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Mareeba, Australia

Sallam N.,BSES Ltd | Burgess D.J.W.,BSES Ltd | Lowe G.E.,DEEDI | Peck D.R.,AQIS
33rd Annual Conference of the Australian Society of Sugar Cane Technologists 2011, ASSCT 2011 | Year: 2011

A STUDY ON insect pests of sugarcane on the Tableland (FNQ) revealed the existence of a number of scarab species inflicting variable degrees of damage to the crop. The greyback canegrub (Dermolepida albohirtum) was the dominant species followed by Anoplognathus porosus and A. boisduvali. Larvae of Lepidiota sororia, L. laevis and L. sparsa were found in different locations, however, these species are mainly associated with pasture and are unlikely to be of any economic importance in sugarcane. Other pests included the Sugarcane Weevil Borer (Rhabdoscelus obscurus) and several armyworm species belonging to the genera Leucania, Athetis and Nodaria, and these yielded a wide range of dipterous and hymenopterous parasitoids. In addition, the webworm Oncopera sp., which is mainly a pest of pasture, was encountered feeding on sugarcane setts near Tolga. Insecticides registered for the management of the greyback canegrub proved effective against species of Anoplognathus. This study revealed the existence of a different suite of pest species on the Tableland compared to coastal areas, possibly due to the Tableland's inland location and higher elevation and the fact that it is relatively new to cane plantations. It is possible that, due to the recent expansion of sugarcane plantations on the Tableland at the expense of pasture land, species associated with pasture are occasionally found in sugarcane fields. Pest monitoring is therefore recommended to continue on the Tableland in case any of these pests expand their host range to include sugarcane.

Pattison A.,DEEDI | Kukulies T.,DEEDI | Forsyth L.,DEEDI | Geense P.,Wageningen University
Acta Horticulturae | Year: 2014

There is a need to develop indicators that relate the dynamics of soil organic carbon (SOC) with changes in land management of horticultural production systems. Soil nematode communities have been shown to be sensitive to land management changes, but often do not include plant-parasites in the calculation of soil nematode community indices. The concept of nematode functional guilds was used to estimate the proportion of carbon entering the soil ecosystem through different channels, such as through decomposition of organic material, the detrital channel, through the roots of plants, the root channel or recycled through the activity of predators, a predation channel. Calculations of the indices were developed and validated using case studies in the north Queensland banana industry. Firstly, a survey of organic and conventional banana farms found a greater proportion of C entering the soil ecosystem through the detrital channel and a reduced proportion of C originating through the root channel at the organic sites relative to conventional sites. Secondly, a field experiment comparing compost amendments, found application of fresh compost significantly increased the proportion of C entering the soil ecosystem through the detrital channel and decreased proportion of C originating from the root channel. Thirdly, a field experiment comparing 'conventional' banana production to an 'alternative' system which incorporated organic matter, found the proportion of C entering the soil ecosystem through the root channel was significantly greater in the conventional systems relative to the alternative system. This research demonstrates that nematode indices can be used to assess horticultural systems, by indicating the origins of SOC.

Williams D.J.,DEEDI | Critchley C.,University of Queensland | Pun S.,DEEDI | Chaliha M.,DEEDI | O'hare T.J.,DEEDI
Journal of Agricultural and Food Chemistry | Year: 2010

The chemical nature of the hydrolysis products from the glucosinolate-myrosinase system depends on the presence or absence of supplementary proteins such as epithiospecifier proteins (ESPs). ESPs promote the formation of epithionitriles from terminal alkenyl glucosinolates and, as recent evidence suggests, simple nitriles at the expense of isothiocyanates. From a human health perspective isothiocyanates are the most important because they are major inducers of carcinogen-detoxifying enzymes. Fe2+ is an essential factor in ESP activity, although several recent studies have highlighted discrepancies in the understanding of the ESP-iron interaction. To investigate further the role iron species play in regulating ESP activity, four ESP-containing seedpowders were analyzed for ESP and myrosinase activities, endogenous iron content, and glucosinolate degradation products after the addition of iron species, specific chelators, and reducing agents. For the first time this paper shows the effect of these additions on the hydrolysis of individual glucosinolates that constitute the total pool. Aged seeds and 3-day seedlings were also tested to investigate the effects of seed storage and early plant development on iron levels and ESP activity. The four ESP-containing plant systems tested gave two distinctive responses, thus providing strong evidence that ESPs vary markedly in their Fe2+ requirement for activity. The results also indicated that reduction of ferric to ferrous iron drives variations in ESP activity during early plant development. The reverse oxidation reaction provided a convincing explanation for the loss of ESP activity during seed storage. Aged seeds produced seedlings with substantially lower ESP activity, and there was a concomitant loss in germination rate. It was concluded that manipulation of endogenous iron levels of ESP-containing plants could increase the conversion of glucosinolates to isothiocyanates and enhance potential health benefits. © 2010 American Chemical Society.

Kukulies T.,DEEDI | Pattison A.,DEEDI | Forsyth L.,DEEDI | Nelson P.,James Cook University
Acta Horticulturae | Year: 2014

The major banana production areas in Australia are particularly sensitive to environments due to their close proximity to areas of World Heritage rainforest and the Great Barrier Reef catchment. Management of soil quality, nutrients and pesticides are vital to maintaining the integrity of these sensitive areas. Studies on cropping systems have suggested that integrating organic matter into ground cover management would improve the quality of soil under banana cultivation. In this study, an alternative management practice for bananas, which addresses the management of organic matter and fertiliser application, was assessed and compared to the conventional practice currently employed in the banana industry. Several chemical, physical and biological soil parameters were measured including: pH, electrical conductivity, water stable aggregates, bulk density, water filled pore space, porosity, water content, fluorescein diacetate hydrolyis (FDA) and β-glucosidase activity. The alternative management practice did not have a significant impact of the production and growth of bananas but overall improved the quality of the soil. Although some differences were observed, the chemical and physical soil characteristics did not differ dramatically between the two management systems. The addition of organic matter resulted in the soil under alternative practice having higher FDA and β-glucosidase levels, indicating higher microbial activity. The integration of organic matter into the management of bananas resulted in positive benefits on soil properties under bananas, however, methods of maintaining organic matter in the soil need to be further researched.

Stirling G.R.,Biological Crop Protection Pty. Ltd. | Smith M.K.,DEEDI | Smith J.P.,DEEDI | Stirling A.M.,Biological Crop Protection Pty. Ltd. | Hamill S.D.,DEEDI
Australasian Plant Pathology | Year: 2012

A field experiment was established in which an amendment of poultry manure and sawdust (200 t/ha) was incorporated into some plots but not others and then a permanent pasture or a sequence of biomass-producing crops was grown with and without tillage, with all biomass being returned to the soil. After 4 years, soil C levels were highest in amended plots, particularly those that had been cropped using minimum tillage, and lowest in nonamended and fallowed plots, regardless of how they had been tilled. When ginger was planted, symphylans caused severe damage to all treatments, indicating that cropping, tillage and organic matter management practices commonly used to improve soil health are not necessarily effective for all crops or soils. During the rotational phase of the experiment, the development of suppressiveness to three key pathogens of ginger was monitored using bioassays. Results for root-knot nematode (Meloidogyne javanica) indicated that for the first 2 years, amended soil was more suppressive than non-amended soil from the same cropping and tillage treatment, whereas under pasture, the amendment only enhanced suppressiveness in the first year. Suppressiveness was generally associated with higher C levels and enhanced biological activity (as measured by the rate of fluorescein diacetate (FDA) hydrolysis and numbers of free-living nematodes). Reduced tillage also enhanced suppressiveness, as gall ratings and egg counts in the second and third years were usually significantly lower in cropped soils under minimum rather than conventional tillage. Additionally, soil that was not disturbed during the process of setting up bioassays was more suppressive than soil which had been gently mixed by hand. Results of bioassays with Fusarium oxysporum f. sp. zingiberi were too inconsistent to draw firm conclusions, but the severity of fusarium yellows was generally higher in fumigated fallow soil than in other treatments, with soil management practices having little impact on disease severity. With regard to Pythium myriotylum, biological factors capable of reducing rhizome rot were present, but were not effective enough to suppress the disease under environmental conditions that were ideal for disease development. © Australasian Plant Pathology Society Inc. 2011.

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