Limited ecoclinal variation found in Malva parviflora (small-flowered mallow) across the Mediterranean-climatic agricultural region of Western Australia

Malva parviflora L. populations were collected from 24 locations across the Mediterranean-climatic agricultural region of Western Australia and grown in Perth in a common garden experiment. Seventeen morphometric and taxonomic measurements were taken and genetic variation was investigated by performing principal components analysis (PCA). Taxonomic measurements confirmed that all plants used in the study were M. parviflora. Greater variation occurred within populations than between populations. Separation between populations was only evident between northern and southern populations along principal components 2 (PC2), which was due mainly to flowering time. Flowering time and consequently photoperiod were highly correlated with latitude and regression analysis revealed a close relationship (r(2) = 0.6). Additionally, the pollination system of M. parviflora was examined. Plants were able to self-pollinate without the need for external vectors and the pollen ovule ratio (31 +/- 1.3) revealed that M. parviflora is most likely to be an obligate inbreeder with a slight potential for outcrossing. The limited variation of M. parviflora enhances the likelihood of suitable control strategies being effective across a broad area.

Rethinking the development, dissemination and adoption of agricultural technologies

This paper focuses on the higher order factors affecting successful adoption of technologies. Drawing on the "actor-oriented perspective" in rural sociology, it is argued that successful examples of adoption at this higher level result from a complex conjunction of people and events, with outcomes that may have been quite unanticipated at the outset. From this perspective, research and extension projects and programs are viewed as arenas in which social actors–village leaders, farmers, researchers (local and international), aid officials, municipal agents, extension workers, and traders–pursue their own short- and long-term objectives and strategies. To this end, they maneuver, negotiate, organize, cooperate, participate, coerce, obstruct, form coalitions, adopt, adapt, and reject, all within a specific geographical and historical context.

Migration of Husbands, Remittances and Agricultural Production: Impacts when Wives Head Households in Rural Kenya

This paper uses data collected from migrants' wives in the Nyeri district of Kenya. The main objective is to determine whether migration and remittances contribute to the development of agriculture. Our results suggest that most migrants are pushed out of rural areas, belong to the group of low-paid workers in urban areas, send little and irregular remittances to their wives back in rural areas and that these remittances are mainly used for consumption purposes and do not contribute to any significant development in agriculture. Our results also indicate that altruism or social obligation might be the main reason for migrants sending remittances back to their rural wives.

Robust parameter settings of evolutionary algorithms for the optimisation of agricultural systems models

Numerical optimisation methods are being more commonly applied to agricultural systems models, to identify the most profitable management strategies. The available optimisation algorithms are reviewed and compared, with literature and our studies identifying evolutionary algorithms (including genetic algorithms) as superior in this regard to simulated annealing, tabu search, hill-climbing, and direct-search methods. Results of a complex beef property optimisation, using a real-value genetic algorithm, are presented. The relative contributions of the range of operational options and parameters of this method are discussed, and general recommendations listed to assist practitioners applying evolutionary algorithms to the solution of agricultural systems. (C) 2001 Elsevier Science Ltd. All rights reserved.

Foraging by the endangered black-breasted button-quail (Turnix melanogaster) within fragmented rainforest of an agricultural landscape

We studied the foraging habitat of the endangered black-breasted button-quail (Turnix melanogaster) in 13 rainforest patches of an agricultural landscape (23.4 km(2)) in eastern Australia to assess its use of fragmented habitats outside conservation reserves. The species foraged only in the three largest patches (17.4, 40.0, 63.8 ha in size), all of which were connected to open eucalypt forest, and in intact rainforest. Occurrence of birds was greatest in the largest patch. The maximum number of individuals within the study area was estimated to be 22. Radio-tracking of nine birds revealed that three were resident in the largest patch for periods of over 100 days; no movements between patches were detected. Three radio-tagged birds were taken by avian and mammalian predators. Our results indicated that the long-term future of the species in agricultural landscapes is bleak and that management action is urgently needed to arrest its decline in these ecosystems, (C) 2001 Elsevier Science Ltd. All rights reserved.