Native cut foliage production using Proteaceae species - A research summary

The Queensland Department of Primary Industries and Fisheries in collaboration with the Rural Industries Research and Development Corporation and Yuruga Nursery Pty Ltd have been conducting research into the development of five native foliage products. The three species and two cultivars being developed for commercial production are: Grevillea baileyana, Lomatia fraxinifolia, Athertonia diversifolia, Stenocarpus 'Forest Lace' and Stenocarpus 'Forest Gem'. Previous research involved an evaluation of 21 species from which these five were selected based on market comments, post harvest life and ability to grow under a range of climatic conditions. Lomatia fraxinifolia, Grevillea baileyana and Athertonia diversifolia are all native to north Queensland rainforests. Stenocarpus 'Forest Gem' and Stenocarpus 'Forest Lace' are hybrids and have been selected by Yuruga Nursery Pty Ltd. Both Stenocarpus cultivars are protected by Plant Breeders Rights. Current research into the commercial development of these species involves: market research, post harvest trials, field trials and grower training. Two field trials have been established on the Atherton Tablelands, one in the high rainfall zone at Yungaburra and the other in the low rainfall zone west of Mareeba. Field trials will evaluate the effects of fertiliser rates and pruning techniques on yield. Pests and diseases will be identified and appropriate control measures tested on trial plants. Vase life evaluations have also been carried out and the results indicate that the five foliages have exceptional vase life. All five products are being sold on the Australian domestic market in small volumes at this stage; it is anticipated that sales will significantly increase in the coming years. A number of leading exporters have indicated that the foliages may also meet the requirements of export markets. Stenocarpus 'Forest Gem' is similar in appearance to Persoonia longifolia (Barker Bush), which is a bush-picked foliage currently exported from Australia to a number of overseas markets.

Beyond chemical dependency for managing plant-parasitic nematodes: Examples from the banana, pineapple and vegetable industries of tropical and subtropical Australia

Plant-parasitic nematodes are important pests of horticultural crops grown in tropical and subtropical regions of Australia. Burrowing nematode (Radopholus similis) is a major impediment to banana production and root-knot nematodes (predominantly Meloidogyne javanica and M. incognita) cause problems on pineapple and a range of annual vegetables, including tomato, capsicum, zucchini, watermelon, rockmelon, potato and sweet potato. In the early 1990s, nematode control in these industries was largely achieved with chemicals, with methyl bromide widely used on some subtropical vegetable crops, ethylene dibromide applied routinely to pineapples and non-volatile nematicides such as fenamiphos applied up to four times a year in banana plantations. This paper discusses the research and extension work done over the last 15 years to introduce an integrated pest management approach to nematode control in tropical and subtropical horticulture. It then discusses various components of current integrated pest management programs, including crop rotation, nematode monitoring, clean planting material, organic amendments, farming systems to enhance biological suppression of nematodes and judicious use of nematicides. Finally, options for improving current management practices are considered.

Ceratocystis atrox sp. nov. associated with Phoracantha acanthocera infestations on Eucalyptus grandis in Australia

Ceratocystis spp. include important pathogens of trees as well as apparently saprophytic species. Four species have been recorded on Eucalyptus grandis in Australia, of which only one, C. pirilliformis Barnes and M.J. Wingf., is known to be pathogenic. A recent survey of pests and diseases of Eucalyptus trees in northern Queensland revealed a species of Ceratocystis associated with the tunnels made by the aggressive wood-boring insect Phoracantha acanthocera (Macleay) (Cerambicydae: Coleoptera). The aim of the present study was to identify the fungus based on morphological characteristics and comparisons of DNA sequence data for three gene regions. The fungus peripherally resembles C. fimbriata Ell. and Halst. but differs from this species most obviously by having much darker mycelium, longer ascomatal necks, segmented hyphae and an absence of aleuroconidia. Comparisons of combined sequence data confirmed that the Ceratocystis sp. from P. acanthocera represents an undescribed taxon, which is provided with the name Ceratocystis atrox sp. nov. C. atrox appears to have a close relationship with P. acanthocera, although its role in the biology of the insect is unknown and its pathogenicity has not been considered.

Influence of food supplementation on the fitness of two biological control agents: a predatory nabid bug and a bollworm pupal parasitoid

Many arthropod predators and parasitoids exhibit either stage-specific or lifetime omnivory, in that they include extra-floral nectar, floral nectar, honeydew or pollen in their immature and/or adult diet. Access to these plant-derived foods can enhance pest suppression by increasing both the individual fitness and local density of natural enemies. Commercial products such as Amino-Feed®, Envirofeast®, and Pred-Feed® can be applied to crops to act as artificial-plant-derived foods. In laboratory and glasshouse experiments we examined the influence of carbohydrate and protein rich Amino-Feed UV® or Amino-Feed, respectively, on the fitness of a predatory nabid bug Nabis kinbergii Reuter (Hemiptera: Nabidae) and bollworm pupal parasitoid Ichneumon promissorius (Erichson) (Hymenoptera: Ichneumonidae). Under the chosen conditions, the provision of either wet or dry residues of Amino-Feed UV had no discernable effect on immediate or longer-term survival and immature development times of N. kinbergii. In contrast, the provision of honey, Amino-Feed plus extrafloral nectar, and extrafloral nectar alone had a marked effect on the longevity of I. promissorius, indicating that they were limited by at least carbohydrates as an energy source, but probably not protein. Compared with a water only diet, the provision of Amino-Feed plus extrafloral nectar increased the longevity of males and females of I. promissorius by 3.0- and 2.4-fold, respectively. Not only did female parasitoids live longer when provided food, but the total number of eggs laid and timing of deposition was affected by diet under the chosen conditions. Notably, females in the water and honey treatments deposited greater numbers of eggs earlier in the trial, but this trend was unable to be sustained over their lifetime. Egg numbers in these treatments subsequently fell below the levels achieved by females in the Amino-Feed plus extrafloral nectar and cotton extrafloral nectar only treatments. Furthermore, there were times when the inclusion of the Amino-Feed was beneficial compared with cotton extrafloral nectar only. Artificial food supplements and plant-derived foods are worthy of further investigation because they have potential to improve the ecosystem service of biological pest control in targeted agroecosystems by providing natural enemies with an alternative source of nutrition, particularly during periods of prey/host scarcity.

Optimising indoor phosphine fumigation of paddy rice bag-stacks under sheeting for control of resistant insects

Three indoor, sheeted bag-stack fumigations of paddy rice using aluminium phosphide were undertaken in Guangdong Province, southern China. We measured the effect of two types of sheeting (polyvinylchloride [PVC] or polyethylene [PE]) and two types of floor sealing (clips or fixing into a slot with a rubber pipe) on phosphine concentration and retention. The aim was to test the feasibility of retaining fumigant at a sufficient concentration for long enough to control known resistant insect pests. Each stack was pressure tested and phosphine concentrations measured daily during the fumigation. Cages of test insects in culture medium, including resistant and susceptible strains, were placed inside each stack and could be observed through the clear sheeting. Highest concentrations for the longest period were obtained in a PVC-covered stack that included a ground sheet and wall sheets sealed to the floor with rubber pipes. A similar PVC-covered stack sealed to the floor with clips instead of pipe did not retain gas as efficiently and required re-dosing. A PE-covered stack, with no ground sheet but also with wall sheets sealed to the floor with pipe, produced an acceptable fumigation. Susceptible Rhyzopertha dominica were controlled in 2 days and the most resistant strain in 15 days. Resistant Cryptolestes ferrugineus survived until day 21. The paddy was still free of insect infestation 7 months later when the bag-stack was opened to mill the rice. Pressure half-lives correlated with gas concentration and retention. Sorption appeared to be a major limiting factor, reducing potential fumigant dosage by about 50%. The trials demonstrated the feasibility of sealing bag-stacks to a standard high enough to control all known resistant strains.

Global trade in ornamental fish from an Australian perspective: The case for revised import risk analysis and management strategies

Over 1 billion ornamental fish comprising more than 4000 freshwater and 1400 marine species are traded internationally each year, with 8-10 million imported into Australia alone. Compared to other commodities, the pathogens and disease translocation risks associated with this pattern of trade have been poorly documented. The aim of this study was to conduct an appraisal of the effectiveness of risk analysis and quarantine controls as they are applied according to the Sanitary and Phytosanitary (SPS) agreement in Australia. Ornamental fish originate from about 100 countries and hazards are mostly unknown; since 2000 there have been 16-fold fewer scientific publications on ornamental fish disease compared to farmed fish disease, and 470 fewer compared to disease in terrestrial species (cattle). The import quarantine policies of a range of countries were reviewed and classified as stringent or non-stringent based on the levels of pre-border and border controls. Australia has a stringent policy which includes pre-border health certification and a mandatory quarantine period at border of 1-3 weeks in registered quarantine premises supervised by government quarantine staff. Despite these measures there have been many disease incursions as well as establishment of significant exotic viral, bacterial, fungal, protozoal and metazoan pathogens from ornamental fish in farmed native Australian fish and free-living introduced species. Recent examples include Megalocytivirus and Aeromonas salmonicida atypical strain. In 2006, there were 22 species of alien ornamental fish with established breeding populations in waterways in Australia and freshwater plants and molluscs have also been introduced, proving a direct transmission pathway for establishment of pathogens in native fish species. Australia's stringent quarantine policies for imported ornamental fish are based on import risk analysis under the SPS agreement but have not provided an acceptable level of protection (ALOP) consistent with government objectives to prevent introduction of pests and diseases, promote development of future aquaculture industries or maintain biodiversity. It is concluded that the risk analysis process described by the Office International des Epizooties under the SPS agreement cannot be used in a meaningful way for current patterns of ornamental fish trade. Transboundary disease incursions will continue and exotic pathogens will become established in new regions as a result of the ornamental fish trade, and this will be an international phenomenon. Ornamental fish represent a special case in live animal trade where OIE guidelines for risk analysis need to be revised. Alternatively, for countries such as Australia with implied very high ALOP, the number of species traded and the number of sources permitted need to be dramatically reduced to facilitate hazard identification, risk assessment and import quarantine controls. Lead papers of the eleventh symposium of the International Society for Veterinary Epidemiology and Economics (ISVEE), Cairns, Australia

Effects of rootstock and nitrogen fertiliser on postharvest anthracnose development in Hass avocado

These rootstock and nitrogen fertiliser studies confirmed that rootstock race can significantly affect the development of postharvest disease and mineral nutrient accumulation in Hass avocado fruit. When Hass (Guatemalan race) was grafted to seedling Velvick (West Indian race) rootstock, the severity and incidence of anthracnose in fruit were significantly reduced by up to 64 and 37%, respectively, compared with seedling Duke 6 (Mexican race) rootstock. Stem-end rot was also influenced by rootstock in some seasons, and significant reductions (up to 87%) in the severity and incidence of stem-end rot were recorded in Hass fruit from Velvick compared with Duke 6 rootstock trees. These improvements in postharvest diseases were associated with significantly lower concentrations of nitrogen and potassium, higher concentrations of calcium and magnesium, lower ratios of nitrogen:calcium and higher ratios of calcium + magnesium:potassium in Hass leaves and fruit from Velvick compared with Duke 6 rootstock trees. Altering the rate of nitrogen fertiliser had minimal impact on postharvest disease development. However, in one season, reducing the rate of nitrogen fertiliser to nil significantly reduced the concentration of nitrogen in the fruit skin, decreased the nitrogen:calcium ratio and significantly reduced the severity and incidence of anthracnose in Hass fruit from both Velvick and Duke 6 rootstock trees. The form of nitrogen fertiliser (ammonium compared with nitrate) applied to the trees did not significantly affect the postharvest disease susceptibility of Hass avocado fruit on either Velvick or Duke 6 rootstock. The Guatemalan race rootstocks, Anderson 8 and Anderson 10, were also found to be superior to the Mexican race rootstock, Parida 1, for reducing anthracnose severity. This again, was associated with a better balance of mineral nutrients (significantly lower nitrogen:calcium and higher calcium + magnesium:potassium ratios) in the fruit. This rootstock effect, however, was only observed in the first season of a 3-year experiment, possibly because of a better balance between vegetative growth and fruit production in Parida 1 in the latter two seasons. Significant positive correlations between anthracnose severity and fruit skin nitrogen:calcium ratios were evident across all experiments.

Using morphological traits to identify persistent lucernes for dryland agriculture in NSW, Australia

This paper reports on several studies conducted to better understand the variability between lucerne cultivars and lines, and use this to predict persistence in dryland grazing pastures in eastern Australia. Morphological traits of 20 cultivars/lines were measured in irrigated and dryland spaced plant experiments. Studies were also conducted to describe variation among lucernes in their utilisation of starch and responses to water deficit, pests and diseases. Multiple regression analyses were used to develop simple models where the measured traits could be used to predict persistence of lucerne lines in dryland evaluation experiments. Although there was significant variation among cultivars/lines in most measured traits, no single trait reliably predicted persistence of cultivars/lines in dryland evaluation experiments. However, variation in persistence at both sites could be explained by models developed by multiple regression using differences in the mean lengths of the longest stems at 10% flower in summer and winter. Persistent lucernes were those that had relatively long stems in summer and short stems in winter. Water use efficiencies, starch utilisation patterns and resistances to pests and diseases of different lucernes provided some improvement to this simple model, but these improvements were not consistent.

An overview of integrated pest management (IPM) in north-eastern Australian grain farming systems: Past, present and future prospects

The authors overview integrated pest management (IPM) in grain crops in north-eastern Australia, which is defined as the area north of latitude 32°S. Major grain crops in this region include the coarse grains (winter and summer cereals), oilseeds and pulses. IPM in these systems is complicated by the diversity of crops, pests, market requirements and cropping environments. In general, the pulse crops are at greatest risk, followed by oilseeds and then by cereal grains. Insecticides remain a key grain pest management tool in north-eastern Australia. IPM in grain crops has benefited considerably through the increased adoption of new, more selective insecticides and biopesticides for many caterpillar pests, in particular Helicoverpa spp. and loopers, and the identification of pest-crop scenarios where spraying is unnecessary (e.g. for most Creontiades spp. populations in soybeans). This has favoured the conservation of natural enemies in north-eastern Australia grain crops, and has arguably assisted in the management of silverleaf whitefly in soybeans in coastal Queensland. However, control of sucking pests and podborers such as Maruca vitrata remains a major challenge for IPM in summer pulses. Because these crops have very low pest-damage tolerances and thresholds, intervention with disruptive insecticides is frequently required, particularly during podfill. The threat posed by silverleaf whitefly demands ongoing multi-pest IPM research, development and extension as this pest can flare under favourable seasonal conditions, especially where disruptive insecticides are used injudiciously. The strong links between researchers and industry have facilitated the adoption of IPM practices in north-eastern Australia and augers well for future pest challenges and for the development and promotion of new and improved IPM tactics.

Host plant resistance in grain crops and prospects for invertebrate pest management in Australia: An overview

An integrated pest management (IPM) approach that relies on an array of tactics is adopted commonly in response to problems with pesticide-based production in many agricultural systems. Host plant resistance is often used as a fundamental component of an IPM system because of the generally compatible, complementary role that pest-resistant crops play with other tactics. Recent research and development in the resistance of legumes and cereals to aphids, sorghum midge resistance, and the resistance of canola varieties to mite and insect pests have shown the prospects of host plant resistance for developing IPM strategies against invertebrate pests in Australian grain crops. Furthermore, continuing advances in biotechnology provide the opportunity of using transgenic plants to enhance host plant resistance in grains.

Forest health surveillance methodology in hardwood plantations in Queensland, Australia

Forest health surveillance (FHS) of hardwood plantations commenced in Queensland in 1997 as plantations expanded following a state government planting initiative arising from the national 2020 forest policy vision. The estate was initially characterised by a large number of small plantations (10-50 ha), although this has changed more recently with the concentration of larger plantations in the central coast and South Burnett regions. Due to the disparate nature of the resource, drive- and walkthrough surveys of subsets of plantations have been undertaken in preference to aerial surveys. FHS has been effective in detecting a number of new hardwood pests in Queensland including erinose mites (Rhombacus and Acalox spp.), western white gum plate galler (Ophelimus sp.), Creiis psyllid and bronzing bug (Thaumastocoris sp.), in evaluating their potential impact and assisting in focussing future research efforts. Since 2003 there has been an increased emphasis on training operational staff to take a greater role in identifying and reporting on forest health issues. This has increased their awareness of forest health issues, but their limited time to specifically survey and report on pests and diseases, and high rates of staff turnover, necessitate frequent ongoing training. Consequently, common and widespread problems such as quambalaria shoot blight (Quambalaria pitereka), chrysomelid leaf beetles (mainly Paropsis atomaria) and erinose mites may be under-reported or not reported, and absence data may often not be recorded at all. Comment is made on the future directions that FHS may take in hardwood plantations in Queensland.

The mortality of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) neonate larvae in relation to drop-off and soil surface temperature: The dangers of bungy jumping

The first larval instar has been identified as a critical stage for population mortality in Lepidoptera, yet due to the body size of these larvae, the factors that contribute to mortality under field conditions are still not clear. Dispersal behaviour has been suggested as a significant, but ignored factor contributing to mortality in first-instar lepidopteran larvae. The impact that leaving the host plant has on the mortality rate of Helicoverpa armigera neonates was examined in field crops and laboratory trials. In this study the following are examined: (1) the effects of soil surface temperature, and the level of shade within the crop, on the mortality of neonates on the soil after dropping off from the host plant; (2) the percentage of neonates that dropped off from a host plant and landed on the soil; and (3) the effects of exposure to different soil surface temperatures on the development and mortality of neonates. The findings of this study showed that: (1) on the soil, surface temperatures above 43°C were lethal for neonates, and exposure to these temperatures contributed greatly to the overall mortality rate observed; however, the fate of neonates on the soil varied significantly depending on canopy closure within the crop; (2) at least 15% of neonates dropped off from the host plant and landed on the soil, meaning that the proportion of neonates exposed to these condition is not trivial; and (3) 30 min exposure to soil surface temperatures approaching the lethal level (>43°C) has no significant negative effects on the development and mortality of larvae through to the second instar. Overall leaving the plant through drop-off contributes to first-instar mortality in crops with open canopies; however, survival of neonates that have lost contact with a host plant is possible, and becomes more likely later in the crop growing season.

Development of hazard site surveillance programs for forest invasive species: A case study from Brisbane, Australia

Hazard site surveillance is a system for post-border detection of new pest incursions, targeting sites that are considered potentially at high risk of such introductions. Globalisation, increased volumes of containerised freight and competition for space at domestic ports means that goods are increasingly being first opened at premises some distance from the port of entry, thus dispersing risk away from the main inspection point. Hazard site surveillance acts as a backstop to border control to ensure that new incursions are detected sufficiently early to allow the full range of management options, including eradication and containment, to be considered. This is particularly important for some of the more cryptic forest pests whose presence in a forest often is not discovered until populations are already high and the pest is well established. General requirements for a hazard site surveillance program are discussed using a program developed in Brisbane, Australia, in 2006 as a case study. Some early results from the Brisbane program are presented. In total 67 species and 5757 individuals of wood-boring beetles have been trapped and identified during the program to date. Scolytines are the most abundant taxa, making up 83% of the catch. No new exotics have been trapped but 19 of the species and 60% of all specimens caught are exotics that are already established in Australia.

Thermal requirements, field mortality and population phenology modelling of Paropsis atomaria Olivier, an emergent pest in subtropical hardwood plantations

Paropsis atomaria is a recently emerged pest of eucalypt plantations in subtropical Australia. Its broad host range of at least 20 eucalypt species and wide geographical distribution provides it the potential to become a serious forestry pest both within Australia and, if accidentally introduced, overseas. Although populations of P. atomaria are genetically similar throughout its range, population dynamics differ between regions. Here, we determine temperature-dependent developmental requirements using beetles sourced from temperate and subtropical zones by calculating lower temperature thresholds, temperature-induced mortality, and day-degree requirements. We combine these data with field mortality estimates of immature life stages to produce a cohort-based model, ParopSys, using DYMEX™ that accurately predicts the timing, duration, and relative abundance of life stages in the field and number of generations in a spring–autumn (September–May) field season. Voltinism was identified as a seasonally plastic trait dependent upon environmental conditions, with two generations observed and predicted in the Australian Capital Territory, and up to four in Queensland. Lower temperature thresholds for development ranged between 4 and 9 °C, and overall development rates did not differ according to beetle origin. Total immature development time (egg–adult) was approximately 769.2 ± S.E. 127.8 DD above a lower temperature threshold of 6.4 ± S.E. 2.6 °C. ParopSys provides a basic tool enabling forest managers to use the number of generations and seasonal fluctuations in abundance of damaging life stages to estimate the pest risk of P. atomaria prior to plantation establishment, and predict the occurrence and duration of damaging life stages in the field. Additionally, by using local climatic data the pest potential of P. atomaria can be estimated to predict the risk of it establishing if accidentally introduced overseas. Improvements to ParopSys’ capability and complexity can be made as more biological data become available.

Specimen-based databases of Australian plant pathogens: past, present and future

Specimen-based records of most of the plant pathogens that occur in Australia can be accessed through the Australian Plant Disease Database and the Australian Plant Pest Database. These databases and the herbaria that underpin them are important resources for resolving quarantine and trade issues as well as for the diagnosis of plant diseases. The importance of these collections and databases to Australia's agricultural industries is discussed.