Browsing by Author "Rwehumbiza, F. B. R."

Now showing 1 - 7 of 7
  • No Thumbnail Available
    Item
    Combining ability and heterosis of selected grain and forage dual purpose sorghum genotypes
    (Canadian Center of Science and Education) Chikuta, Sally; Odong, Thomas; Kabi, Fred; Rubaihayo, Patrick; BomBom, A.; Okori, P.; Gibson, P.; Rubaihayo, P.; Kiryowa, M.; Ddamulira, G.; Karuma, A. N.; Mtakwa, P. W.; Amuri, N.; Gachene, C. K. K.; Gicheru, Patrick; Mhike, X.; Tesfahun, Kassie Girma; Magorokosho, C.; Chikobvu, Shamiso; Msongaleli, B.; Rwehumbiza, F. B. R.; Tumbo, S. D.; Kihupi, N.
  • No Thumbnail Available
    Item
    Enhancing response farming for strategic and tactical management of risks of seasonal rainfall variability
    Admassu, H.; Mahoo, H. F.; Rwehumbiza, F. B. R.; Tumbo, S. D.; Mogaka, H.
  • No Thumbnail Available
    Item
    Integrated catchment characteristics, runoffwater reservoir capacities and irrigation - requirement for bean productivity
    Singa, D. D.; Tumbo, S. D.; Mahoo, H. F.; Rwehumbiza, F. B. R.; Lowole, M. W.
  • No Thumbnail Available
    Item
    Integrated catchment characteristics, runoffwater reservoir capacities and irrigation - requirement for bean productivity
    (2013) Singa, D. D.; Tumbo, S. D.; Mahoo, H. F.; Rwehumbiza, F. B. R.; Lowole, M. W.
    Crop production in semi-arid Sub-Saharan Africa (SSA) is limited by over-reliance on rainfall, which is erratic and inadequate. Rainwater conservation and irrigation are needed to avert drought effects and dry spells, and extend crop production activities to dry seasons. A study was conducted from 2011 to 2013 at Ukwe area in Malawi, to determine the size of seasonal open surface reservoir and crop field in relation to catchment characteristics among smallholder farming communities, using beans as a case study crop. There is positive linear relationship between seasonal harvested watershed runoff and rainfall (over 75%). Based on the catchment characteristics and crop water requirement, catchment/cultivated area ratio was 2.1. Harvested runoff water is linearly related to seasonal rainfall amount. About 6000 m3 of water was required to irrigate a hectare of beans. Total volume harvested was estimated to support six-fold the current field area at bean water productivity of 0.7 g L-1. It is possible to determine dry season bean water productivity based on integrated effects of catchment characteristics, runoff water reservoir capacities and irrigation water requirement.
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Investigation of sorghum yield response to variable and changing climatic conditions in semi-arid central Tanzania: Evaluating crop simulation model applications
    (2013) Msongaleli, B.; Rwehumbiza, F. B. R.; Tumbo, S. D.; Kihupi, N.
    Combination of global circulation models (GCMs), local-scale climate variability and crop simulation models were used to investigate rain-fed sorghum yield response under current and future climate in central Tanzania. Decision Support System for Agrotechnology Transfer (DSSAT) v.4.5 and Agricultural Production Systems Simulator (APSIM) v 7.4 were calibrated and evaluated to simulate sorghum (Sorghum Bicolor L. Moench) var. Tegemeo in 2050s compared to baseline. Simulated median yields from both crop models for the baseline (1980-2010) agree with the trend of yield over the years realistically. The models predicted yields of sorghum in the range from 818 to 930 kg ha-1 which are close to the current national average of 1000 kg ha-1. Simulations by both models using downscaled weather data from two GCMs (CCSM4 and CSIRO-MK3) under the Fifth Coupled Model Intercomparison Project (CMIP5) and Representative Concentration Pathway (RCP 4.5) by mid-century show a general increase in median sorghum yields. Median sorghum yields will increase by 1.1% - 7.0% under CCSM4 and by 4.0% - 12.5% under CSIRO-MK3. Simulations for both current and future periods were run based on the present technology, current varieties and current agronomy packages. This examination of impacts of climate change revealed that increase in sorghum yield will occur despite further projected declines or increase in rainfall and rise in temperature. Modifying management practices through adjustment of sowing dates and the choice of cultivars between improved and local are seemingly feasible options under future climate scenarios depending on the GCM and the direction of the management practice. Our simulation results show that current improved sorghum cultivars would be resilient to projected changes in climate by 2050s, hence bolstering the evidence of heat and drought tolerance in sorghum crop, thus justifying its precedence as an adaptation crop under climate change. We conclude that despite the uncertainty in projected climate scenarios, crop simulation models are useful tools for assessing possible impacts of climate change and management practices on sorghum.
  • No Thumbnail Available
    Item