Welcome to SUAIRE

Sokoine University of Agriculture  Institutional Repository (SUA IR). This repository was built and is maintained by the university library  (Sokoine National Agricultural Library-SNAL) , in order to collect, preserve and disseminate scholarly output generated by University research community (staff and students) members.

This repository hosts a variety of openly accessible materials including: scholarly articles and books, theses and dissertations, conference proceedings and technical reports. For assistance about depositing your research output in the repository click here. SUA IR Policy  click here or any queries contact us at snal@sua.ac.tz.

Photo by @Sokoine University of Agriculture
 

Communities in SUAIRE

Select a community to browse its collections.

Now showing 1 - 5 of 14

Recent Submissions

Thumbnail Image
Item
Effects of rate and time of nitrogen application on growth, leaf nutrient contents and yield of sugarcane at Kilombero Sugar Estates
(Sokoine University of Agriculture, 1985) Mkelenda, Abdallah Salum
ABSTRACT A field study on the effects of rate and time of nitrogen fertilization on growth, leaf nutrient contents and yield of sugarcane (Saccharum officinarum) variety N. Co.376 was conducted at Kilombero Sugar Estates in Morogoro region during the 198?/83 cropping season*Four rates of N and three different times of application were tested in factorial combination in a randomized block design using a plantcane crop*The IT rates were 0, 100, 200 and 300 kg 10xa applied as ammonium sulphate * The times of application were (i) all the N applied at planting, (ii) all the N applied at three months, and (ill) N applied in two split doses: one half at planting, and the rest at three monthd* The crop was grown for twelve months.The germination, stalk population counts, and the heights of the plants were determined.The N, 2?, K, Ca and Mg nutrition of the crop were assessed by analysing cane leaves sampled from two—and four-montha old plants* The yield and quality of the crop were determined at harvest time.The germination was good and was not affected by the treatments* Nitrogen fertilization increased stalk population, and cane growth significantly. Nitrogen application increased the concentration of N in the leaves sampled at the two ages, For the two months samples the leaf N concentration ranged from 1.87% to 2.29%, while for the four months samples the concentration ranged from 1,38% to 1.94%. Leaf N concentrations in the four months old plants were highly correlated with sucrose contents in the plants,. cane yield, and sugar yield. suggesting that leaf IT concentration could be used in predicting these parameters. Using a curvelinear relationship between leaf IT concentration and sugar yield a tentative critical N concentration of 1,78% was established.The concentrations of P, K, Ca, and Mg were considered to be within the adequate range for the crop. All rates of IT increased cane yield significantly but sugar yield increased with increase in applied N only up to 100 kg N/ha, Further increase in N did not cause further increase in sugar yield:'mainly because of the negative effect of higher rates of N on sucrose accumulation in cane plants. In addition, nitrogen application reduced the quality of the juice; i.e. the brix, pol and juice purity.Time of application did not have any significant effect on any of these parameters.The results of the study suggest that the optimum rate of IT for sugar production in Ruaha area of Msolwa Estate is around 100 kg 10ia and that all the IT can be applied in the furrows at planting. Also leaf analysis technique can be used for assessing the sufficiency of IT in cane plants.
Thumbnail Image
Item
Auger metering studies for fine prilled URSA
(Sokoine University of Agriculture, 1988) Mwombeki, Francis Fabian
ABSTRACT Tne performance of sheet ana 'wire au6ers was studied for meterin6 prilleu urea fertilizer. First the physical characteristics of prilled urea was established. It was found that the angle of repose and the coefficient of fricition on galvanized steel surface increased with increased moisture content.The opening of the hopper bottom, inclination of hooper walls and modes of agitation were studied for uiiximizing fertilizer flow into the metering chamber. A bottom opening width of jO mm, hopper wall angle of 60 o with the horizontal and a rotary or eliptical agitation modes aere founu to provide optimum flow.Succeeding experiments were conducted to study the rate and consistency of fertilizer metering by sheet and wire auoer unaer varying pitch/diameter ratio,delivery tube in .ination, au6er speed and fertilizer moisture.Rate of fertilizer injection into flooded soils was studied under simuxared field conditions. Assessment was also made of the amount of r.-rti 1 i zer adhering to the augers during metering. A pitch diameter ratio of 1.25 give a maximum found to diecharge. Also, fertilizer discharge increased with greater inclination of the delivery tube and decreased with increasing fertilizer moisture contents.The metering accuracy generally decreased with greater inclination of the delivery tube fertilizer granule size decreased metering accuracy.The experiments, of injecting fertilizer in flooded soils were conducted in a rotating soil bin to simulate actual field conditions.The inclination of the delivery tube along the direction of the bin movement gave a higher injection rate than an inclination against the bin movement. The wire auger exhibited a greater injection capability than the sheet auger and produced higher pressure at the tube opening.This auger also encountered less sticking of fertilizer on the flight than the sheet auger.
Thumbnail Image
Item
Susceptibility of campylobacter strains to selected natural products and frontline antibiotics
(MDPI, 2020) Gahamanyi, Noel; Song, Dae-Geun; Hyun Cha, Kwang; Yoon, Kye-Yoon; Leonard E.; Mboera, G.; Matee, Mecky I.; Mutangana, Dieudonné; Amachawadi, Raghavendra G.; Komba, Erick V. G.; Pan, Cheol-Ho
Campylobacter species have developed resistance to existing antibiotics. The development of alternative therapies is, therefore, a necessity. This study evaluates the susceptibility of Campylobacter strains to selected natural products (NPs) and frontline antibiotics. Two C. jejuni strains (ATCC® 33560TM and MT947450) and two C. coli strains (ATCC® 33559TM and MT947451) were used. The antimicrobial potential of the NPs, including plant extracts, essential oils, and pure phytochemicals, was evaluated by broth microdilution. The growth was measured by spectrophotometry and iodonitrotetrazolium chloride. Antibiotic resistance genes (tet(O) and gyrA) were characterized at the molecular level. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) ranged from 25 to 1600 μg/mL. Cinnamon oil, (E)-Cinnamaldehyde, clove oil, eugenol, and baicalein had the lowest MIC and MBC values (25–100 μg/mL). MT947450 and MT947451 were sensitive to erythromycin and gentamicin but resistant to quinolones and tetracycline. Mutations in gyrA and tet(O) genes from resistant strains were confirmed by sequencing. The findings show that NPs are effective against drug-sensitive and drug-resistant Campylobacter strains. The resistance to antibiotics was confirmed at phenotypic and genotypic levels. This merits further studies to decipher the action mechanisms and synergistic activities of NPs
Thumbnail Image
Item
Decomposition of crotalaria and leucaena green manures and their nutrient release patterns
(Sokoine University of Agriculture, 1992) Nikokwe, Chais Adam
The decomposition of Crotalaria and ochroleuca Leucaena leucocephala green manures. contained in litter bags and placed on the surface (8- 10 cm), was The study was or buried 12 weeks of incubation. studied during conducted under laboratory conditions determine and compare decomposition and patterns of the two of green manure subsequent nutrient in soil microbial determined and the release was manure residual nutrient release Changes investigated numbers with and decomposition on application to green manures. The effect of method related into the soil to decomposition. materials, and were time incubation Analyses of counting microbial were done at three week intervals. The rate of decomposition was expressed dry matter. organic carbon phosphorus in parameters the in terms of total nitrogen and residual material organic. All these were expressed as percentages of the original quantities added through the manure. Generally six weeks decomposition was fast during the first of incubation and slowed down thereafter rate of decomposition was similar in and decomposed by almost 50 and weeks of incubation, respectively. The both green manures, 70% after in six and 12 addition they had incorporated manure soil releasing capacities. However similar nutrient more decomposed faster and released nutrients than surface-applied. In treated microbial numbers incubation after The soil there during rapid were the first which populations soil-incorporated green microbial numbers than increases in weeks of six almost levelled off. manure resulted in the surface-applied one. Larger In the control soil such changes were small. From the that when results of used the this study two green it was manures z incorporated into the soil at least six period when the intended nutrients. crop has This will allow speculated should be weeks before the its maximum need for synchronization of maximum nutrient release with high nutrient demand by the crop.
Thumbnail Image
Item
Effects of selected insecticides on microbial numbers,leucaena decomposition and biological nitrogen fixation
(Sokoine university of Agriculture, 1997) Ng'ang'a, Josephine Nyambura
The effects of Lannate and Karate on the decomposition of leucaena green manure and nitrogen fixation by cowpea were evaluated, after establishing their inhibitory effects on the decomposer microorganisms and their toxic effects on the bradyrhizobia in vitro.In the decomposition experiment,manure the in in the perforated plastic litter bags was buried (10 cm) soil contained in wooden troughs and the insecticides were applied on the soil at final concentrations of 0.5 and 1.5 ppm for lannate or and 0.51.0 ppm for decomposition process was monitored at 0, after weeks matter, and incubation by measuring residual organic carbon,inorganic-N heterotrophic content microbial of count karate.1, the 5 and 73,residual dry residual total nitrogen was the soil.The determined total at each sampling time.The effects of these insecticides each at 0.5 and 1.5 ppm on the covrpea-Bradyrhizobium symbiotic relationship were assessed in potted soil. Cowpeas were grown and harvested after 35 days. Nodule numbers and dry weight,shoot dry weight and nitrogen content were assessed.Results of these studies indicated that lannate and karate had an apparent depressive effect on the growth of the heterotrophs at the 0.5 ppm concentration but not at higher concentrations. The bradyrhizobial proliferation invitro was more affected by lannate than karate. However, nodulation and nitrogen fixation was not affected by any of the insecticides at significantly any of the the two concentrations tested.It was concluded from this study that insecticides, when applied even up to ten times the field recommended rate have no profound effects heterotrophic microorganisms, their ability to on the decompose leucaena green manure and on biological nitrogen fixationin cowpeas. However, the very severe depressive effect of lannate on the cowpea-bradyrhizobia in vitro, may warrant further studies in soils.