Phenology of Carpophilus spp. (Coleoptera: Nitidulidae)in stone fruit orchards as determined by pheromone trapping: Implications for prediction of crop damage

Traps baited with synthetic aggregation pheromone and fermenting bread dough were used to monitor seasonal incidence and abundance of the ripening fruit pests, Carpophilus hemipterus (L.), C. mutilatus Erichson and C. davidsoni Dobson in stone fruit orchards in the Leeton district of southern New South Wales during five seasons (1991-96). Adult beetles were trapped from September-May, but abundance varied considerably between years with the amount of rainfall in December-January having a major influence on population size and damage potential during the canning peach harvest (late February-March). Below average rainfall in December-January was associated with mean trap catches of < 10 beetles/trap/week in low dose pheromone traps during the harvest period in 1991/92 and 1993/94 and no reported damage to ripening fruit. Rainfall in December-January 1992/93 was more than double the average and mean trap catches ranged from 8-27 beetles/week during the harvest period with substantial damage to the peach crop. December-January rainfall was also above average in 1994/95 and 1995/96 and means of 50-300 beetles/trap/week were recorded in high dose pheromone traps during harvest periods. Carpophilus spp. caused economic damage to peach crops in both seasons. These data indicate that it may be possible to predict the likelihood of Carpophilus beetle damage to ripening stone fruit in inland areas of southern Australia, by routine pheromone-based monitoring of beetle populations and summer temperatures and rainfall.

New microsatellite loci for Carcharhinid sharks (Carcharhinus tilstoni and C. sorrah) and their cross-amplification in other shark species

Twelve microsatellite DNA markers were isolated in the spot-tail shark (Carcharhinus sorrah) and nine were isolated in Australian black-tip shark (Carcharhinus tilstoni). These loci plus 18 others developed for sharks from the genera Negaprion, Ginglymostoma, Carcharodon and Isurus were tested for amplification success on four species of Carcharhinus (including C. sorrah and C. tilstoni) and four other species representing three diverse families. Cross-amplification was most common within families. Five loci were subsequently tested for polymorphism on 50 C. sorrah and 60 C. tilstoni. The number of alleles per locus was two to 24 and the average heterozygosity was 0.54 (range 0.16-0.87) for C. sorrah and 0.64 (range 0.44-0.78) for C. tilstoni. These loci may be useful tools for genetic analyses of the Carcharhinidae.

The introduction and release of Chiasmia inconspicua and C. assimilis (Lepidoptera: Geometridae) for the biological control of Acacia nilotica in Australia

Two geometrid moths Chiasmia inconspicua and Chiasmia assimilis, identified as potential biological control agents for prickly acacia Acacia nilotica subsp. indica, were collected in Kenya and imported into quarantine facilities in Australia where laboratory cultures were established. Aspects of the biologies of both insects were studied and CLIMEX® models indicating the climatically favourable areas of Australia were developed. Host range tests were conducted using an approved test list of 74 plant species and no-choice tests of neonate larvae placed on both cut foliage and potted plants. C. inconspicua developed through to adult on prickly acacia and, in small numbers, Acacia pulchella. C. assimilis developed through to adult on prickly acacia and also in very small numbers on A. pulchella, A. deanei, A. decurrens, and A. mearnsii. In all experiments, the response on prickly acacia could be clearly differentiated from the responses on the non-target species. Both insects were approved for release in Australia. Over a three-year period releases were made at multiple sites in north Queensland, almost all in inland areas. There was no evidence of either insect's establishment and both colonies were terminated. A new colony of C. assimilis was subsequently established from insects collected in South Africa and releases of C. assimilis from this new colony were made into coastal and inland infestations of prickly acacia. Establishment was rapid at one coastal site and the insect quickly spread to other infestations. Establishment at one inland area was also confirmed in early 2006. The establishment in coastal areas supported a CLIMEX model that indicated that the climate of coastal areas was more suitable than inland areas.

Molecular characterisation, pathogenesis and fungicide sensitivity of Pythium spp. from table beet (Beta vulgaris var. vulgaris) grown in the Lockyer Valley, Queensland

Table beet production in the Lockyer Valley of south-eastern Queensland is known to be adversely affected by soilborne root disease from infection by Pythium spp. However, little is known regarding the species or genotypes that are the causal agents of both pre- and post-emergence damping off. Based on RFLP analysis with HhaI, HinfI and MboI of the PCR amplified ITS region DNA from soil and diseased plant samples, the majority of 130 Pythium isolates could be grouped into three genotypes, designated LVP A, LVP B and LVP C. These groups comprised 43, 41 and 7% of all isolates, respectively. Deoxyribonucleic acid sequence analysis of the ITS region indicated that LVP A was a strain of Pythium aphanidermatum, with greater than 99% similarity to the corresponding P. aphanidermatum sequences from the publicly accessible databases. The DNA sequences from LVP B and LVP C were most closely related to P. ultimum and P. dissotocum, respectively. Lower frequencies of other distinct isolates with unique RFLP patterns were also obtained with high levels of similarity (>97%) to P. heterothallicum, P. periplocum and genotypes of P. ultimum other than LVP B. Inoculation trials of 1- and 4-week-old beet seedlings indicated that compared with isolates of the LVP B genotype, a higher frequency of LVP A isolates caused disease. Isolates with the LVP A, LVP B and LVP C genotypes were highly sensitive to the fungicide Ridomil MZ, which suppressed radial growth on V8 agar between approximately four and thirty fold at 5 μg/mL metalaxyl and 40 μg/mL mancozeb, a concentration far lower than the recommended field application rate.

In vitro propagation of Corymbia torelliana x C. citriodora (Myrtaceae) via cytokinin-free node culture

Hybrids between Corymbia torelliana (F.Muell.) K.D.Hill & L.A.S.Johnson and C. citriodora subsp. variegata (F.Muell.) A.R.Bean & M.W.McDonald are used extensively to establish forestry plantations in subtropical Australia. Methods were developed for in vitro seed germination, shoot multiplication and plantlet formation that could be used to establish in vitro and ex vitro clone banks of juvenile Corymbia hybrids. Effects of sodium hypochlorite concentration and exposure time on seed contamination and germination, and effects of cytokinin and auxin concentrations on shoot multiplication and subsequent rooting, were assessed. A two-step surface sterilisation procedure, involving 70% ethanol followed by 1% sodium hypochlorite, provided almost no contamination and at least 88% germination. A novel method of cytokinin-free node culture proved most effective for in vitro propagation. Lateral bud break of primary shoots was difficult to induce by using cytokinin, but primary shoots rooted prolifically, elongated rapidly and produced multiple nodes in the absence of exogenous cytokinin. Further multiplication was obtained either by elongating lateral shoots of nodal explants in cytokinin-free medium or by inducing organogenic callus and axillary shoot proliferation with 2.2 µm benzyladenine. Plantlets were produced using an in vitro soil-less method that provided extensive rooting in sterile propagation mixture. These methods provide a means for simultaneous laboratory storage and field-testing of clones before selection and multiplication of desired genotypes.

Relationship between the Physicochemical Properties of Nonchitinolytic Listeria and Salmonella and Their Attachment to Shrimp Carapace

Listeria and Salmonella are important foodborne pathogens normally associated with the shrimp production chain. This study investigated the potential of Salmonella Typhimurium, Salmonella Senftenberg, and Listeria monocytogenes (Scott A and V7) to attach to and colonize shrimp carapace. Attachment and colonization of Listeria and Salmonella were demonstrated. Shrimp abdominal carapaces showed higher levels of bacterial attachment (P < 0.05) than did head carapaces. Listeria consistently exhibited greater attachment (P < 0.05) than did Salmonella on all surfaces. Chitinase activity of all strains was tested and found not to occur at the three temperatures (10, 25. and 37 degrees C) tested. The surface physicochemical properties of bacterial cells and shrimp carapace were Studied to determine their role in attachment and colonization. Salmonella had significantly (P < 0.05) more positive (-3.9 and -6.0 mV) cell surface charge than Listeria (-18 and -22.8 mV) had. Both bacterial species were found to be hydrophilic (<35%) when measured by the bacterial adherence to hydrocarbon method and by contact angle (theta) measurements (Listeria, 21.3 and 24.8 degrees, and Salmonella, 14.5 and 18.9 degrees). The percentage of cells retained by Pheryl-Sepharose was lower for Salmonella (12.8 to 14.8%) than it was for Listeria (26.5 to 31.4%). The shrimp carapace was found to be hydrophobic (theta = 74.5 degrees), and a significant (P < 0.05) difference in surface roughness between carapace types was noted. There was a linear correlation between bacterial cell Surface charge (r(2) = 0.95) and hydrophobicity (r(2) = 0.85) and initial attachment (P < 0.05) of Listeria and Salmonella to carapaces. However, the same properties Could not be related to subsequent colonization.

Salinity tolerance of twelve hybrid Bermudagrass (Cynodon Dactylon (L.) Pers. x C. Transvaalensis Burtt Davy) genotypes

Salinity is an increasingly important issue in both rural and urban areas throughout much of Australia. The use of recycled/reclaimed water and other sources of poorer quality water to irrigate turf is also increasing. Hybrid Bermudagrass (Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt Davey), together with the parent species C. dactylon, are amongst the most widely used warm-season turf grass groups. Twelve hybrid Bermudagrass genotypes and one accession each of Bermudagrass (C. dactylon), African Bermudagrass (C. transvaalensis) and seashore paspalum (Paspalum vaginatum Sw.) were grown in a glasshouse experiment with six different salinity treatments applied hydroponically through the irrigation water (ECW = <0.1, 6, 12, 18, 24 or 30 dSm-1) in a flood-and-drain system. Each pot was clipped progressively at 2-weekly intervals over the 12-week experimental period to determine dry matter production; leaf firing was rated visually on 3 occasions during the last 6 weeks of salinity treatment. At the end of the experiment, dry weights of roots and crowns below clipping height were also determined. Clipping yields declined sharply after about the first 6 weeks of salinity treatment, but then remained stable at substantially lower levels of dry matter production from weeks 8 to 12. Growth data over this final 4-week experimental period is therefore a more accurate guide to the relative salinity tolerance of the 15 entries than data from the preceding 8 weeks. Based on these data, the 12 hybrid Bermudagrass genotypes showed moderate salinity tolerance, with FloraDwarfM, 'Champion Dwarf', NovotekM and 'TifEagle' ranking as the most salt tolerant and 'Patriot', 'Santa Ana', 'Tifgreen' and TifSport M the least tolerant within the hybrid group. Nevertheless, Santa Ana, for example, maintained relatively strong root growth as salinity increased, and so may show better salt tolerance in practice than predicted from the growth data alone. The 12 hybrid Bermudagrasses and the single African Bermudagrass genotype were all ranked above FloraTeXM Bermudagrass in terms of salt tolerance. However, seashore paspalum, which is widely acknowledged as a halophytic species showing high salt tolerance, ranked well above all 14 Cynodon genotypes in terms of salinity tolerance.

A free-enzyme catalyst for the bioremediation of environmental atrazine contamination.

Herbicide contamination from agriculture is a major issue worldwide, and has been identified as a threat to freshwater and marine environments in the Great Barrier Reef World Heritage Area in Australia. The triazine herbicides are of particular concern because of potential adverse effects, both on photosynthetic organisms and upon vertebrate development. To date a number of bioremediation strategies have been proposed for triazine herbicides, but are unlikely to be implemented due to their reliance upon the release of genetically modified organisms. We propose an alternative strategy using a free-enzyme bioremediant, which is unconstrained by the issues surrounding the use of live organisms. Here we report an initial field trial with an enzyme-based product, demonstrating that the technology is technically capable of remediating water bodies contaminated with the most common triazine herbicide, atrazine.

Factors contributing to wear tolerance of Bermudagrass (Cynodon dactylon (L.) Pers., C. dactylon x C. transvaalensis Burtt-Davey) on a sand-based profile under simulated sports field conditions

Wear resistance and recovery of 8 Bermudagrass (Cynodon dactylon (L.) Pers.) and hybrid Bermudagrass (C. Dactylon x C. transvaalensis Burtt-Davey) cultivars grown on a sandbased soil profile near Brisbane, Australia, were assessed in 4 wear trials conducted over a two year period. Wear was applied on a 7-day or a 14-day schedule by a modified Brinkman Traffic Simulator for 6-14 weeks at a time, either during winter-early spring or during summer-early autumn. The more frequent wear under the 7-day treatment was more damaging to the turf than the 14-day wear treatment, particularly during winter when its capacity for recovery from wear was severely restricted. There were substantial differences in wear tolerance among the 8 cultivars investigated, and the wear tolerance rankings of some cultivars changed between years. Wear tolerance was associated with high shoot density, a dense stolon mat strongly rooted to the ground surface, high cell wall strength as indicated by high total cell wall content, and high levels of lignin and neutral detergent fiber. Wear tolerance was also affected by turf age, planting sod quality, and wet weather. Resistance to wear and recovery from wear are both important components of wear tolerance, but the relative importance of their contributions to overall wear tolerance varies seasonally with turf growth rate.

Morphological and developmental comparisons of seven greens quality hybrid bermudagrass (Cynodon dactylon (L.)Pers.x C transvaalensis Burtt-Davy

Fine-textured hybrid bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy] cultivars have been widely used for golf putting greens and lawn bowls greens in warm-climate areas for more than 40 years. During the past decade, the choice of cultivar for professional turfgrass managers has been expanded by a range of secondgeneration hybrid bermudagrasses, which differ from the first-generation cultivars ‘Tifgreen’ and ‘Tifdwarf ’ in their management requirements. In this paper, we present comparative morphological and developmental data for seven cultivars (Champion Dwarf, FloraDwarf, MS-Supreme, Novotek, Tifdwarf, TifEagle, Tifgreen) grown in spaced plant and sward experiments at Cleveland, Australia (27º32’S lat, 153º15’E long, 25 masl). The four ‘ultradwarf ’ cultivars (Champion Dwarf, MS-Supreme, FloraDwarf, TifEagle) showed slower vertical extension and produced fewer inflorescences than Tifdwarf, Tifgreen, and Novotek. However, in terms of the length of stolon internodes and their overall rate of lateral spread, Champion Dwarf, FloraDwarf, and TifEagle were comparable to Tifdwarf; MS-Supreme (with longer internodes) spread faster laterally, though slower than Tifgreen (which had the longest stolon internodes). In unmown swards, the four ultradwarfs produced shorter leaves than Tifgreen, Tifdwarf, and Novotek, but only Champion Dwarf produced significantly narrower leaves than Tifgreen, Tifdwarf, and Novotek, with TifEagle leaves also significantly narrower than those of Tifgreen and Novotek. Minimum threshold temperatures for growth were approximately 9° to 10°C (air temperature) and 15° to 16°C at 10 cm soil depth.

Relationships between Indole-3-butyric Acid, Photoinhibition and Adventitious rooting of Corymbia torelliana, C. citriodora and F1 Hybrid Cuttings

Rooted cutting propagation is widely used for maximising tree yield, quality and uniformity in conjunction with clonal selection. Some eucalypt species are deployed as rooted cuttings but many are considered to difficult to root. This study examined IBA effects on photoinhibition, root formation, mortality and root and shoot development in cuttings of Corymbia torelliana, C. citriodora and their hybrids. IBA had little or no effect on photoinhibition but it had strong, dose-dependent effects on root formation and mortality. IBA frequently increases primary root number of rooted cutting but it did not increase total root weight, length, surface area or volume, possibly because the highest doe (8g IBA/kg IBA/kg powder) caused leaf abscission and sometimes reduced leaf area (by 55-79%)or shoot dry weight (by 40-58%). An intermediate dose (3g IBA/kg powder) most consistnely improved root formation with little or no effect on mortality or shoot development. Across the F1 hybrid families this treatment increased the number of rooted cuttings by 72-121% and more than ddoubled the number of primary roots per rooted cutting (from 1.1-1.7 roots to 3.5-4.1 roots). This simple treatment will facilitate commercial multiplication of superior individuals or selected families of C. torelliana x C. citriodora through a vegetative propagation system.

Towards better management of Australia’s shark fishery: genetic analyses reveal unexpected ratios of cryptic blacktip species Carcharhinus tilstoni and C. limbatus

The common blacktip shark (Carcharhinus limbatus) and the Australian blacktip shark (C. tilstoni) are morphologically similar species that co-occur in subtropical and tropical Australia. In striking contrast to what has been previously reported, we demonstrate that the common blacktip shark is not rare in northern Australia but occurs in approximately equal frequencies with the Australian blacktip shark. Management of shark resources in northern Australia needs to take account of this new information. Species identification was performed using nucleotide sequences of the control, NADH dehydrogenase subunit 4 (ND4) and cytochrome oxidase I (COI) regions in the mitochondrial genome. The proportion of overall genetic variation (FST) between the two species was small (0.042, P < 0.01) based on allele frequencies at five microsatellite loci. We confirm that a third blacktip species (C. amblyrhynchoides, graceful shark) is closely related to C. tilstoni and C. limbatus and can be distinguished from them on the basis of mtDNA sequences from two gene regions. The Australian blacktip shark (C. tilstoni) was not encountered among 20 samples from central Indonesia that were later confirmed to be common blacktip and graceful sharks. Fisheries regulators urgently need new information on life history, population structure and morphological characters for species identification of blacktip shark species in Australia.

Soil C stocks in grains and sugar farming systems

Quantify soil C stocks in grains and sugarcane cropping systems of Queensland, including impacts of management practices.

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.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (c) Wood quality and structural properties.

This study provides information about wood quality, structural properties, processing characterists and product suitability of wood harvested from fast-grown hardwood plantations. Wood quality attributes tested included density, extractive content, unit shrinkage, heartwood proportion and sapwood width. Structural properties tested included small clear and full section strength and stiffness, hardness, joint group, visual grade assessment and natural vibration-based grade assessment. The variation between the inner, intermediate and outer heartwood zones and the variation between provenances was also tested. Overall, the wood qualtiy attributes measured for 19 year-old E. cloeziana and 15 year-old E. pellita plantation material fall between those expected from the wood of mature, native forest trees and those found in younger plantation material of the same species.