Agroforestry training and extension: the experience from Haiti

An agroforestry project was funded by the US Agency for International Development and implemented by the Pan American Development Foundation in Haiti from 1981 to 1991. This project is considered by many to be one of the most successful projects of its kind in Haiti, and in the tropics as a whole. Over the ten years of its implementation, the project, referred to in Haitian Creole as Pwoje Pyebwa (Tree Project), evolved from a tree production and planting project to a much broader soil-conservation-based program involving trees. This paper summarizes the training and extension systems that developed during that period. The socioeconomic background studies that were done before the project began, and the flexible, consultative mode of field-team implementation, incorporating elements of the learning process approach, were important to the success of the project. During the implementation of the project, however, concern for farmer input and participation should have been incorporated more systematically into the field operations of the regional teams.     

Fouling and predation; how do they affect growth and survival of the blacklip pearl oyster, Pinctada margaritifera, during nursery culture?

This paper reports on 5 experiments conducted to assess the effect of cleaning regime and predation on growth and survival of blacklip pearl oyster (Pinctada margaritifera) juveniles in north Queensland, Australia. P. margaritifera juveniles with a mean (±SE) dorso-ventral shell height (DVH) of 4.5 ± 0.1 mm were placed into plastic mesh trays and cleaned either every 4 or 8 weeks or left uncleaned for 16 weeks. Cleaning regime had a significant effect on growth and survival (P < 0.005). Lowest DVH (16.2 ± 1.0) was shown by oysters in uncleaned trays during 16 weeks compared to oysters in cleaned trays; however, there was no significant difference in DVH between oysters held in trays cleaned every 4 (19.4 ± 1.2) or 8 weeks (21.2 ± 0.8). In contrast lowest survival was shown by oysters held in trays that were cleaned every 4 weeks (30 ± 5%), but no differences were noted between oysters cleaned every 8 weeks (63 ± 4%) and oysters that were left uncleaned for 16 weeks (75 ± 8%). Predators of P. margaritifera in northern Australia included crabs, stomatopods, flatworms, gastropods and fish. The stomatopod, Gonodactylus falcatus, was the most destructive predator with individuals consuming in excess of 20 juvenile pearl oysters per week. The leather jacket, Paramonocanthus japonicus, did not kill pearl oysters, but trimmed the margin of oysters shells significantly reducing DVH when compared to control groups cultured without fish. Removing predators monthly had a significant effect on growth of pearl oysters compared to oysters in non-inspected trays; however monthly inspection of culture trays did not significantly improve oyster survival. This revised version was published online in August 2006 with corrections to the Cover Date.     

Prevalence and Significance of Parasites of Horses in Some States of Northern Nigeria

This study was conducted to determine the prevalence and significance of parasites of horses in northern Nigeria. Blood and faecal samples were randomly collected from 243 horses from different stables in some states of northern Nigeria for laboratory analyses. Fifty-seven horses (23.5%) were found infected with parasites. The hemoparasites detected, 21 (8.6%), include Theileria equi, Babesia caballi, Trypanosoma vivax and Trypanosoma evansi. The endoparasites encountered, 29 (11.9%) were Strongylus spp., Strongyloides spp., Oxyuris equi, Parascaris equorum, Paragonimus spp. and Dicrocoelium spp., 3 (1.2%) was Eimeria spp. Four horses (1.6%) had mixed infection of hemo- and endoparasites. This preliminary finding shows that parasitism is a problem in the horse stables examined, and calls for proper stable hygiene, routine tick control and regular deworming programme.     

Differential evolution algorithm for solving multi-objective crop planning model

This study presents four strategies of a novel evolutionary algorithm, multi-objective differential evolution algorithm (MDEA). The four strategies namely, MDEA1, MDEA2, MDEA3 and MDEA4 are adapted to solve the multi-objective crop planning model with multiple constraints in a farmland in the Vaalharts irrigation scheme (VIS) in South Africa. The three objectives of the model are to minimize the total irrigation water (m²) and to maximize both the total net income in South African Rand (ZAR) from farming and the total agricultural output in tons. The total area of the farm is 771,000 m² and supplied with 704,694 m² of irrigation water annually. Numerical results produce non-dominated solutions which converge to Pareto optimal fronts. MDEA1 and MDEA2 strategies with binomial crossover method are better for solving the crop planning problem presented than MDEA3 and MDEA4 strategies with exponential crossover method. MDEA1 found a solution with the highest total net income of ZAR 1,304,600 with the corresponding total agricultural output, total irrigation water and total planting areas of 316.26 tons, 702,000 m³ and 725,000 m², respectively. The planting areas for the crops in the solution are 73,463 m² for maize, 551,660 m² for groundnut, 50,000 m² for Lucerne and 50,000 m² for Peacan nut. It can be concluded that MDEA is a good algorithm for solving crop planning problem especially in water deficient areas like South Africa.     

Farmlink: promoting conservation buffers farmer-to-farmer

Farmer-to-farmer outreach was used within a targeted watershed to promote the installation of conservation buffers. In this program called “FarmLink”, four farmers/landowners were employed part-time as “advisors” and trained by University of Nebraska-Lincoln Extension, Natural Resources Conservation Service, and Natural Resources District personnel. Topics included basic buffer design and benefits, availability of incentive programs, and sales techniques. These individuals then contacted their neighbors to explain the need for and benefits of buffers and other conservation practices. In early 2003, 42 landowners were contacted, leading to contracts for the establishment of 16 separate conservation practices on 24.8 ha (61.3 acres) of farmland. These included just over 8 ha (20 acres) of grassed waterways or similar plantings and 14 ha (35 acres) of streamside buffers. In addition, because of information received in the training sessions, one of the advisors installed 1.7 ha (4.3 acres) of streamside buffers, 0.45 ha (1.1 acres) of grassed waterways, and 2.0 ha (5.0 acres) of grasses and forbs on his own land. During these contacts, it became apparent that: (1) many farmers and landowners were not familiar with the multitude of programs available to assist with the installation and maintenance of conservation practices; and (2) landowners generally appreciated the personal touch of someone coming out to talk directly to them, pointing out specific areas on their land where conservation practices could best be implemented, discussing available compensation programs, and describing management needed to help ensure practice success. Although one-to-one contacts cannot be used in all cases, it was demonstrated to be effective in this watershed.     

Geographical information system (GIS) mapping of spatio-temporal pollution status of rivers in Ibadan, Nigeria

More accurate spatio-temporal predictions of urban environment are needed as a basis for assessing exposures as a part of environmental studies and to inform urban protection policy and management. In this study, an information system was developed to manage the physico-chemical pollution information of Ibadan river system, Oyo State, Southwest Nigeria. The study took into account the seasonal influences of point and non-point discharges on the levels of physico-chemical parameters. The overall sensitivity of the watershed to physicochemical environmental pollution revealed that during dry season, of the 22 (100%) sample points, only 3 (13.6%) were unpolluted; 6 (27.3%) were slightly polluted; 10(45.4%) were moderately polluted; 2 (9.1%) were seriously polluted and 1 (4.5%) was exceptionally polluted. During rainy season, 3 (13.6%) were unpolluted; 7 (31.8%) were slightly polluted; 9 (40.9%) were moderately polluted; 2 (9.1%) were seriously polluted and 1 (4.5%) was exceptionally polluted. There is a considerable environmental risk associated with the present level of pollution of the Ibadan river water body on fish health and biodiversity. This research provides a basis for aquatic management and assist in policy making at national and international levels. Appropriate strategies for the control of point and non-point pollution sources, amendments and enforcement of legislation should be developed.     

Trypanosomosis and reproduction: I. effect ofTrypanosoma vivax infection on the oestrous cycle and fertility in the ewe

Summary Ten West African Dwarf ewes were inoculated withTrypanosoma vivax and, at varying intervals, treated subcuratively with diminazene aceturate to maintain the infection. Soon after infection all ewes and anoestrus for 40 to 96 days and 5 died by day 110 post infection. Compared to control animals, infected ewes had prolonged low levels of plasma progesterone until recovery or death. However, no gross or histological lesions were detected in the endocrine or reproductive organs. Of the survivors, the 5 that were aparasitaemic subsequently became pregnant and had normal gestations.

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Tripanosomiasis Y Reproduccion: I. Effecto E Infecciones ConTrypanosoma vivax Sobre El Ciclo Estrual Y Reproduccion En La Oveja

Resumen Se inocularon 10ovejas West African Dwarf conTrypanosoma vivax y fueron tratadas periódicamente con dosis subcurativas de aceturato de diminazene, para mantener la infección. Pronto despues de la infección, todas las ovejas presentaron anestro por 40 a 96 dias y 5 murieron 110 dias después de la infección. Comparadas con controles, las ovejas infectadas presentaron niveles bajos de progesterona plasmática, hasta recuperación o muerte. Sin embargo, no se encontraron lesiones macroscópicas ni histológicas en los órganos reproductivos o endocrinos. De las sobrevivientes, las 5 que fueron aparasitémicas quedaron posteriormente preñadas y tuvieron gestaciones normales.

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Trypanosome Et Reproduction. I. Effet De La Trypanosomose AT. Vivax Sur Le Cycle Oestral Et La Fecondite Chez La Brebis

Résumé Dix brebis naines de l'Afrique de l'ouest ont été inoculées avecTrypanosoma vivax et, à intervalles variés, traitées avec e l'acéturate de diminazène à dose non curative pour maintenir l'infection. Peu après celle-ci, toutes les brebis ont présenté un anoestrus de 40 à 96 jours et 5 sont mortes le 110e jour après l'infection. Comparées aux animaux témoins, les brebis infectées ont montré des taux peu élevés et polonges de progestérone du plasma jusqu'à leur guérison ou leur mot. Cependant, aucune lésion importante ou histologique n'a été décelée dans les organes de reproduction ou endocriniens. Parmi les survivantes, les 5 qui n'étaient pas parasitées sont entrées en gestation et l'ont menée normalement à terme.