Obituary: Michael Edwards

I first met Michael about forty years ago. At the time those of us involved in art therapy were forming a professional body which became the British Association of Art Therapists, activities like this bring people with common interests together who otherwise might never have met and this happened with Michael and I. Another related connection with Michael was the ”˜Education through Art’ movement which held great sway in the 1960s and 70s. The central idea in the movement was that art and aesthetic experience were pivotal in all learning and teaching, not a holiday away from ”˜real’ experience, but at the heart of living itself. In 1970 the International Society for Education Through Art held its Congress at Coventry in the UK, I ran a workshop at this gathering and Michael joined it. I enjoyed working with him, I thought he was modest about himself and I later came to see that one of his gifts was not to ”˜blow his own trumpet’ so to speak, an image I will return to, but to help people he was involved with to find out how they really wanted to be

Priorities and Strategies for Soil and Water Aspects of Natural Resources Management Research in the CGIAR

Report of a TAC study on priorities for the soil and water aspects of research on natural resource management (NRM) research in the CGIAR, completed in April 1996 under the leadership of TAC members Hans Gregersen and Ted Henzell. The study is supported by background reports on a strategic review of NRM research on soil and water, and a synthesis of current activities in soil and water research in the CGIAR. The document also contains an extract from the proceedings of the CGIAR meeting in May 1996, and a transmittal from the TAC Chairman.The paper conveys TAC's views on the needs for soil and water research in the CGIAR and the mechanisms for meeting those needs. It says that strengthening research on environmental issues is needed, but linked to the CGIAR vision of contributing to poverty alleviation and sustainable food security. Other goals of NRM research should be considered as well. The balance of effort should be shifted from location specific studies to results transferable among developing countries. The centers should play an active but limited role in generating information on the condition of the natural environment, and the impact of humans on that environment. The CGIAR needed an integrated framework for NRM research, and within that framework to focus on specific subject matter. Water in particular was cited as needing more emphasis. The paper called for uniform and consistent criteria for judging CGIAR priorities for NRM activities and research. The study was requested by the Group at the CGIAR Mid Term Meeting, May 1994, and was initiated at TAC 65 in October 1994. The evolving study was considered at TAC 66, 67, 68, and 69. It was presented at the CGIAR Mid Term Meeting in May 1996

Does maintaining green leaf area in sorghum improve yield under drought? II. Dry matter production and yield

Retention of green leaf area at maturity (GLAM), known as stay-green, is used as an indicator of postanthesis drought resistance in sorghum [Sorghum bicolor (L.) Moench] breeding programs in the USA and Australia. The critical issue is whether maintaining green leaves under postanthesis drought increases grain yield in stay-green compared with senescent hybrids. Field studies were undertaken in northeastern Australia on a cracking and self-mulching gray clay. Nine closely related hybrids varying in rate of leaf senescence were grown under two water-limiting regimes, post-flowering water deficit and terminal (pre- and postflowering) water deficit, and a fully irrigated control. Under terminal water deficit, grain yield was correlated positively with GLAM (r = 0.75**) and negatively with rate of leaf senescence (r = -0.74**). Grain yield also increased by ≃0.35 Mg ha-1 for every day that onset of leaf senescence was delayed beyond 76 DAE in the water-limited treatments. Stay-green hybrids produced 47% more postanthesis biomass than their senescent counterparts (920 vs. 624 g m-2) under the terminal water deficit regime. No differences in grain yield were found among eight of the nine hybrids under fully irrigated conditions, suggesting that the stay-green trait did not constrain yield in the well-watered control. The results indicate that sorghum hybrids possessing the stay-green trait have a significant yield advantage under postanthesis drought compared with hybrids not possessing this trait

On the relation between weather variables and sorghum ergot infection

Sorghum ergot (Claviceps africana) has had a significant impact on seed production and breeders’ nurseries in Australia since it was first found in 1996. In this paper, 3 distinct key development stages of sorghum that are related to ergot infection were identified: flag leaf stage, pollen starch accumulation stage, and flowering period. Relationships between weather variables during these 3 stages and ergot severity as well as pollen viability were analysed using observed data from 2 field trials, a serial planting trial and a genotype trial, conducted at Gatton, Queensland. The duration of the flag leaf stage and of the flowering period was estimated from thermal time. An infection factor was introduced and calculated based on hourly temperature during the flowering period. This infection factor and the mean relative humidity at 0900 hours during the flowering period were the main factors influencing ergot infection. Mean daily minimum temperature during flag leaf stage also had a significant effect on ergot severity, although no significant relation was found between this mean daily minimum temperature and pollen viability. A linear regression model using the above 3 factors accounted for 94% of the environmentally caused variation in ergot severity observed in the genotype trial

Energy Expenditure of Grade Four School Children in Western Australia

A composite team from the Public Health Service, the West Australian Institute of Technology, and the Graylands Teachers College conducted surveys on grade 7 children in 1974, and grade 4 children in 1975. The intention of the surveys was to find some relationship between the energy expenditure and the energy intake of each age group. As there is little information concerning the activity patterns of West Australian children the findings of these surveys would serve as a basis for more detailed reports into the physical fitness, activity and dietary balance of children in today\u27s changing society. The study reported below is of the 1975 survey conducted on grade 4 children

Two distinct classes of QTL determine rust resistance in sorghum

Background: Agriculture is facing enormous challenges to feed a growing population in the face of rapidly evolving pests and pathogens. The rusts, in particular, are a major pathogen of cereal crops with the potential to cause large reductions in yield. Improving stable disease resistance is an on-going major and challenging focus for many plant breeding programs, due to the rapidly evolving nature of the pathogen. Sorghum is a major summer cereal crop that is also a host for a rust pathogen which occurs in almost all sorghum growing areas of the world, causing direct and indirect yield losses in sorghum worldwide, however knowledge about its genetic control is still limited. In order to further investigate this issue, QTL and association mapping methods were implemented to study rust resistance in three bi-parental populations and an association mapping set of elite breeding lines in different environments. Results: In total, 64 significant or highly significant QTL and 21 suggestive rust resistance QTL were identified representing 55 unique genomic regions. Comparisons across populations within the current study and with rust QTL identified previously in both sorghum and maize revealed a high degree of correspondence in QTL location. Negative phenotypic correlations were observed between rust, maturity and height, indicating a trend for both early maturing and shorter genotypes to be more susceptible to rust. Conclusions: The significant amount of QTL co-location across traits, in addition to the consistency in the direction of QTL allele effects, has provided evidence to support pleiotropic QTL action across rust, height, maturity and stay-green, supporting the role of carbon stress in susceptibility to rust. Classical rust resistance QTL regions that did not co-locate with height, maturity or stay-green QTL were found to be significantly enriched for the defence-related NBS-encoding gene family, in contrast to the lack of defence-related gene enrichment in multi-trait effect rust resistance QTL. The distinction of disease resistance QTL hot-spots, enriched with defence-related gene families from QTL which impact on development and partitioning, provides plant breeders with knowledge which will allow for fast-tracking varieties with both durable pathogen resistance and appropriate adaptive traits

Understanding lolium rigidum seeds: The key to managing a problem weed?

The 40 million hectare southern Australian winter cropping region suffers from widespread infestation by Lolium rigidum (commonly known as annual or rigid ryegrass), a Mediterranean species initially introduced as a pasture plant. Along with its high competitiveness within crops, rapid adaptability and widespread resistance to herbicides, the dormancy of its seeds means that L. rigidum is the primary weed in southern Australian agriculture. With the individuals within a L. rigidum population exhibiting varying levels of seed dormancy, germination can be staggered across the crop-growing season, making complete weed removal virtually impossible, and ensuring that the weed seed bank is constantly replenished. By understanding the processes involved in induction and release of dormancy in L. rigidum seeds, it may be possible to develop strategies to more effectively manage this pest without further stretching herbicide resources. This review examines L. rigidum seed dormancy and germination from a weed-management perspective and explains how the seed bank can be depleted by control strategies encompassing all stages in the lifecycle of a seed, from development to germination

Trends in Numbers and Changes in the Distribution of Feral Goats (Capra Hircus) in the South Australian Pastoral Zone

Trends in numbers and changes in the distribution of feral goats in the South Australian pastoral zone (217,300 km2) during 1978-94 were determined by winter aerial surveys. Only the presence or absence of goats on sample units was scored between 1978 and 1988. On the assumption of a random distribution of goat groups, these indices were transformed to densities of goat groups. Between 1989 and 1994 actual goat numbers were recorded on each sample unit, allowing goat density to be estimated. Goats were consistently at their highest densities in the south-east of the pastoral zone, a region dominated by open mallee scrub and chenopod shrubland. Densities of goat groups fluctuated from a low in 1984, following a drought, to a peak in 1990, following above-average rainfalls, when there were an estimated 193,700 - 29,600 goats in the pastoral zone. This estimate is conservative because it is uncorrected for the visibility bias associated with sighting groups and undercounting their sizes. The estimate also excludes the Flinders Ranges for which a similar number of goats has been estimated