Domestication of jute mallow (<Emphasis Type="Italic">Corchorus olitorius</Emphasis> L.): ethnobotany,production constraints and phenomics of local cultivars in Ghana

Jute mallow rich in proteins, vitamins and essential amino acids is an important leafy vegetable in Africa. Ethno-botanical knowledge on the crop in Ghana has been only incompletely documented and little is known about variation and diversity of local accessions. In order to document available ethnobotanical knowledge and investigate diversity of local accessions, 4000 farmers in twenty districts were surveyed using participatory rapid appraisal tools and techniques. 50 accessions of local germplasm were collected from these districts. Using randomized complete block design with three replications, the 50 accessions collected were characterized based on 12 quantitative and 6 qualitative traits. Results of the survey recorded several vernacular names of the crop and their meaning referring to the slimy nature of the leaves. Some local cultivars which were known in the past are no longer cultivated in farmers’ field suggesting genetic erosion of jute mallow in Ghana. Apart from food, respondents use jute mallow to treat fever, waist pain, stomach problems and loss of appetite indicating nutraceutical potential of the crop. Hierarchical cluster analysis grouped the accessions into four distinct clusters and individuals from the same geographical origin were separately classified. Quantitative traits such as leaf length, number of branches per plant, and number of leaves/plant defined the first principal component. Accessions Cagric 26, Cagric 28, Cagric 41, Cagric 08 and Cagric 01 recorded high yields. These accessions could serve as parents for breeding of improved cultivars.     

Growth,feed utilization,and liver histology of juvenile Nile tilapia (Oreochromis niloticus) fed diets containing increasing levels of swine fat

Due to predictions that the expanding aquaculture sector cannot continue to rely on finite marine stocks for fish oil, there have been several research works within the aquafeed industry to find sustainable alternatives for dietary lipid sources. This study was conducted to evaluate the effects of a range of inclusion levels of rendered swine fat on the growth performance and liver histology of juvenile Nile tilapia, Oreochromis niloticus. Fish (initial weight ~ 20 g) were randomly stocked into twelve 1 m³ nylon mesh hapas and fed isoenergetic and isonitrogenous diets containing rendered swine fat at varying inclusion levels of 0% (Control), 5% (SF5), 7% (SF7), or 10% (SF10) for 84 days. The control diet contained 5% fish oil as the lipid source. At the end of the trial, there were no significant differences between the final weights of the fish that were fed the control (38.01 ± 0.76) and SF5 diets (37.85 ± 0.68), and both groups recorded significantly higher (P < 0.05) specific growth rates relative to the SF7 and SF10 groups. Specific growth rates ranged from 0.59% day^?1 (SF10) to 0.75% day^?1 (Control and SF5). The fish that were fed the SF7 and SF10 diets had significantly (P < 0.05) larger livers relative to the control and SF5 fish. Histological examination further revealed significant liver alterations in the SF7 and SF10 fish, as evidenced by hepatocyte nuclei migration, hepatic vacuolation, and varying degrees of steatosis. Calculations of profit indices showed that the SF5 diet offers the best economic viability, taking into consideration both the monetary values of fish produced and cost of feed fed over the trial period. The results of this study indicate that rendered swine as a sole lipid source in juvenile Nile tilapia diets can be included at 5% without depressing fish growth.     

The effect of intermittent treatment with sulphadimidine on coccidiosis in preruminant calves

Preruminant calves excreted coccidia oocysts in their faeces after 3 weeks of group housing. Two weeks of oral sulphadimidine (SDM) administration, 50 mg/kg on the first day of treatment followed by daily administration of 37.5 mg/kg, under the same housing conditions kept the faeces free of oocysts. Three weeks later, these calves excreted oocysts again. Repetition of the same treatment for 2 weeks controlled the infection again, but a second treatment for 5 days did not suffice. The repeated long treatment affected immunoglobulin levels adversely. SDM given repeatedly at a lower dose rate (30 mg/kg) for 1-week periods with medication-free intervals of 1 week controlled the infection and no adverse effects were noted. In comparison with controls, weight gains were greater in treated calves.     

On the Use of the Perineal Stain as an Index of Sexual Maturity and Breeding Condition in the Male Greater Cane Rat,Thryonomys swinderianus,Temminck

The efficacy of the perineal stain as an index for sexual maturity and breeding condition in the male greater cane rat, Thryonomys swinderianus, Temminck, was investigated in 34 animals collected from hunters' kills in the Ekumfi District of Ghana, between April and June 1989. The results indicated that, although the presence of the perineal stain was conclusive proof of sexual maturity in an individual, it was not efficacious as an index for sexual maturity for biological work in these animals (p>0.05), because it excluded some that, although sexual mature, did not exhibit the trait, particularly young adults. However, the perineal stain may be useful as a management tool for identifying sexually mature captive greater cane rats. About 7 out of every 10 caught each month were found to be in breeding condition.     

Problems of potato cyst nematode pathotypes in the Czech Republic

During 1983–1989 about 1,200 infested plots in the Czech republic were investigated for the occurrence of new pathotypes of the potato cyst nematodes (PCN) Globoderu rostochiensis and G. pallida. Only eight populations of the pest were suspected of containing another pathotype than Ro1. Glasshouse pot trials were performed with those eight natural populations, two populations of Ro1, 10 potato cultivars resistant to Ro1 and 10 cultivars resistant to more pathotypes, G. pallida included. The multiplication rates (Pf/Pi) showed that four of the PCN populations were probably mixtures, with pathotype Ro1 prevailing. Three populations were suspected of containing G. pallida , but their morphological characters corresponded only with G. rostochiensis. One population corresponded with pathotype Ro5. The extent of the occurrence of pathotypes or virulence groups different from Ro1 can be estimated at 0.3–0.4% of infested plots.     

Serum-virus simultaneous method of immunisation against peste des petits ruminants

Summary Peste des petits ruminants (PPR) hyperimmune serum was prepared in cattle and used to protect goats against PPR. The serum was well tolerated by goats and 8 ml of serum was found to protect goats againts 4 ml of pooled virulent PPR virus. A durable active immunity was conferred on goats when serum and virulent PPR virus were given simultaneously. Passive immunity lasted for 15 days.

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Metodo Simultaneo Suero-Virus Para La Inmunizacion Contra La Peste De Pequenos Rumiantes

Resumen Se preparó en bovinos, suero hiperinmune de peste de pegueños rumiantes, para inmunizar cabras contra la enfermedad. El suero fué bien tolerado por las cabras, aplicandose hasta 8 ml para protegerlas de 4ml de virus virulento inoculado. El resultado de la aplicación simultánea de suero hiperinmune y virus virulento, fué el de una inmunidad activa y duradera. La inmunidad pasiva tuvo una duración de 15 días.

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Immunisation Contre La Peste Des Petits Ruminants Par Inoculation Simultanee De Virus Et De Serum

Résumé Le sérum hyperimmun de la peste des petits ruminants a été préparé sur des bovins et utilisé pour protéger les chèvres contre la PPR. Le sérum a été bien toléré par les chèvres et 8 ml de sérum ont été nécessaires pour protéger des chèvres inoculées avec 4 ml d'un mélange de virus PPR pathogènes. Les chèvres ont acquis une immunité active durable quand le sérum et le virus PPR pathologène étaient administrés simultanément. La durée de l'immunité passive a été de 15 jours.

     

Effect of soybean meal diets on the growth performance,ammonia excretion rates,gut histology and feed cost of Nile tilapia (Oreochromis niloticus) fry

Aquaculture development in Ghana is currently limited by inadequate supply of fingerlings and prohibitive cost of commercial feeds among other challenges. This study tested the feasibility of using low‐cost feeds containing soybean meal instead of fishmeal for nursing Nile tilapia (Oreochromis niloticus) fry. Three isonitrogenous (~48% crude protein) and isoenergetic (~17 kJ/g) diets with increasing inclusions of soybean meal as partial replacements for fishmeal were formulated. A commercial fishmeal‐based fry feed served as the control diet. Triplicate groups of 225 fish per tank (average initial weight: 2.09 ± 0.14 g) were stocked in a recirculating aquaculture system and fed the experimental diets for 21 days. Afterwards, we investigated the postprandial metabolism, nutrient digestibility, growth and gut histology in Nile tilapia fry. Simple economic analyses were also conducted to assess the cost‐effectiveness of the diets used in the feed trial. The dietary inclusions of the soybean meal significantly reduced feed cost by ~43% relative to the control diet. The growth performance and feed utilization parameters did not vary significantly among the different treatments. The soybean diets elicited significant reductions in villi heights and goblet cell numbers, which corresponded with increasing dietary levels of soybean meal. This study confirms the potential of soybean meal as a partial replacement for fishmeal in Nile tilapia fry diets in terms of lower feed costs, fish growth performance, nutrient digestibility and postprandial nitrogenous excretions. The inclusion of soybean, however, affected negatively the gut integrity of the fry.     

Inheritance of foliar resistance to <Emphasis Type="Italic">Phytophthora</Emphasis> species in cacao (<Emphasis Type="Italic">Theobroma cacao</Emphasis> L.): can it be influenced by CSSV infection?

Studies on quantitative genetics of foliar resistance to black pod disease in cacao could inadvertently use cocoa swollen shoot virus (CSSV) infected leaves which could bias the results especially in West Africa where the virus is prevalent. However, effects of CSSV on inheritance and heritability of foliar resistance to Phytophthora species is not known. Choice of an efficient breeding method requires an accurate estimation of genetic effects in selection schemes for foliar resistance to Phytophthora species in cacao. The objective of this study was to investigate the effect of CSSV infection on quantitative genetic parameters of foliar resistance to cocoa black pod disease in a population of 36 F1 hybrids developed by mating six cacao genotypes using a diallel method. The generated F1s and their parents were evaluated for foliar resistance to P. palmivora and P. megakarya using a randomized complete block design (RCBD) with three replications. 1A CSSV and Nsaba CSSV strains were used to infect the cacao genotypes using the patch graft method. The parents chosen showed significant variations for scores of leaf discs after inoculation with P. palmivora and P. megakarya. The leaf disc scores of CSSV infected crosses were lower than leaf disc scores of CSSV-free crosses. Genetic component analysis showed that the effects of GCA and SCA was significant for both CSSV-free and CSSV-infected crosses in resistance to P. palmivora and P. megakarya. The significant GCA and SCA for both CSSV-free and CSSV-infected crosses strongly suggest that both additive and non-additive genetic effects play an important role in the determination of inheritance of foliar resistance to Phytophthora species in cacao. There was significant variability in mean squares of GCA and SCA of CSSV-free and CSSV-infected crosses indicating that CSSV infection modifies GCA and SCA of affected plants. Narrow sense heritability was relatively low (0.31) for foliar resistance to P. palmivora and P. megakarya under CSSV-free and 1A CSSV strain infected conditions. However, heritability for foliar resistance to P. palmivora (0.43) and P. megakarya (0.36) was significantly higher under Nsaba CSSV infected condition. The modifications of mean squares of GCA and SCA and narrow sense heritability due to CSSV infection could mislead in choice of breeding methods indicating that attention must be paid to the infection status of plants when conducting quantitative genetics studies using diseased and healthy plants. CSSV status of leaf samples should be known before using them in leaf disc test. Genotypes Pa7/808 and Pound 7 had high negative GCA effects and are promising parents for enhancement of resistance to black pod disease in cacao.     

Common ragweed (Ambrosia artemisiifolia) dry matter allocation and partitioning under different nitrogen and density levels

Dry matter partitioning and allocation is a major determinant of plant growth and its competitiveness. Common ragweed (Ambrosia artemisiifolia) is a troublesome agronomic weed species and it is also a major health concern in Europe and many other countries because of its rapid spreading and production of allergenic pollen. A field experiment was conducted in 2009 to determine the effect of nitrogen fertilizer levels (0, 100, and 200 kg ha^?1) and plant density levels (1.3, 6.6, and 13.2 plants per m²) on the leaf, stem dry matter partitioning, and dry matter allocation of ragweed. With an increasing density, the stem partitioning coefficient increased, whereas the leaf partitioning coefficient decreased. The addition of nitrogen had a limited effect on the leaf and stem dry matter partitioning. The root dry matter production decreased with an increasing density and was not influenced by the addition of nitrogen. Under intraspecific competition, ragweed exhibited a stronger above‐ground competition intensity than below the ground, which resulted in a greater root : shoot ratio, compared to the low‐density stands. The level of nitrogen influenced the vertical leaf, stem, and total dry matter distribution, with a greater allocation to the top stratum of the plants, thus increasing their competition for light. The biomass allocation of ragweed to the roots in response to the nitrogen supply exhibited a low plasticity, compared to the shoots, which displayed a high plasticity. The results of this study suggested that, under intraspecific conditions and with an increasing nitrogen supply, ragweed would be more competitive in above‐ground resource acquisition.