68 research outputs found
Effects of Reward Systems on Performance of Construction Workers in Ghana
One major problem facing organizational managers all over the world and in all sectors of every economy, be they private or public, is how to obtain optimum performance from employees. This is possible when an employee on individual and/or group level is highly recognized and rewarded for performance. It is therefore relevant to explore the effects of reward systems on the performance of construction workers in Ghana. This is what has been done and reported in this paper. Contractors with D1K1 classification, working or undertaking projects in the Northern part of Ghana and had elaborate and distinct system of rewarding employees were involved in the survey. A combination of interview and questionnaire administration was used to gather data. Respondents were chosen, based on their level of exposure to site administration of construction projects, and involvement] of the construction project. Through hypothesis testing, the Pearson chi-square results indicate a significant positive association between reward systems and performance with asymptotic significance level of less than 0.05. The findings indicate non-financial rewards were as important as financial rewards to improve the performance of employees. This paper recommends a multiple function and integration of framework which seeks to attract, retain and motivate employees to induce higher performance. Keywords: financial rewards, non-financial rewards, performance, construction industry
Yield gains in extra-early maize cultivars of three breeding eras under multiple environments
Open Access JournalAvailability of extra-early maize cultivars has facilitated the expansion of maize production into savannas of West and Central Africa (WCA). Fifty-six extra-early maize cultivars of three breeding eras;1995 to 2000, 2001 to 2006, and 2007 to 2012 were evaluated for 2 yr under 24 multiple-stress and 28 non-stress environments in WCA. Objectives of the study were to determine genetic improvement in grain yield of cultivars developed during the breeding eras, and identify high-yielding and s multiple-stress and non-stress environments. Yield gains from era 1 to era 3 under multiple stresses was associated with increased days to anthesis, reduced stalk lodging, and improved husk cover. Cultivars 2004 TZEE-Y Pop STR C4, TZEE-W Pop STR QPM C0, and TZEE-W Pop STR BC2 C0 of era 2; and TZEE-W STR 107 BC1, TZEE-W Pop STR C5, and 2012 TZEE-Y DT STR C5 of era 3 were high-yielding and stable across multiple-stress environments while 98 Syn EE-W from era 1, FERKE TZEE-W STR, TZEE-W Pop STR C3, and TZEE-Y Pop STR QPM C0 from era 2, and TZEE-W Pop STR C5, 2009 TZEE-OR2 STR QPM, 2009 TZEE-W STR, TZEE-Y STR 106, and TZEE-W DT C0 STR C5 from era 3 were outstanding across non-stress environments and should be tested extensively and commercialized. Considerable improvement has been made in breeding for multiple-stress tolerant extra-early maize cultivars
Low Cost Constant â Head Drip Irrigation Emitter for Climate Change Adaptation in Nigeria: Engineering Design and Calibration
A low cost constant â head emitter for drip irrigation was developed using cheap and readily available materials as a substitute for the imported drip emitters which deter the adoption of drip irrigation in sub â Saharan Africa (SSA). The emitter was calibrated at both laboratory scale and on the field. The drip system comprises of abarrel, sub-main line, lateral lines, tubes and emitters, it can irrigate140 crop stands and can be extended to 560 stands. The emitters produced a mean discharge and emission uniformity (Eu) of 1.60l/hr. and 74 % respectively; while the calibrated manufacturerâs coefficient of variation and distribution uniformity of discharge were 0.098 and 86.3% respectively. The system operates under low pressure (87.9 mbar) and can deliver the daily crop water requirement of a crop like maize in 20 minutes; the overall system performance based on field calibration is generally satisfactory and show potential for improvement when compared with global standards for drip systems. The systemâs low cost of N15, 870 ($79) gives it an edge over existing locally developed drip systems, the low technology and the use of locally available materials coupled with the water savings will enable famers to adapt to the impact of climate change in sub-Saharan Africa through the production of high value crops in the dry season.http://dx.doi.org/10.4314/njt.v34i4.3
Assessment of early-maturing maize hybrids and testing sites using GGE biplot analysis
Article Purchased; Published: 7 Sept. 2017Identification of outstanding maize (Zea mays L.) hybrids for target environments is complicated by genotype Ă environment interactions. Thirty-two early-maturity maize hybrids were evaluated at eight locations in Nigeria and six locations in Ghana for 2 yr to (i) identify high-yielding, stable hybrids across locations and/or hybrids specifically adapted to different locations, and (ii) identify ideal test sites for selection of superior hybrids in the two countries. Genotype, country, year, location (country), and their interactive effects were significant (P < 0·01) for grain yield, days to anthesis and silking, anthesis-silking interval, plant and ear aspects, and ears per plant. Mean grain yield of the hybrids ranged from 3177 kg haâ1 for EWH-5 to 4596 kg haâ1 for EWH-29. The genotype main effects plus genotype Ă environment interaction (GGE) biplot analysis revealed that EWH-29, EWH-8, and EWH-30 did not differ significantly in grain yield and were the most stable hybrids in both countries, whereas EWH-26 and EWH-32 were the most stable hybrids only in Ghana. The GGE biplot analysis identified Samaru, Kafin Soli, and Minjibir in Nigeria and Nyankpala, Damongo, and Fumesua in Ghana as the most discriminating locations. Minjibir (Nigeria) and Nyankpala (Ghana), being most discriminating and representative locations, were considered the ideal testing sites for the respective countries. The type of cultivars evaluated determined the most suitable locations for multilocation testing within Ghana and Nigeria. Whereas hybrids EWH-29, EWH-8, and EWH-30 should be suitable for production in Nigeria, EWH-26 and EWH-32 should be promoted for production in Ghana
Gains in grain yield of extra-early maize during three breeding periods under drought and rain-fed conditions
Open Access Article; Published online: 30 Aug 2018Drought is a key maize (Zea mays L.) production constraint in sub-Saharan Africa. Fourteen, fifteen, and twenty-five extra-early maturing maize cultivars, with varying Striga resistance and drought and low soil N tolerance, were developed from 1995 to 2000 (Period 1), 2001 to 2006 (Period 2), and 2007 to 2012 (Period 3), respectively. The objectives of this study were to examine yield gains in the cultivars and to investigate inter-trait relationships and yield stability under six drought and 17 rainfed conditions in West Africa from 2013 to 2016. Annual rate of yield increase across cultivars was 0.034 (3.28%) and 0.068 Mg haâ1 (2.25%), whereas yield gains per period were 0.17 and 0.38 Mg haâ1 under drought and rainfed environments, respectively. Yield gains under drought and rainfed environments were related to prolonged flowering period, increased plant and ear heights, improved stalk lodging, and ear and plant aspects, whereas delayed leaf senescence and increased number of ears per plant accompanied yield improvement under drought only. Ear aspect and number of ears per plant were primary contributors to yield and could be used as selection criteria for yield enhancement under drought and rainfed conditions. High-yielding and stable cultivars across all environments based on additive main effects and multiplicative interaction (AMMI) biplot included â2004 TZEE-Y Pop STR C4â and âTZEE-W Pop STR BC2 C0â of Period 2 and â2009 TZEE-W STRâ, âTZEE-Y STR 106â, âTZEE-W STR 107â, and âTZEE-W DT C0 STR C5â of Period 3. These cultivars could be commercialized to improve food self-sufficiency in sub-Saharan Africa
Genetic studies of extra-early provitamin-A maize inbred lines and their hybrids in multiple environments
Open Access Article; Published online: 25 Sept 2019Vitamin A deficiency, drought, low soil nitrogen (low N) and Striga hermonthica parasitism of maize (Zea mays L.) cause malnutrition and food insecurity in sub-Saharan Africa. The objectives of this study were to determine combining abilities of extra-early provitamin A (PVA) lines, classify them into heterotic groups (HGs), identify testers, and determine yield stability of hybrids under contrasting environments in two trials. In trial 1, 20 extra-early PVA lines were inter-mated in a diallel mating scheme to obtain 190 F1 hybrids. The 190 F1 hybrids plus six checks were tested under Striga infestation, drought, and stress-free environments in Nigeria from 2015 to 2017. In trial 2, 35 extra-early yellow hybrids were evaluated under low-N, Striga-infested and stress-free environments in 2018. Provitamin A concentrations of 23.98 and 22.56 ÎŒg g-1 were obtained for TZEEIOR 202 and TZEEIOR 205. TZEEIOR 197 Ă TZEEIOR 205 (20.1 ÎŒg g-1) and TZEEIOR 202 Ă TZEEIOR 205 (22.7 ÎŒg g-1) contained about double the PVA level of the commercial check, TZEEI 58 Ă TZEE-Y Pop STR C5 (11.4 ÎŒgg-1). Both general (GCA) and specific (SCA) combining ability variances were statistically significant for most agronomic traits, although GCA was much larger than SCA effects, indicating that additive genetic effects primarily controlled the inheritance of those traits. TZEEIOR 97 and TZEEIOR 197 were identified as inbred testers. TZEEIOR 197 Ă TZEEIOR205 (20.1 ÎŒg g-1) was identified as a single-cross tester as well as the most stable and highest-yielding hybrid across environments. TZEEIOR 202 and TZEEIOR 205 should be invaluable resources for breeding for high PVA. PVA level was independent of hybrid yield potential, indicating that selection of superior hybrids with elevated PVA levels should be feasible
Use of GGE biplot for targeting early maturing maize cultivars to mega-environments in West Africa
Maize (Zea mays L.) is an important staple food consumed by people with
varying food preferences and socio-economic backgrounds in West Africa
(WA). Genotype by environment interactions (G
7E) exist in WA
implying the need for extensive testing of cultivars in multiple
environments over years before cultivar realistic recommendations can
be made. This study examined the effect of G
7E on the performance
and stability of early cultivars and to identify core test locations in
the mega-environments of WA. Across locations, 2004 TZE-W Pop STR C4
produced the highest grain yield and was the most stable cultivar.
DMR-ESRW QPM produced the lowest yield. The test environments
contributed about 83.4% of the total variation in grain yield, while
genotypes accounted for 1.5% and G
7 E, 11%. Test environments
were classified into four mega-environments, namely, Katibougou,
Sotouboua, Ejura, and Bagou as the first group; the second group
consisted of Manga, Nyankpala, Bagauda, Yendi, Angaredebou, Mokwa,
Katibougou, and Zaria; while the third group comprise of Ativeme, and
Ikenne; and the fourth, Ina. Test locations Ejura, Sotouboua and Bagou
and Katibougou were highly correlated in their ranking of the genotypes
in group 1, suggesting that a promising early maturing cultivar
selected in one of these locations in one country will also be suitable
for production in the other locations within the same mega-environments
in different countries. Kita was identified as the ideal location,
while Zaria was close to the ideal location.Le ma\uefs (Zea mays L.) est une nourriture principale consomm\ue9
par des personnes \ue0 pr\ue9f\ue9rence alimentaires et un
pass\ue9 socio-\ue9conomique vari\ue9s en Afrique de l'Ouest. Une
interaction G\ue9notype et Environnement (G
7E) \ue9tait
trouv\ue9e, impliquant ainsi le besoin en test extensive des
cultivars sur plusieurs ann\ue9es avant toute recommandation. Le but
de cette \ue9tude \ue9tait d'examiner l'effet G
7E sur la
performance et la stabilit\ue9 des cultivars pr\ue9coces, ainsi que
d'identifier le test principal de milieu dans les
m\ue9ga-environnements de l'Afrique de l'Ouest. A travers les
milieux, 2004 TZE-W Pop STR C4 avait produit le rendement en grain le
plus \ue9lev\ue9 et \ue9tait le cultivar le plus stable. DMR-ESRW
QPM avait induit le rendement le moins \ue9lev\ue9. La contribution
du test d'environnements \ue9tait d'environ 83.4% de la variation
totale du rendement en grain, pendant que les g\ue9notypes et G
7 E pr\ue9sentaient 1.5% et 11%, respectivement. Les tests
d'environnements \ue9taient classifi\ue9s en quatre
m\ue9ga-environnements \ue0 savoir, Katibougou, Sotouboua, Ejura,
and Bagou comme premier groupe; Manga, Nyankpala, Bagauda, Yendi,
Angaredebou, Mokwa, Katibougou, and Zaria comme deuxi\ue8me groupe,
alors que le troisi\ue8me groupe comprenait Ativeme, et Ikenne et le
quatri\ue8me, Ina. Le test de milieux Ejura, Sotouboua, Bagou et
Katibougou \ue9taitent hautement corr\ue9l\ue9 sur le plan
ranking des g\ue9notypes au sein du groupe 1, sugg\ue9rant qu'un
cultivar pr\ue9coce promettant s\ue9lectionn\ue9 dans un de ces
milieux dans un pays sera appropri\ue9 pour la production dans
d'autres milieux au sein des m\ueames m\ue9ga-envoronnements dans
diff\ue9rents pays. Kita \ue9tait identifi\ue9 comme un milieu
ideal, alors que Zaria \ue9tait proche du milieu ideal
Application of the Hybrid-Maize model for limits to maize productivity analysis in a semiarid environment
Effects of meteorological variables on crop production can be evaluated using various models. We have evaluated the ability of the Hybrid-Maize model to simulate growth, development and grain yield of maize (Zea mays L.) cultivated on the Loess Plateau, China, and applied it to assess effects of meteorological variations on the performance of maize under rain-fed and irrigated conditions. The model was calibrated and evaluated with data obtained from field experiments performed in 2007 and 2008, then applied to yield determinants using daily weather data for 2005-2009, in simulations under both rain-fed and irrigated conditions. The model accurately simulated Leaf Area Index , biomass, and soil water data from the field experiments in both years, with normalized percentage root mean square errors < 25 %. Gr.Y and yield components were also accurately simulated, with prediction deviations ranging from -2.3 % to 22.0 % for both years. According to the simulations, the maize potential productivity averaged 9.7 t ha-1 under rain-fed conditions and 11.53 t ha-1 under irrigated conditions, and the average rain-fed yield was 1.83 t ha-1 less than the average potential yield with irrigation. Soil moisture status analysis demonstrated that substantial potential yield may have been lost due to water stress under rain-fed conditions
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