no significant QTL had been mapped. The results indicated that simultaneous investigation of two or more traits by selective genotyping could be worthwhile. In the third study, Morex alleles at a QTL on chromosome 7(5H) affecting alpha-amylase activ

Spring barley (Hordeum vulgare L.) is an important cereal crop in Quebec, where it is used as a crop for swine and poultry. Since barley is a better source of energy than protein, a protein supplement must be added to the feed. Consequently, the production of barley with high protein concentration in the grain (GPC) is desirable. Studies on intensive cereal management (ICM) practices in other countries have shown that high yields can be combined with a high GPC. From 1987 to 1990 three field experiments were conducted to evaluate the effects of ICM on the yields and GPC of six-rowed spring barley in Quebec. Our results describe the effects of individual ICM components (N fertilizer application, fungicide, and plant growth regulator) on the development of yield components and on GPC. In general, N had little effect on main stem yield spike$ sp{-1}$ and on tiller spikes m$ sp{-2}$. Possibly, plant density or environmental conditions may have imposed greater limitations on yield rather than N. Nitrogen treatments increased GPC generally by increasing the amount of protein grain$ sp{-1}$. Nitrogen treatments which increased the amount of protein grain$ sp{-1}$ increased the lysine and cyst(e)ine concentrations of the grain but decreased their concentration in the grain protein. The plant growth regulator ethephon increased GPC by increasing the amount of protein grain$ sp{-1}$, by decreasing the nonprotein content grain$ sp{-1}$, or by altering final grain size distribution. Ethephon often had damaging effects on yield. Large genotypic variation was observed for GPC, but could not be related to genotypic differences in N harvest index, total N accumulation, protein yield or post-anthesis N uptake and assimilation. Grain yield was weakly correlated with GPC. Examination of the cultivars grown from 1910 to 1988 showed that increases in grain yield were accompanied by increases in harvest index, total dry matter, and lodging resistance. Plant height was reduced over tim