The study was aimed to determine the responses of 9 commercial and local cassava varieties to M. tanajoa and the environment in two different seasons (2014/2015, wet and dry) in the lake Zone. This was laid out in a Split plot design with varieties as sub plots and locations as main plots. Three field trials were conducted at three different locations, Ukiruguru (Latitude 020 43.156’ S, Longitude 0330 01.431’ E and elevation of 4000 m above sea level) N’gombe (Latitude 020 45.743’ S, Longitude 0330 01.838’ E and elevation 3888 m above sea level) and Kishiri (Latitude 020 48.694’ S, Longitude 0330 22.161’ E and elevation 4023 m above sea level) villages of Kwimba and Misungwi districts of Mwanza, respectively. These were replicated three times making a total of twenty seven plots. The treatments were allocated to a plot size of 36 m2 with 1 m path (boarder) between plots and 2 m between blocks. One stem cutting (30 cm long) was planted at a spacing of 1x1 m within and between rows giving a total of 10,000 plant population ha-1. This was allowed under natural infestation by the mites. The results indicated that the mites population and damage generally varied significantly (P= 0.05) among varieties, sampling dates and locations. In general, Kwimba recorded the highest population number of M. tanajoa while Ukiruguru had the highest root yield and number. The study shows that Kyaka appeared to be tolerant/resistant to cassava green mite while Liongo Kwimba, Naliendele, Suma and Namikonga were found to be most susceptible, respectively. Therefore, cassava varietal resistance has a significant effect on the population dynamics and damage of M. tanajoa in the Lake Zone, Tanzania.
Here we present results of a study of floristic composition, carried out at the Barakat Area, Gazira State, Sudan. Plant specimens were collected randomly from different habitat during two field surveys. Samples were prepared and deposited in the Herbarium of Faculty of Science, University of Khartoum. We identified 127 species of angiosperm belonging to 43 botanical families. From these, 110 species were dicotyledons from 36 families; with Fabaceae, Euphorbiaceae, Mimosaceae, Convolvulaceae and Caesalpinaceae as the most richest-in- species families. Regarding the monocotyledons, there were found 17 plant species belonging to 7 families with Poaceae and Cyperaceae as the most representitive families. The less frequent families were: Polygonaceae, Aristolochiaceae, Vitaceae, Cleomaceae and Commelinaceae. Parasitic plant belonging to the families Loranthaceae and Scrophulariaceae were also recorded.
In summary the flora consisted of 26 trees, 15 shrubs, 81 herbs and 5 climbers. Euphorbia was the most common genus with 4 species followed by Acacia with 3 species. The cultivated species represented 21.3% of the total flora, while the indigenous flora represented 78.7%.
The vegetation of Barakat area can be described as dominated by: Acacia nubica Benth., Ziziphus spina-christi (L). Willd, Calotropis procera (Aiton) R.Br., Acacia nilotica (L.) Willd.exDelile. This study will contributes positively to regional florestic knowledge of the Sudan and stimulate further studies on the flora of Sudan.
The study was conducted to evaluate the response of hybrid maize towards zinc (Zn) and iron (Fe) fertilization applied both as soil and foliar application. It is a possible way to increase the zinc and iron concentration in maize grain by the application of Zn and Fe fertilizers. To verify the claim an experiment was conducted. Maize hybrid was selected and three levels of Zn & Fe (viz.10, 20 and 30 kg ha-1) were applied at the sowing time. The foliar appliance of zinc sulphate and iron sulphate at the rate of 0.1% Zn and Fe was applied. Nitrogen, Phosphorus and Potassium were applied at recommended levels. There was a control plot with no use of Zn and Fe. Maize crop was harvested, grains were separated. Maize grain yield was recorded and analyzed for their Zn and Fe content. The results indicated that maize grain yield and their Zn and Fe content responded positively towards Zn and Fe application applied as soil or foliar application. The 30 kg of Zn and Fe ha-1 gave highest grain yield (7.76 t ha-1) which is at par with 7.64 t ha-1 grain yield from the plots receiving 20 kg of Zn and Fe/ha. The foliar reliance of Zn and Fe application raised the grain Zn (31.8 mg kg-1) and Fe (153.8 mg kg-1) contents. This increase is 55% and 51.8% in case of Zn & Fe, respectively over control. It is concluded from the study that iron and zinc fertilization is an effective way to increase corn yield, their concentration in maize grain and finally to get better quality corn.
Maize is considered susceptible to drought stress, when occurs at flowering stage. Thus, the development of drought tolerant maize cultivars is of important priority for plant breeders. The objectives of the present study were: (i) to assess the effect of maize genotype (G), irrigation (I) regime and their interaction on agronomic and yield characters and (ii) to identify drought tolerant and high yielding genotypes under water stress conditions. Six divergent inbred lines in drought tolerance were crossed in a diallel fashion. Inbreds (6), F1's (15) and checks (2) were evaluated in the field for two seasons under two irrigation regimes, i.e. well watering (WW) and water stress (WS) via withholding the 4th and 5th irrigations to induce water stress at flowering stage. A split plot design in randomized complete blocks arrangement with three replications was used. Data analyzed across two seasons revealed that significant reduction in grain yield of maize (25.53%) due to water stress was accompanied with significant reductions in ears/plant (2.76%), 100-kernel weight (8.41%), rows/ear (4.23%), kernels/row (6.82%), kernels/plant (12.57%) and plant height (4.37%) and increases in days to silking (3.50%), anthesis silking interval (21.17%), barren stalks (26.18%) and leaf angle (9.41%). Interaction between genotypes and irrigation treatments was significant, indicating that selection is possible to be practiced under a specific irrigation treatment. Reduction in grain yield and its components due to water stress differed from genotype to genotype. The inbreds L20, L53 and Sk5, and the F1 crosses L20 × L53, L53 × Sk5 and L53× Sd7 were the most drought tolerant and highest yielders under WS and the WW environments. Mean grain yield/acre (GYPA) of drought tolerant (T) was greater than sensitive (S) inbreds and crosses by 170.18 and 54.73%, respectively under water stress (WS) conditions. Under water stress, T×T crosses were generally superior in most studied characters over T×S and S×S crosses, indicating that the most tolerant cross to water stress should include two tolerant parents and assures that water stress tolerance trait is quantitative in nature.
Accurate detection of plant pathogen precedes control. Misdiagnosis of diseases results in chemical waste, crop damage and ultimately income loss. Precision in pathogen detection has been made possible by advances in plant pathology, biotechnology and nanotechnology. For instance, PCR and fluorescent kits have been developed to detect diseases. On-farm utilisation of the aforementioned technologies has been limited by the expertise required and cost. Colorimetric nanoprobes have been applied in detection of water pathogens and heavy metals. This study entailed development of nylon-ferrous oxide chitosan-silica nanoprobe for Ralstonia solanacearum pathogen. Electrospun nanofibres were used as support for ferrous oxide chitosan immobilised silica nanocomposite (FeOCISNC) gel. The materials were selected due to their compatibility, large surface area for microbial adsorption and high affinity of iron by R. solanacearum bacteria. Optimisation experiments were carried out to determine the concentration of components and pH that yielded highest iron oxide nanoparticles (FeONPs). There was significantly high yield (P=.05) when a ratio of 2:3 (v/v) for green tea extract to iron chloride solution and a pH of 6 were used. Synthesised composites were characterised using X-ray powder difraction (XRD). The resulting nanomaterials had crystallite sizes of 3.96, 5.00 and 11.60 nm for FeONPs, FeOCISNC and nylon-FeOCISNC respectively. Detection of R. solanacearum was marked by colour change from grey to brown in the presence of the isolated pathogen. This was also corroborated by XRD characterisation; the nanoprobe adsorbed pathogen had a crystallite size of 14.75 nm. Additionally, the time required for optimal adsorption of FeOCISNC gel and pathogen suspension on the nylon nanofiber and nylon-FeOCISNC probe respectively was determined using optical density (O.D) of the suspensions after adsorption. There was no significant difference (P=.05) in the O.D of FeOCISNC gel when nylon nanofibres were immersed for 8 hr, 16 and 48 hr. Also, the O.D of the pathogen suspension was not significantly different (P=.05) after 5, 30 and 60 min which validated the observation that the change in colour intensity from grey to brown on the nanoprobe was not visually different within the time period. The colour change was attributed to the disruption of the pathogen membrane by glucosamine units in chitosan followed by complexation, absorption and reduction of iron oxide. Absorption of iron from the nanocomposite was due to the high affinity for iron by the bacteria. It can be concluded that, the combination of ferrous oxide and chitosan silica nanocomposites gel produced a rapid, precise and user friendly tool for detection of the lethal pathogen. The precise detection will consequently form the basis for the pathogen control.