Using a whole-farm modelling approach to assess prospective technologies under uncertainty

New technologies may be adopted by farmers if they fit farmers’ resource endowments, objectives and goals, and attitudes towards risk. In this paper, the role of whole-farm modelling in technology evaluation is discussed. An assessment of prospective technology options for wheat and sugar beet in a study region in Iran is presented. Data on new technologies were collected from farmers of Fars province, staff of the Shiraz Branch of the Agricultural Research Centre, the Regional Branch of the Extension Organization, and from the Shiraz University’s Research Centre. An extension of utility efficient programming to non-linear discrete stochastic programming, was adopted to evaluate prospective technology options. Results of the study demonstrated the merits of the technique, and it was found that farmers’ total net revenue would increase considerably if adoption was to occur.     

Artificial Insemination with Frozen Semen in Ewes at Different Times of the Breeding Season

Totally 13575 ewes of two different breeds, Dala and Spel, were inseminated with semen, frozen in straws and thawed at 70°C for 8 sec. An insemination dose of 0.2 ml containing approx. 150 × 10⁶ spermatozoa with at least 45 to 50% progressive motility was imerted 5 to 12 mm into the cervix. The insemination was performed once between 12 and 30 h after the onset of heat. The NR rate of the Dala ewes increased significantly during the season. The NR rate of the ewes inseminated before 15. November was 44.3%, from 15. to 20. November 52.2%. from 20. to 25. November 55.3% and from 25. November and later 61.4%. The corresponding values for the ewes of the Spel breed were 57.3, 58.7, 61.5 and 71.0% respectively, and only the difference between the two last values was statistically significant. The difference between the fertility of the two breeds was significant within each of the periods .     

An evaluation of the structure and function of tropical homegardens

Homegardens represent land use systems involving deliberate management of multipurpose trees and shrubs in intimate association with annual and perennial agricultural crops and, invariably, livestock, within the compounds of individual houses, the whole crop-tree-animal unit being intensively managed by family labour. Known by different names in various places, these agroforestry systems are common in all ecological regions of the tropics and subtropics, especially in humid lowlands with high population density.An analysis of the structural and functional aspects of ten selected homegarden systems from different ecological and geographical regions shows that the average size of the homegarden units is less than 0·5 ha; yet they are composed of a large number of woody and herbaceous species, carefully structured to form 3–5 vertical canopy strata, with each component having a specific place, as well as function.Food production is the primary function of most homegardens, the vast majority of them being subsistence production systems. While there is a remarkable similarity among the different homegardens with respect to the type and nature of the herbaceous crops, the nature of woody perennials varies, depending on environmental and ecological factors. In general, most woody components produce fruits or other types of food in addition to other outputs such as fuelwood, timber, etc. These various food products provide a substantial proportion of nutritive and energy requirements of the local diet. Moreover, the species diversity and varying production cycles of the different components ensure continuous production throughout the year from the homegarden unit.Little or no research has been done to improve homegarden systems. Structural complexity, species diversity, multiple output nature, tremendous variability from farm to farm, etc., are some of the main characteristics that make the homegardens extremely difficult models to work with according to the currently available research procedures.     

The threshold of successful attack by Ips typographus on Picea abies: A field experiment

The spruce bark beetle, Ips typographus, was induced to attack Norway spruce by means of pheromone dispensers. The degree of attack on each tree was recorded and the trees were later categorized as surviving or dying, according to the degree of sapwood blue-staining caused by the attacks. A threshold of successful attack was observed; i.e. above a certain number of attacks the trees were successfully invaded by the beetles and their mutualistic blue-stain fungi. The height of this threshold increased with increasing tree vigour, measured as the relative increment of the sapwood cross-sectional area.     

Micro-scale soil variability along a short moraine ridge at Okstindan,Northern Norway

Four soils developed along a moraine ridge crest are described. Morphologically three of the four soils had distinct podzol (Spodosol) profiles. When the chemical and morphological criteria used by three classification systems and the F.A.O. soil map legend are applied to the soils, however, this results in a divergence in the classification/designation of the four soils.Local differences in the height of the ridge crest above the adjacent till plain, are thought to be sufficient to cause changes in the micro-climate along the ridge. These differences in micro-climate appear in turn to influence the pattern and extent of colonisation by vegetation along the ridge crest. These two factors interact to produce the observed intensification of podzol development along the ridge crest from site 4, the most exposed site, to site 1, the least exposed site.     

Aquaculture Farm Food Safety and Diseases Risk Assessment (AquaFRAM): Development of a spreadsheet tool for salmon farms

Atlantic salmon (Salmo salar) is the most significant aquaculture species in Europe, both in terms of production and economic value, with Norway, followed by Scotland and Ireland as the three major European producers. The objective of the present study was to develop a spreadsheet tool for aquaculture farm-food safety and diseases risk assessment (AquaFRAM) for salmon farms in the UK, (and possibly more widely) to encourage farms to assess potential hazards and diseases. AquaFRAM functions primarily as a self-assessment risk ranking and risk-learning tool to determine the potential of farm food safety hazards, diseases and the level of possible risk for contamination and infections. AquaFRAM has been developed using MS Excel software utilising a qualitative risk assessment approach for farmers to evaluate their food safety practices and diseases on their farms. The risk assessment is based on the risk matrix of frequency of likelihood × severity, where the farmers can judge the likelihood of the hazards occurring on their farm based on given examples or scenarios. Grounding of the model, based on severity scoring is predicated on relevant reports in the literature and expert opinion derived from a separate Delphi study. The AquaFRAM Tool has since been tested on 9 salmon companies throughout UK. All of the farms which tried and tested the AquaFRAM Tool reported it being farmer-friendly and practical. It was highlighted that the current tool focused mainly on risk reduction and not risk elimination. However, such farm food safety and diseases risk assessment tool would be helpful, and certainly timely, to further encourage farms to assess potential hazards and diseases. It is also appropriate for educational and training of full-time and seasonal farm workers.     

Review of morphological and behavioural differences between reared and wild individuals: Implications for sea-ranching of Atlantic salmon, Salmo salar L., Atlantic cod, Gadus morhua L., and European lobster, Homarus gammarus L.

Abstract The main question which must be raised when planning to enhance natural populations through sea ranching is whether reared organisms are fit for a life in the wild, or more specifically, whether there are differences between reared and naturally resident individuals. The causes and effects of these differences are reviewed, and results from the Norwegian enhancement programme, which compared reared and wild individuals of Atlantic salmon, Salmo salar L., Atlantic cod, Gadus morhua L., and European lobster, Homarus gammarus L., are discussed with emphasis on morphological and behavioural differences. It was concluded that exposure to an artificial rearing environment during ontogeny can affect both the phenotype and the behaviour of the reared individuals, and thereby, their potential for survival after release into the wild as well. Suggestions are made as to how to diminish observed differences, and thereby, improve the survival potential.     

Mechanical injury and fungal infection induce acquired resistance in Norway spruce

Norway spruce trees (Picea abies (L.) Karst.) pretreated by wounding and fungal infection showed highly enhanced resistance to a subsequent challenge inoculation with the pathogenic bluestain fungus Ceratocystis polonica (Siem.) C. Moreau. This is the first time the effectiveness of the constitutive and inducible defenses has been shown to depend on prior wounding and infection in conifers, although such acquired resistance has previously been found in several angiosperms. Trees that were pretreated with a combination of 12 bark wounds (1.6 x 10 cm), four fungal inoculations and four sterile inoculations 1-15 days before mass inoculation with C. polonica at 400 inoculations per square meter over a 0.8 m stem section had significantly shorter necroses in the phloem, less bluestained sapwood, and less dead cambium than untreated control trees. Pretreatment with four fungal or sterile inoculations alone did not lead to enhanced resistance. Pretreatment by bark wounding alone seemed to provide an intermediate degree of resistance compared to bark wounding, fungal inoculations and sterile inoculations combined. All trees had a marked increase in the number of resin ducts in the year of inoculation compared with previous years, suggesting that formation of traumatic resin ducts play an important role in the development and maintainance of enhanced resistance.     

Chromosomes of salmon (Salmo salar) by leukocyte culture

Chromosome preparations from salmon (Salmo salar) were obtained by means of leukocyte culture. The chromosome number varied from 55 to 60 with a clear maximum of 2n = 58. The chromosomes are tentatively grouped as follows: group A, two large submetacentrics; group B, 14 metacentrics; group C, two large telocentrics; group D, 22 medium telocentrics; group E, 18 small telocentrics.