Infochemistry for pest management in plant crops

The development of integrated pest and disease management strategies have been a major research focus for DEEDI in the cropping, horticulture and forestry industries for many years.

Banana Plant Protection Program

Developing a National Banana Plant Protection Program four key strategic areas have been identified which each address a number of key strategic objectives. Taken together they address the key strategic objectives as outlined in the strategic plan. The four key strategic areas of the Plant Protection Program are: 1. Resistant Varieties and Consumer Choice; 2. Safeguarding Production and Markets; 3. Sustainable Production Systems; 4. Building Science and Communication.

Controlling plant and fruit diseases in strawberry fields

Grey mould, powdery mildew and stem-end rot are major diseases affecting the strawberry industry. Some of the chemicals used are ineffective under wet weather, have limits to the number of applications allowed in a season or may become ineffective in the long-term because of the development of resistance in the fungi. We will assess the effectiveness of the chemicals currently used by the strawberry industry and whether the fruit rot fungi are resistant to these fungicides. We will screen other chemicals that are used to control these diseases in related crops. We will also evaluate new chemicals in collaboration with the crop protectant industry. We will also undertake similar work to control nematodes in strawberry fields.

CRC27012 A National Diagnostic Database for Emergency Plant Pests

Development of a national diagnostic database for Emergency Plant Pests which will be web-accessible.

CRC40142 Defining the plant pathogen risk posed by international travellers

This project will define the plant pathogen incursion risk posed by people returning from overseas and interstate travel. This will be achieved through the development of technically sound sample/survey methodologies. The project will initially focus on cereal rusts. An assessment of the current level of human mediated rust entries into Australia will be determined through the sampling of travellers who have been known to have visited grain production regions overseas.

Post Entry Plant Quarantine

The seeds of the majority of commercial crops must be grown for one generation in post-entry plant quarantine on arrival in Australia. Live plants and cuttings must also undergo quarantine screening on arrival, and spend a minimum of three months in quarantine.

205-14 A Monograph of the plant-infecting members of the Order Clavicipitales in

Taxonomic revision of ergots and related fungi in Australia.

Hierarchical Bayesian modelling of early detection surveillance for plant pest invasions

Early detection surveillance programs aim to find invasions of exotic plant pests and diseases before they are too widespread to eradicate. However, the value of these programs can be difficult to justify when no positive detections are made. To demonstrate the value of pest absence information provided by these programs, we use a hierarchical Bayesian framework to model estimates of incursion extent with and without surveillance. A model for the latent invasion process provides the baseline against which surveillance data are assessed. Ecological knowledge and pest management criteria are introduced into the model using informative priors for invasion parameters. Observation models assimilate information from spatio-temporal presence/absence data to accommodate imperfect detection and generate posterior estimates of pest extent. When applied to an early detection program operating in Queensland, Australia, the framework demonstrates that this typical surveillance regime provides a modest reduction in the estimate that a surveyed district is infested. More importantly, the model suggests that early detection surveillance programs can provide a dramatic reduction in the putative area of incursion and therefore offer a substantial benefit to incursion management. By mapping spatial estimates of the point probability of infestation, the model identifies where future surveillance resources can be most effectively deployed.

Plant based monitoring for irrigation scheduling in vegetable horticulture: A case study in South Australian onions

Direct measurement of plant water status for irrigation scheduling may be more sensitive, and promote better horticultural crop quality, than indirect methods such as soil moisture monitoring. In our research project, we sought to identify instances where direct methods of plant-water status previously used in horticultural crops in Australia. We present the outcomes, suitability or obstacles for adoption by horticultural producers.

The DOOR manual for plant nurseries

In the nursery industry, generic research conducted by government institutions is often not specific enough to be highly valued and adopted by the individual operator. Operators need practical solutions to their particular problems. Such problems almost invariably involve sets of conditions common to few other enterprises. This uniqueness reflects the almost infinite variation of options available in terms of species grown, media used, fertiliser, amendments and chemicals applied and the way water is supplied. The DOOR (Do Our Own Research) method advocates a relatively unexplored way of generating new, statistically sound research information in the nursery industry. The manual aims to enhance nursery operators' understanding and skills development in the following areas: critially evaluating opportunities and problems in the nursery environment, gathering relevant information, deriving and prioritising potential solutions to problems and opportunities, becoming familiar with the scientific method employed in testing potential solutions, carrying out statistically sound aand rigorous research, and developing recommendations that flow from the research information generated. The DOOR approach has application in a number of other industries and may provide important support at a time of declining research, development and extension investment by the public sector.

The biology of Australian weeds 58. Baccharis halimifolia L.

Review of the biology of the Australian weed Baccharis halimifolia. This paper reviews the morphology, geographical distribution, habitat, growth and development, reproduction (flowering, seed production and dispersal, and seed germination), hybrids, population dynamics, importance (detrimental and beneficial), legislation, and control (using mechanical methods, herbicides and biological control agents/natural enemies) of an invasive alien species, B. shall.

Phosphonate applied as a pre-plant dip controls Phytophthora cinnamomi root and heart rot in susceptible pineapple hybrids.

The effectiveness of pre-plant dips of crowns in potassium phosphonate and phosphorous acid was investigated in a systematic manner to develop an effective strategy for the control of root and heart rot diseases caused by Phytophthora cinnamomi in the pineapple hybrids 'MD2' and '73-50' and cultivar Smooth Cayenne. Our results clearly indicate that a high volume spray at planting was much less effective when compared to a pre-plant dip. 'Smooth Cayenne' was found to be more resistant to heart rot than 'MD2' and '73-50', and 'Smooth Cayenne' to be more responsive to treatment with potassium phosphonate. Based on cumulative heart rot incidence over time 'MD2' was more susceptible to heart rot than '73-50' and was more responsive to an application of phosphorous acid. The highest levels of phosphonate in roots were reached one month after planting and levels declined during the next two months. Pre-plant dipping of crowns prior to planting is highly effective to control root and heart rot in the first few months but is not sufficient to maintain health of the mother plant root system up until plant crop harvest when weather conditions continue to favour infection.

Is prosopis a curse or a blessing? : An ecological economic analysis of an invasive alien tree species in Sudan.

The issue of the usefulness of different prosopis species versus their status as weeds is a matter of hot debate around the world. The tree Prosopis juliflora had until 2000 been proclaimed weedy in its native range in South America and elsewhere in the dry tropics. P. juliflora or mesquite has a 90-year history in Sudan. During the early 1990s a popular opinion in central Sudan and the Sudanese Government had begun to consider prosopis a noxious weed and a problematic tree species due to its aggressive ability to invade farmlands and pastures, especially in and around irrigated agricultural lands. As a consequence prosopis was officially declared an invasive alien species also in Sudan, and in 1995 a presidential decree for its eradication was issued. Using a total economic valuation (TEV) approach, this study analysed the impacts of prosopis on the local livelihoods in two contrasting irrigated agricultural schemes. Primarily a problem-based approach was used in which the derivation of non-market values was captured using ecological economic tools. In the New Halfa Irrigation Scheme in Kassala State, four separate household surveys were conducted due to diversity between the respective population groups. The main aim was here to study the magnitude of environmental economic benefits and costs derived from the invasion of prosopis in a large agricultural irrigation scheme on clay soil. Another study site, the Gandato Irrigation Scheme in River Nile State represented impacts from prosopis that an irrigation scheme was confronted with on sandy soil in the arid and semi-arid ecozones along the main River Nile. The two cases showed distinctly different effects of prosopis but both indicated the benefits to exceed the costs. The valuation on clay soil in New Halfa identified a benefit/cost ratio of 2.1, while this indicator equalled 46 on the sandy soils of Gandato. The valuation results were site-specific and based on local market prices. The most important beneficial impacts of prosopis on local livelihoods were derived from free-grazing forage for livestock, environmental conservation of the native vegetation, wood and non-wood forest products, as well as shelterbelt effects. The main social costs from prosopis were derived from weeding and clearing it from farm lands and from canalsides, from thorn injuries to humans and livestock, as well as from repair expenses vehicle tyre punctures. Of the population groups, the tenants faced most of the detrimental impacts, while the landless population groups (originating from western and eastern Sudan) as well as the nomads were highly dependent on this tree resource. For the Gandato site the monetized benefit-cost ratio of 46 still excluded several additional beneficial impacts of prosopis in the area that were difficult to quantify and monetize credibly. In River Nile State the beneficial impact could thus be seen as completely outweighing the costs of prosopis. The results can contributed to the formulation of national and local forest and agricultural policies related to prosopis in Sudan and also be used in other countries faced with similar impacts caused by this tree.

Influence of plant traits on production costs and profitability of strawberry in southeast Queensland.

In Queensland the subtropical strawberry ( Fragaria * ananassa) breeding program aims to combine traits into novel genotypes that increase production efficiency. The contribution of individual plant traits to cost and income under subtropical Queensland conditions was investigated, with the overall goal of improving the profitability of the industry through the release of new strawberry cultivars. The study involved specifying the production and marketing system using three cultivars of strawberry that are currently widely grown annually in southeast Queensland, developing methods to assess the economic impact of changes to the system, and identifying plant traits that influence outcomes from the system. From May through September P (price; $ punnet -1), V (monthly mass; tonne of fruit on the market) and M (calendar month; i.e. May=5) were found to be related ( r2=0.92) by the function (SE) P=4.741(0.469)-0.001630(0.0005) V-0.226(0.102) M using data from 2006 to 2010 for the Brisbane central market. Both income and cost elements in the gross margin were subject to sensitivity analysis. 'Harvesting' and 'Handling/Packing' 'Groups' of 'Activities' were the major contributors to variable costs (each >20%) in the gross margin analysis. Within the 'Harvesting Group', the 'Picking Activity' contributed most (>80%) with the trait 'display of fruit' having the greatest (33%) influence on the cost of the 'Picking Activity'. Within the 'Handling/Packing Group', the 'Packing Activity' contributed 50% of costs with the traits 'fruit shape', 'fruit size variation' and 'resistance to bruising' having the greatest (12-62%) influence on the cost of the 'Packing Activity'. Non-plant items (e.g. carton purchases) made up the other 50% of the costs within the 'Handling/Packing Group'. When any of the individual traits in the 'Harvesting' and 'Handling/Packing' groups were changed by one unit (on a 1-9 scale) the gross margin changed by up to 1%. Increasing yield increased the gross margin to a maximum (15% above present) at 1320 g plant -1 (94% above present). A 10% redistribution of total yield from September to May increased the gross margin by 23%. Increasing fruit size increased gross margin: a 75% increase in fruit size (to ~30 g) produced a 22% increase in the gross margin. The modified gross margin analysis developed in this study allowed simultaneous estimation of the gross margin for the producer and gross value of the industry. These parameters sometimes move in opposite directions.

Multiple host use by a sap-sucking membracid: population consequences of nymphal development on primary and secondary host plant species

Aconophora compressa is a gregarious, sap-sucking insect that uses multiple host plant species. Nymphal host plant species (and variety) significantly affected nymphal survival, nymphal development rate and the subsequent size and fecundity of adults, with fiddlewood ( Citharexylum spinosum ) being significantly best in all respects. Nymphs that developed on a relatively poor host ( Duranta erecta var “geisha girl”) and which were moved to fiddlewood as adults laid significantly fewer eggs (mean ± SE = 836 ± 130) than those that developed solely on fiddlewood (1,329 ± 105). Adults on geisha girl, regardless of having been reared as nymphs on fiddlewood or geisha girl, laid significantly fewer eggs (342 ± 83 and 317 ± 74, respectively) than adults on fiddlewood. A simple model that incorporates host plant related survival, development rate and fecundity suggests that the population dynamics of A. compressa are governed mainly by fiddlewood, the primary host. The results have general implications for understanding the population dynamics of herbivores that use multiple host plant species, and also for the way in which weed biological control host testing methods should be conducted.