Browsing by Author "Tryphone, G. M."

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Effect of tillage and weed control practices on weed density, cassava growth and yield at Mkuranga district, Tanzania
(East African Journal of Science, Technology and Innovation, 2023-09-14) Leonard, J. A.; Kudra, A. B.; Tryphone, G. M.
Poor and improper weeding in cassava production has been reported to cause cassava yield losses ranging from 40% to 90%. A study was carried out in 2019/2020 planting season at Kiimbwanindi village, Mkuranga, Tanzania to identify common weeds available in the selected cassava field and then the effect of different integrated weed control options was studied. Till only and till + Ridge, pre-emergence herbicides (Primagram Gold a.i 290 g/L S-metolachlor + 370 g/L atrazine and Oxfen a.i Oxyfluorfen 24% EC), post emergence herbicides (Force up a.i 480 g/L of Glyphosate-Isopropylamine salt) and back pack weeder with modified tines were tested on Cassava variety Kiroba in a factorial experiment arranged in a randomized complete block design (RCBD) replicated three times. Data on weed species, weed density, cassava height, girth and fresh root yield and soil were collected. By using Thomas methodology, perennial weeds Cyperus rotundus, Reissantia sp, Mucuna pruriens and Commelina benghalensis found to be the mostly and abundantly occurred weed species. The combination of tillage practices and pre-emergence herbicides application increased number of days’ weeds took to reemerge. The integrated weed control options significantly affected cassava fresh root weight and biomass, p = 0.019 and p = 0.026, respectively. The correlation analysis showed a non-significant positive relationship between cassava stem height and cassava fresh root weight (r = 0.389, p > 0.05), and cassava stem girth and cassava fresh root weight (r = 0.055, p > 0.05). The study concluded that, the combination of till + ridges, application of pre-emergence herbicide (S-metolachlor + atrazine) and post emergence herbicides (glyphosate) can effectively control weeds and provided favorable environment for cassava growth and root formation as compared to other treatment options.
Evaluating limitations of agroecological practices and stakeholders’ response: a Case of Uluguru mountains landscape in Morogoro municipality, Tanzania
(East African Journal of Science, Technology and Innovation, 2023-09-14) Tryphone, G. M.; Pastory, S. T.
In Sub-Saharan Africa, conventional farming is associated with intensive use of synthetic chemicals and inputs to maximize agricultural productivity. This is done at the expense of sustainable agroecologically based production systems. This objective was to describe limitations of agroecological practices and stakeholders’ response along Mountain Uluguru. The area has been vulnerable to unregulated land degradation aggravated by soil erosion largely due to unsuitable agricultural practices. The data were collected through questionnaires and in-depth interviews from 72 respondents who were purposively selected. Both qualitative and quantitative data were analysed using content analysis and statistical software respectively. Farmers undertake agriculture to increase production so as to meet food needs (44.8%) and employment opportunities (55.2%). About 41.7% of farmers who had land with secure tenure grew fruit and non-fruit trees on their farms or homesteads, 11.7% rented the farming land temporarily from owners through informal arrangements and the rest squatted on public land for cultivation of vegetables. From SWOT analysis, agroforestry is threatened by unregulated agricultural activities (18.6%) and overuse of forest resources unsustainably (7.0%). The agroecology training is not coordinated and supported by government agencies, which have authority to inform the policy makers about insecure land tenure and unavailability of organic inputs that would increase farmers’ livelihoods. Agro-soil erosion control and conservation agriculture measures are essential features of agroecology training, but some farmers were not aware of them and those who are aware do not adopt them effectively. The study concludes that, without the government acknowledgement of agro-ecology and its associated contributions there will always be weak institutional coordination among stakeholders required to regulate, promote and support agro-ecology practices to create a balance of conserved environment, protected ecology and enhanced farmers’ livelihoods. This is because there is no clear national guidelines and support (financial and technical) addressing the challenges facing agro-ecology practice yet.
Identification of genetic variability among Alectra vogelii strains from different geographical locations
(Journal of Current Opinion in Crop science, 2021-09-25) Reuben, F. M.; Kudra, A. B.; Tryphone, G. M.
Alectra vogelii threatens cowpea production in Sub-Saharan Africa. The weed complicates the development and operation of effective control tactics. For DNA extraction, young leaf samples of A. vogelii were taken directly from infested cowpea fields. The study used 23 SSR markers to determine genetic heterogeneity among A. vogelii populations, which will help design and implement effective breeding techniques and other parasite control approaches. The effective number of alleles was 1.5648, the observed number of alleles was 8, the anticipated heterozygosity was 0.648, and Shannon's Information index was 0.5169. PIC was 0.8301 on average. The Fst between populations was 0.2986, leaving 70.14 percent genetic variation within populations. A NTSYS -pc (UPGMA) dendrogram developed three clusters. More information on genetic heterogeneity among existing Alectra strains was gathered to help expand the cowpea gene pool for selection and creation of resistant genotypes.
Indirect selection for resistance to Alectra vogelii (benth) infestation in cowpea (Vigna unguiculata)
(International Journal of Environment, Agriculture and Biotechnology (IJEAB), 2017) Mbwando, A.; Lungu, D. M.; Tryphone, G. M.; Tembo, L.
Alectra vogelii (benth) is a parasitic weed which causes significant yield reductions in cowpeas (Vigna unguiculata Walp) in most of the sub-Saharan African countries. The objective of this study was to establish the effect of Alectra vogelii infestation on yield components of cowpea and the prospects of utilizing these components for indirect select to A. vogelii in resistance breeding. Seven genotypes of cowpea were crossed in all possible combinations without reciprocals and their 21 F2 progeny including parents were evaluated for reaction to Alectra vogelii infection at two locations, Ilonga and Hombolo. The experiments were laid using a Randomized Complete Block Design with three replications. Significant (P < 0.001) genotypic responses to Alectra emergency and infestation were found. A significance negative correlation was found between the Alectra emergency and infestation to yield and yield components (P< 0.01 and P< 0.001). However, both yield components (Number of pods per plant and 100 seed weight) tested exhibited a weak r2 value (< 0.25) implying that these components can only be used to supplement and not as a substitute to direct selection in breeding for resistance to A. vogelii.
Response of spodoptera frugiperda larval instars to commonly used insecticides in Tanzania
(Asian Plant Research Journal, 2022-12-24) Kiva, F. Mbemba; Tryphone, G. M.; Rwegasira, G. M.
Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a polyphagous migratory pest reported in Tanzania in 2017. Limited choices of officially registered insecticides for the control of the pest when it first occurred led to many farmers opting for the few available ones including those that were not registered for the pests. The current study drew from a survey conducted in 2018 that listed the insecticides commonly used by farmers against the pest. The study assessed the effectiveness of the insecticides against the different S. frugiperda larval instars under field conditions in the 2019 and 2020 growing seasons. Ten commonly used insecticides were applied to S. frugiperda damaged maize crops. Obtained results suggested a varied effectiveness of the tested insecticides with some inflicting significant (p < 0.001) mortality of S. frugiperda larvae while some proved ineffective. Ninja plus 5EC, Profecron 720 EC, Multi alpha plus 150 EC and Duduba 450 EC, caused highest mortality of S. frugiperda in all experimental plots accompanied with reduced incidences and damage severities on maize crops while Thunder 145 OD and Attakan 350 SC were the least effective. Yields obtained from the experiments suggested a significant impact of applied insecticides whereby plots treated with Duduba 450 EC produced the highest yield (4 tons/ha) compared to non-treated plots (2.2 tons/ha). The findings from this study prove that some insecticides were effective against the pest while some were not. As such farmers’ complaints on the ineffectiveness of traded insecticides could be real.