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Tanner, D.G.

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Tanner
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D.G.
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Tanner, D.G.

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1995 - 19972
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Start date: 1990 × Keyword: Grain Yield ×

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Now showing 1 - 2 of 2
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    Improvement in yield of bread wheat cultivars released in Ethiopia from 1949 to 1987
    (African Crop Science Society, 1995) Tarekegne, A.T.; Tanner, D.G.; Getinet Gebeyehu
    Thirteen bread wheat ( Triticum aestivum check for this species in other resources L.) cultivars popular in the highlands of Ethiopia and representative of the period from 1949 to 1987 were studied for two cropping seasons in Ethiopia to estimate progress made in improving grain yield. The selected cultivars were grown with the effects of other genetic changes minimized by using fungicides to control foliar diseases, nets to prevent lodging, and periodic hand weeding to control weeds. Adequate levels of nutrients were also supplied. Significant differences were observed among cultivars for all crop parameters studied. The grain yield of bread wheat cultivars released since 1949 has increased at a mean rate of 77 kg ha-1yr-1 (2.21%) as measured in central Ethiopia and 50 Kg ha-1y-1(1.77%) under warmer and drier conditions in southeastern Ethiopia. Grain Yield was significantly and positively correlated with harvest index, grains m-2, spikelets spike-1 and grains spike-1. Genetic improvement has substantially increased the grain yield of rainfed bread wheat in the highlands of Ethiopia, resulting from an improved harvest index associated with an increased number of grains spike-1 and, as a result, grains m-2. Wheat breeders in Ethiopia should continue to emphasize spike fertility as a selection criterion for high grain yield.
    Publication
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    Grain yield of wheat as affected by cropping sequence and fertilizer application in Southeastern Ethiopia
    (African Crop Science Society, 1997) Asefa Taa; Tanner, D.G.; Kefyalew Girma; Amanuel Gorfu
    Cropping systems in the Ethiopian highlands consist primarily of cereals in rotation with grain legume and oilseed crops; the proportional allocation among crop species varies with altitude, rainfall, and soil type. Barley (Hordeum vulgare L.) tends to dominate in the highest altitudinal zones, while bread wheat (Triticum aestivum L.) is more common at medium altitudes on well-drained soils. A trial was established in 1992 at the Kulumsa and Asasa research sites in southeastern Ethiopia to evaluate interactions among wheat-based cropping sequences and annual applications of inorganic nitrogen (N) and phosphorus (P) fertiliser. Rotational crops included Ethiopian rapeseed (Brassica carinata L.), faba bean (Vicia faba L.), and barley. The results indicated significant rotational effects on wheat grain yield (GY), including enhanced GY in dicot vs. cereal rotations, in two year vs. three year rotations, in first year wheat after any break crop, and in rotation with faba bean vs. rapeseed. Interactions among cropping sequences and N and P fertiliser were also significant. Response to N was markedly reduced in two year rotations with any break crop, in first year wheat after any break crop, and after faba bean, in particular; this reflected higher soil N status in these cropping sequences. Conversely, P response was significantly enhanced in two year rotations and in the first wheat crop after any break crop, and in dicot-based rotations, particularly with faba bean. Presumably, this enhancement was the result of simultaneous improvement in soil N status and a reduction in wheat root pathogen and grass weed populations in these cropping sequences.
    Publication