三株坦桑尼亚野生灵芝菌株人工栽培子实体活性成分含量分析

以国内灵芝(Ganoderma)栽培菌株粤GL-YW( G.lucidum)和粤GL-YWZ(G.sinense)为对照,对3株采自坦桑尼亚的野生灵芝(Ganoderma)菌株的人工栽培子实体进行多糖和三萜含量测定.结果表明,3个野生菌株子实体中多糖和三萜含量均显著高于对照菌株,值得进一步开发和推广.     

Canine Leishmaniasis: Parasitological Follow-up of the Treated Subject

A cross-sectional study was carried out to determine the prevalence of gastrointestinal (GI) nematodes and flukes (Fasciola and amphistomes) infection in communally grazed traditional cattle, zero-grazed small-scale dairy cattle and intensively grazed large-scale dairy cattle through examination of helminth eggs in faeces. Results indicated that the type of management, especially the grazing habit, has a significant influence on the prevalence and intensity of GI nematodes and flukes. The prevalence of GI nematodes in traditional, large-scale dairy and small-scale dairy cattle was 67%, 44.4% and 37%, respectively, with the highest faecal egg counts in calves. The overall prevalence of Fasciola gigantica in traditional, large-scale dairy and small-scale dairy cattle was 63.8%, 46.2% and 28.4%, respectively. The prevalence of amphistomes was 81.9%, 55.5% and 41.1% in traditional, large-scale dairy and small-scale dairy cattle, respectively. The high prevalence of flukes in the traditional system was attributed to communal grazing and watering management practices. Stomach flukes recovered in examined cattle at the abattoir were Calicophoron microbothrium and Cotylophoron jacksoni. About 42.1% of infected animals had both Fasciola and amphistomes. The prevalence of both GI nematodes and flukes varied greatly among villages and farms. The prevalence of both Fasciola and amphistomes was higher in adults (58.5%, 75.2%) than in yearlings (36.5%, 51.5%) or calves (24.9%, 47.2%). The variation in the prevalence of both GI nematodes and flukes among management and age groups within systems can be used as an entry point towards rational use of anthelmintics for each management system. More studies on seasonal transmission pattern of all these parasites are required in order to design rational, economic and locally sustainable parasite control programmes.     

Impact of Eucalyptus gall wasp,Leptocybe invasa infestation on growth and biomass production of Eucalyptus grandis and E. saligna seedlings in Tanzania

A study was carried out to determine the impact of Leptocybe invasa infestation on growth and biomass production of Eucalyptus grandis W. Hill ex Maiden and E. saligna Smith seedlings in Tanzania. Three- month old seedlings were infested with L. invasa. Twenty two weeks post infestation, heights of infested E. grandis seedlings were reduced by 39.6%, while diameters were reduced by 11.3% compared to uninfested seedlings. On the other hand, the heights of infested E. saligna seedlings were reduced by 38.2% and diameters were reduced 7.7% compared to uninfested seedlings. Dry weight biomass reduction of infested seedlings was significantly higher on stem and leaves than roots and branches of both E. grandis and E. saligna. The impact of L. invasa infestation on growth and biomass production was higher in E. grandis than E. saligna. Prevention and control of L. invasa infestation should be given priority. Similar future trials should examine other commercially grown Eucalyptus species in Tanzania.     

Effects of Treatment of Banana Corms with a Systemic Nematicide

Abstract

Unpared banana corms were dipped in 300 ppm Nemacur P^* for 10 min, 600 ppm for 5 min, and 1200 ppm for 5 s. Pared corms were dipped in 600 ppm for 5 min. Plants from pared corms were slower in growth and gave lower yields than plants from unpared corms. Retardation of growth was observed in plants from corms dipped in 300 ppm for 10 min, and from treated, pared corms, suggesting phytotoxic effects of Nemacur P at these rates of application. No phytotoxic effects were noted in the 600 ppm dip of unpared corms, or with the 1200 ppm dip. The 1200 ppm dip, and 600 ppm dip of pared corms were not effective in controlling nematodes. Best nematode control was obtained from dipping unpared corms in 600 ppm Nemacur P.     

Herbicide Performance in Rainfed Cabbage

Abstract

The effectiveness of butralin (2.0 and 4.0 kg a.i./ha pre-plant, 2.0 and 4.0 kg a.i./ha pre-em), chlorthal-dimethyl (10.0 and 12.0 kg a.i./ha pre-em), trifluralin (0.6 and 1.1 kg a.i./ha pre-plant) chloramben (2.0 kg a.i./ha pre-em) and nitrofen (2.0 kg a.i./ha pre-em) in controlling weeds in transplanted ‘Kono Cross’ cabbage and the influence of these treatments on the yield and quality of marketable heads and on the economics of weed control were evaluated in three replicated field experiments on River Estate loam soil in Trinidad during the wet seasons of 1976 and 1977. While herbicides did not affect the size of the cabbage plant population or the date to maturity of the crops, they reduced the cost of weed control by over 30% and increased the net returns relative to the clean-weeded control by over 9%. Butralin at 4.0 kg a.i./ha pre-plant and pre-em and the trifluralin treatments were superior to nitrofen which gave good weed control up to five weeks and higher yields than the clean-weeded control. Chlorthal-dimethyl gave encouraging results but caused slight, temporary stunting. The application of one of these treatments followed by one hand weeding at about four weeks should give full-season weed control and an acceptable yield of marketable heads with increased financial returns. Chloramben was the least effective herbicide tested and its use may not be justified under similar conditions to those of this study.     

Cultivation‐Induced Effects on the Soil Organomineral Matrix and Their Bearing on Crust Development on Two Soil Formations from Tanzania

Abstract

Land degradation as a result of land‐use practices is a major environmental concern to sustainable agricultural production in Tanzania. The effect of clearing and long‐term cultivation on physical, chemical, and biological characteristics is described in two representative soil formations from eastern Tanzania: Mkindo (Eutric Fluvisol) in the Mvomero district and Mafiga (Ferric Lixisol) in the Morogoro district. The results have shown that in the Mkindo site, 10 years of continuous rice cultivation has led to severe changes in most characteristics of the soil. Significant effects of cultivation coincide with those considered to favor clay dispersion and crusting phenomena, including changes in soil reaction, clay content, and mineralogy as well as generalized desaturation of the exchange complex, increasing sodicity, and severe losses of soil organic matter (SOM). In contrast, at the Mafiga site, 30 years of a less disturbing cultivation system, including periodic fallows, have also modified some soil characteristics but to a lower extent than at Mkindo. Decreased soil colloidal properties at the Mkindo site and lower stability against biological degradation, reflected by carbon (C)–release curves, than the Mafiga site could be causally connected to clay illuviation processes leading to accumulation of calcium (Ca) and magnesium (Mg) but mainly caused by changes in SOM characteristics such as losses of humic (HA) and fulvic acid (FA) and accumulation of humin.     

Accessory Minerals and Potentially Toxic Elements in Tanzanian Vermiculites with Respect to Agricultural Applications

The study assessed accessory minerals and metals in Tanzanian vermiculites with respect to their potential suitability for agricultural applications. Mineral and chemical analyses were involved. Pot experiments were also conducted to assess plant uptake of metals from soil with vermiculites. Fibrous sepiolite and amphiboles were minerals of health concern found in some samples. The sepiolite fibers had aspect ratios similar to those of asbestos minerals, which cause respiratory disorders and lung cancer when inhaled and thus pose a potential health risk to animals and humans. The amphibole fibers were thicker than 10 μm and are unlikely to be inhaled. Chromium (Cr) and nickel (Ni) concentrations in some samples were greater than the limits permitted in agricultural soils, but the elements are not highly plant available and do not inhibit the uptake of essential macronutrients. Heating vermiculites at 400–600 °C enhanced extractability of Cr and Ni and should preferably be avoided.     

中国援坦桑尼亚农业技术示范中心玉米试验结果初报

2011年,从中国引入自育为主的10个杂交玉米品种,在援建坦桑尼亚农业技术示范中心与3个当地常规玉米品种进行小规模品比与栽培技术试验。初步结果:旱季试验实测平均667m2产量,杂交食用糯玉米(鲜粒)为568～847kg,杂交饲料玉米(干粒)为381～517kg,而当地常规食用白玉米(干粒)仅296～357kg,说明中国杂交玉米品种在坦桑尼亚有显著的增产潜力。     

Spatial and temporal abundance of the solanum fruit fly, Bactrocera latifrons (Hendel), in Morogoro,Tanzania

Bactrocera latifrons is a newly invasive pest species in eastern Africa. Surveys to determine the spatial and temporal abundance of this fruit fly in the Morogoro Region, Eastern Central Tanzania, were conducted from April 2007 to March 2008. The surveys involved trapping of adult flies and collection of host fruits to determine the emergence of adults. The results indicated that the population of B. latifrons was generally low but that adult flies were present throughout the survey period. The population of B. latifrons based on infestation rates and incidence in host fruits, seems to be relatively high during the wet seasons, probably because of availability of many hosts. However, the population of the pest as determined by trapping, indicated a low population but without a specific pattern. The pest shows minimal response to the used attractants. The surveys further indicate that B. latifrons is more abundant in low to medium altitude areas compared to high altitude areas. The results indicate that, because of its low population, B. latifrons might be a minor pest. Results further suggest the possibility of establishing B. latifrons free areas where export valued solanaceous crops can be grown, but further research over longer periods would be needed to establish this.     

Seroprevalence Estimation and Risk Factors for <Emphasis Type="Italic">A. marginale</Emphasis> on Smallholder Dairy Farms in Tanzania

A cross-sectional serological survey of A. marginale was conducted on 200 randomly selected smallholder farms in each of the Tanga and Iringa Regions of Tanzania between January and April 1999. Sera, from dairy cattle of all ages, sexes and breeds were tested for antibodies against A. marginale using an indirect enzyme-linked immunosorbent assay. Antibodies to A. marginale were present in cattle throughout the study areas and the overall prevalence was 20% for Tanga and 37% for Iringa. The forces of infection based on the age seroprevalence profile were estimated at 8 for Tanga and 15 for Iringa per 100 cattle years-risk, respectively. In both regions, seroprevalence increased with age (β = 0.01 and 0.017 per year of age, p < 0.005, in Tanga and Iringa, respectively). Older animals in Iringa were significantly and negatively associated with decreased seropositivity (β = −0.002, p = 0.0029). Further results of logistic regression models reveal that geographic location of animals in Tanga was associated with seropositivity (odds ratio (OR) = 2.94, p = 0.005, for Tanga Rural and OR = 2.38, p = 0.066, for Muheza). Animals acquired as a gift in Iringa had higher odds for seropositivity than brought-in cattle (OR = 2.44, p = 0.005). Our study has identified and quantified some key risk factors that can guide planners devising disease control strategies.