Uganda Journal of Agricultural Science (UJAS)
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Productivity and profitability of robusta coffee agroforestry systems in central Uganda
Get PDFTo contribute to understanding the socio-economic impact of shade trees and the returns fromrobusta coffee farming systems, this study compared the financial profitability of shaded coffee fields which are dependent on nutrient cycling to sustain production (traditional system) and shaded coffee fields where compost manure are applied, under small-scale farmer conditions. It also analysed the contribution of shade trees to the overall profitability of robusta coffee farming in central Uganda. The study revealed that shaded coffee yielded substantial returns from shade tree products,amounting to 53.3 and 42.5 % of the gross annual income in traditional and compost coffee options respectively. Although the mean coffee productivity per acre from coffee fields with compost manure (748 kg acre-1 yr-1) and traditional low input (486 kg acre-1 yr-1) were significantly different (p-value < 0.05), the difference in net present values was small due to the higher annual maintenance costs in the compost option. The discounted cash flow at 10% real discount rate indicated that the net present values of the traditional and compost options were (US5607 acre-1) respectively, considering exclusive use of family labour. Profitability of the coffee agroforestry system can be significantly improved by increasing coffee stocking density from the current average (340 coffee trees acre-1) to the recommended stocking density of 450 coffee trees acre-1 and by farmers providing own manure instead of buying
Reduction of the ngege, Oreochromis esculentus (Teleostei: Cichlidae) populations, and resultant population genetic status in the Lake Victoria Region
Get PDFNgege, Oreochromis esculentus, originally formed the mainstay of the Lake Victoria Region (LVR) fisheries. Together with its indigenous congener O. variabilis, it was displaced from Lakes Victoria and Kyoga of LVR and was found to survive as isolated small populations within the peripheral minor lakes and reservoirs around the two lakes. Displacement of the two LVR indigenous tilapiines was thought to be principally driven by changed lake environment and predation by the introduced Nile perch, but also competition and genetic swamping by the closely related introduced and comparatively more ecologically versatile tilapine species. In a study carried out in the LVR between 1993 and 2003, micro satellites and RAPD markers were used to analyse the remnant populations so as to establish the population structure and extant genetic diversity of O. esculentus. Analyses indicated that the survivingˆ O. esculentus retained a high proportion of genetic diversity with high differentiation between units an indication of genetic exchange between indigenous and introduced Nile tilapia where the two forms co-existed. While this heightened concern for genetic swamping of the remnant population units by the introduced tilapiines it was noteworthy that in a few of the satellite lakes where the O. esculentus was dominant evidence for introgression was weak
Molecular diagnostic tools targeting different taxonomic levels of Xanthomonads aid in disease management
Get PDFEffective plant disease management requires quick, accurate and specific diagnostic techniques, which in turn help in disease surveillance, regulation of material movement and ensure good quality planting material. When investigating emerging diseases with no existing specific diagnostic protocols, it can be useful to apply tools detecting all members of a genus as one. On the other hand, the banana xanthomonas wilt devastating East and Central Africa had no specific detection tool available over ten years after its first report. In this article, we present molecular diagnostic tools developed for genus, species and pathovar specific detection of Xanthomonas campestris pv. musacearum (Xcm). The tools included; i) primers developed based on the internal transcribed spacer region (ITS) of the ribosomal DNA (X-ITS) and a xanthan biosynthetic gene (gumD) (X-gumD) for genus level Xanthomonas detection; ii) primers based on the hypothetical protein NZ_ACHT01000085 (NZ085) for specific detection of the species X. vasicola and the general secretion protein D NZ_ACHT01000280 (GspDm) for specific detection of Xcm. The X- ITS and X-gumD primers specifically amplified DNA from xanthomonads giving 254 and 402 bp fragments, respectively without amplifying DNA of non-xanthomonads. PCR primers NZ085 specifically amplified a 349 bp fragment from DNA of Xcm, X. vasicola pv. holcicola (Xvh) and X. axonopodis pv. vasculorum (Xav) proposed to belong to the species X. vasicola. The GspDm primers amplified a 265bp DNA fragment of Xcm isolates tested with no DNA amplification of other plant associated-bacteria, including the two closely related Xvh and Xav. This provides a promising disease detection approach for both unknown and suspected pathogens
Effect of method of storing cattle faeces on the physical and chemical characteristics of the resultant composted cattle manure
Get PDFThe growing population of dairy cows in urban and peri-urban areas coupled with improvement in feeding is generating more manure, which if properly conserved can become an input to crop/ fodder production. The objective of this study was to investigate whether the method of storing faeces excreted by cows fed on Pennisetum purpureum–legume foliage diets affects the manuring quality of the resultant manure. Four diets comprising sole Pennisetum fodder, Pennisetum + Calliandra, Pennisetum + Centrosema and Pennisetum + Desmodium were fed to cows. Faeces excreted were subjected to four methods of storage for three months as follows: Placing faeces in pits and covering with soil (T1), wrapping faeces in polythene sheets and placing them in pits (T2), placing faeces in pits and leaving the pits open (T3), and stockpiling faeces on open flat ground (T4). Composts derived from faeces subjected to T3 and T4 methods exhibited maturity. Apart from nitrogen in the compost derived from faeces of cows supplemented with Calliandra, the nitrogen, phosphorus and potassium concentrations in all the composts significantly declined. Organic matter losses from composts got from T3 and T4 were significantly greater than that of T2. It was concluded that storing cow’s faeces using T3 method would be the most appropriate and low-cost management intervention for improving cattle manure nutrient conservation
Effect of legume foliage supplementary feeding to dairy cattle offered Pennisetum purpureum basal diet on feed intake and manure quality
Get PDFIn smallholder zero grazing dairy systems of Uganda, elephant grass (Pennisetum purpureum) is the main basal diet offered, and is supplemented with legume forages among others. Recent observations indicate reduction in fodder yields of P. purpureum although farmers are applying cattle manure to improve soil fertility and hence increase fodder production. This study evaluated the effect of legume supplementary feeding to dairy cattle offered P. purpureum basal diet on feed intake, and the output and manuring qualityof the resultant faeces. Four diets consisting of P. purpureum fodder fed ad libitum as a control, P. purpureum + Calliandra, P. purpureum + Centrosema and P. purpureum + Desmodium were offered to cows in a 4 x 4 switchover Latin square design. Legume supplementation increased (P<0.05) the total organic and dry matter, metabolisable energy (ME) and nutrient intake, and the apparent dry matter digestibilities (ADMD) as compared with the control. Faecal excretion was increased (P<0.05) by Calliandra and Centrosema. Cows which were supplemented with Calliandra excreted (P<0.05) larger amounts of N, P and K than cows fed either Centrosema or Desmodium. Supplementation with Calliandra proved to be better option since it enhanced feed intake and the output and quality of faeces that could be recycled within the crop-livestock production systems
Estimating the premium for titled agricultural land in Uganda
Get PDFThis study investigates the value for titled agricultural land in Uganda using data on 9,185 parcels of land from the 2005/2006 Uganda National Household Survey. Data were analysed using regression techniques. The results showed that land titles had a positive influence on agricultural land prices although the premium was significant for leasehold title as opposed to other forms of title; that except for current agricultural use, traditional determinants of land value such as soil quality, presence of perennials and proximity to the homestead are not significant for agricultural land in Uganda; and that per acre price of agricultural land in peri-urban locations was significantly higher than in rural areas by about 87%. The overlap in land ownership rights for mailo land where two people have claims to the same piece of land, the mailo title holder and the kibanja tenant, placing constraints on its transfer was not reflected in its perceived market price. It was concluded that the current land policy should promote the leasehold system in upcoming cities and peri-urban areas, since this type of tenure opens land to a wide range of users and use-options. The land policy also needs to address the double ownership structure under the mailo tenure which constrains its transferability to make the positive effects of having such titles more significant in the land market
Combining ability and heritability for host resistance to Aspergillus flavus and Aflatoxin accumulation in tropical mid-altitude maize
Get PDFAflatoxins are toxic, and highly carcinogenic secondary metabolites of Aspergillus flavus and Aspergillus parasiticus. They pose a serious health hazard to humans and animals that consume contaminated grain. Recently, the National Maize Breeding Program at National Crop Resources Research Institute (NaCRRI) incorporated breeding for resistance to A. flavus infection and aflatoxin accumulation in its initiative to improve maize grain quality in Uganda. The breeding strategy had three major components: (i) identifying locally adapted, elite germplasm with resistance to A. flavus and reduced aflatoxin accumulation, (ii) improving locally adapted, elite germplasm for host resistance, and (iii) formation of new populations for pedigree breeding. To identify sources of resistance, we first compared effectiveness of media plating and media free techniques for assessment of kernel infection rate (KIR) on various germplasm. We generated 144 three-way test crosses and screened them together with their parental inbred lines and 4 single cross testers for host resistance to A. flavus and reduced aflatoxin accumulation. Using line by tester analysis, we identified 5 resistant inbred lines and 7 hybrids. We used the resistant inbred lines to make crosses with new sources of resistance from International Center for Maize and Wheat Improvement (CIMMYT) and International Institute for Tropical Agriculture (IITA) in diallel design. To strengthen this work, we conducted a survey to assess farmers’ knowledge on A. flavus and aflatoxins and their management practices. Results obtained provided us with a foundation for development and deployment of new germplasm with resistance to A. flavus and aflatoxin accumulation for improved grain quality for both domestic consumption and export
Farmers’ knowledge, perceptions and control of pestiferous termites in Nakasongola district, Uganda
Get PDFThis study documented farmers’ indigenous knowledge on termite damage and management practices in Nakasongola district, Uganda using a pre-tested questionnaire. The majority (84%) of 94 farmers interviewed were aware of the termite damage on vegetation in rangelands and croplands, and the damaging termite species. Pseudacanthotermes militaris, Macrotermes subhyalinus, M. bellicosus, Nasutitermes arboreus and Eutermes arborum were reported to cause severe damage to pasture grass, trees and/or crops. Farmers’ knowledge of termite damage was significantly influenced by their age, sex and education. About half of the farmers had attempted to control termites, but with little success. Application of chemicals was the most commonly reported control method followed by queen removal. Farmers’ efforts to control termites were mainly limited by high costs of chemicals and lack of knowledge on effective control methods. Implications of these findings on the development and promotion of integrated termite management strategies are discussed
Comparative pre-weaning growth of Zebu cattle and their crosses with Sahiwaland Boran
Get PDFA study was carried out to evaluate growth performance of Zebu cattle and their crosses with Sahiwal and Boran at the National Semi-Arid Resources Research Institute (NASARRI), Serere, Uganda. Analysis of variance based on General Linear Model of SAS 2002 was used to analyse the data. The overall means for weights at birth and weaning and pre-weaning average daily gain (ADG) were 18.36± 0.076, 100.55 ± 0.48 kg and 304 1.96 g day-1, respectively. Dry season born calves were significantly (P<0.05) superior to wet season born in both weaning weight and pre- weaning ADG. Parity had a significant (P<0.05) influence on birth weight but not for weaning weight and pre-weaning ADG. Genetic group of the calf (Zebu, Boran or Sahiwal crosses) was a significant (P<0.001) source of variation for all growth traits studied. Rankings of genetic groups for weaning weight and pre-weaning ADG were B1Sx (SxT), F1(SxT), B1(SxT)xT, B1Bx(BxT), F1(BxT) and T. Influence of year calving was significant (P<0.01) for weaning weight and pre- weaning and pre-weaning ADG but not for birth weight. Heritability estimates based on sire variance components for birth weight, weaning weight and pre-weaning ADG were 0.41, 0.02 and 0 .02, respectively. Heritability estimates based on both the dam and the sire variance components for birth weight, weaning weight and pre-weaning ADG were 0.41, 0.16 and 0.36, respectively. Based on these results it can be suggested that crosses of Boran and Sahiwal have higher potential for growth than the Zebu cattle. However, backcrossing to either Sahiwal or Boran breeds had no significant advantage over the F1crosses
Male fertility in Musa: Pollen quality in diploid banana hybrids
Get PDFBanana production in the East African region is constrained by a variety of pests and diseases. Host plant resistance is the most convenient and effective intervention to circumvent these constraints in banana production. However, male fertility is a major limitation in the genetic improvement of bananas. Pollen quantity and quality are the key attributes in selecting male parents for successful banana crosses. Pollen was collected from 22 candidate diploid banana hybrids and 6 diploid genotypes previously, successfully used in breeding programs. It was examined for pollen quantity, staining with Iodine Potassium Iodide (I2KI, Lugol stain), and germination frequency on a nectar-water medium. The traits under examination varied significantly (P≤0.05) among diploid banana hybrids. I2KI-stained pollen frequency ranged between 12.96% for hybrid ‘12506S-1’ to 100% for ‘3162K-1’, while pollen tube germination frequency ranged from 1.67% on ‘2858K-5’ to 95.66% on ‘Calcutta 4’. Relative pollen quantity, I2KI-stained pollen frequency, and pollen germination frequency were significantly, positively (P≤0.05) correlated. Five diploid banana hybrids, i.e. ‘12506S-29’, ‘Opp2-861’, ‘3162K-3’, ‘3146K-3’, and ‘3146K-2’, were selected as male parents to be incorporated into the breeding programs.