Mohammed Karrou - Academia.edu (original) (raw)

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Papers by Mohammed Karrou

Plant Breeding, 2008

To study barley adaptation and improvement in the Mediterranean basin, a collection of 188 entrie... more To study barley adaptation and improvement in the Mediterranean basin, a collection of 188 entries comprising landraces and old genotypes and current modern varieties from the Mediterranean basin and elsewhere was tested on moisture-contrasted environments in seven Mediterranean countries, during 2004 and 2005 harvest seasons. The experimental design consisted of an unreplicated trial for all entries, augmented by four repeated checks to which a partial replicate containing a quarter of the entries was added. Best Linear Unbiased Predictions (BLUPs) representing adjusted genotypic means were generated for individual trials using a mixed model. BLUPs were used for genotype by environment interaction analysis using main effect plus genotype by environment interaction (GGE) biplots of yield ranked data and for comparisons of landraces, old and modern genotypes using analysis of variance. Mean yields ranged from near crop failure to 6 t/ha. Local landraces were better adapted to environments yielding below 2 t/ha, thus breeding has mostly benefited environments yielding above 2 t/ha where modern genotypes out yielded landraces and old cultivars by 15%. Current barley selection is leading to specifically adapted genotypes.

CropSyst model was calibrated for wheat planted at three sites in Egypt, with three soil conditio... more CropSyst model was calibrated for wheat planted at three sites in Egypt, with three soil conditions (clayey, sandy and salt affected soil) and three different wheat cultivars, one in each site. In clayey soil, wheat cultivar Gemmiza 9 was planted on two raised bed lengths (25 and 50 m), at two raised bed widths (0.65 and 1.30 m) and under three nitrogen treatments (100, 85 and 75% of the recommended optimum dose). In the new land, wheat cultivar Giza 168 was planted under three irrigation amounts (125, 100 and 75 of ETc) and two nitrogen treatments (100 and 75% of the optimum dose). Whereas, in the salt affected soil, wheat cultivar Sakha 93 was planted on flat bed and two raised bed widths (100 and 130 cm) and two nitrogen fertilizer doses (75 and 100% of optimum dose). The results of the calibration indicated that the cultivar-specific parameters were different for the three wheat cultivars in each site. The calibration results also showed that CropSyst model predicted wheat grains and biological yield, as well as water consumptive use with high degree of accuracy for the three cultivars in the three sites, where RMSE was low and d was high. In the clay and sandy soil locations, the model was able to simulate the effect of the applied treatments on soil moisture depletion and drainage, as well as nitrogen uptake by the plants. Furthermore, in the salt affected soil, the model was capable of simulating salinity distribution after the second and the third irrigation. The results implied that the calibration of CropSyst under these practices could be very important for other researchers to build on and develop other management practices to increase irrigation water and land productivity.

Plant Breeding, 2008

To study barley adaptation and improvement in the Mediterranean basin, a collection of 188 entrie... more To study barley adaptation and improvement in the Mediterranean basin, a collection of 188 entries comprising landraces and old genotypes and current modern varieties from the Mediterranean basin and elsewhere was tested on moisture-contrasted environments in seven Mediterranean countries, during 2004 and 2005 harvest seasons. The experimental design consisted of an unreplicated trial for all entries, augmented by four repeated checks to which a partial replicate containing a quarter of the entries was added. Best Linear Unbiased Predictions (BLUPs) representing adjusted genotypic means were generated for individual trials using a mixed model. BLUPs were used for genotype by environment interaction analysis using main effect plus genotype by environment interaction (GGE) biplots of yield ranked data and for comparisons of landraces, old and modern genotypes using analysis of variance. Mean yields ranged from near crop failure to 6 t/ha. Local landraces were better adapted to environments yielding below 2 t/ha, thus breeding has mostly benefited environments yielding above 2 t/ha where modern genotypes out yielded landraces and old cultivars by 15%. Current barley selection is leading to specifically adapted genotypes.

CropSyst model was calibrated for wheat planted at three sites in Egypt, with three soil conditio... more CropSyst model was calibrated for wheat planted at three sites in Egypt, with three soil conditions (clayey, sandy and salt affected soil) and three different wheat cultivars, one in each site. In clayey soil, wheat cultivar Gemmiza 9 was planted on two raised bed lengths (25 and 50 m), at two raised bed widths (0.65 and 1.30 m) and under three nitrogen treatments (100, 85 and 75% of the recommended optimum dose). In the new land, wheat cultivar Giza 168 was planted under three irrigation amounts (125, 100 and 75 of ETc) and two nitrogen treatments (100 and 75% of the optimum dose). Whereas, in the salt affected soil, wheat cultivar Sakha 93 was planted on flat bed and two raised bed widths (100 and 130 cm) and two nitrogen fertilizer doses (75 and 100% of optimum dose). The results of the calibration indicated that the cultivar-specific parameters were different for the three wheat cultivars in each site. The calibration results also showed that CropSyst model predicted wheat grains and biological yield, as well as water consumptive use with high degree of accuracy for the three cultivars in the three sites, where RMSE was low and d was high. In the clay and sandy soil locations, the model was able to simulate the effect of the applied treatments on soil moisture depletion and drainage, as well as nitrogen uptake by the plants. Furthermore, in the salt affected soil, the model was capable of simulating salinity distribution after the second and the third irrigation. The results implied that the calibration of CropSyst under these practices could be very important for other researchers to build on and develop other management practices to increase irrigation water and land productivity.