Baseline responses of Alphitobius diaperinus (Coleoptera: Tenebrionidae) to spinosad, and susceptibility of broiler populations in eastern and southern Australia

Spinosad was proposed as a potential chemical for control of lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), in Australian broiler houses after the detection of strong cyfluthrin resistance in many beetle populations. In 2004-2006, spinosad susceptibility of 13 beetle populations from eastern and southern Australian broiler houses and a cyfluthrin/fenitrothion-resistant reference population was determined using topical application, and was compared with the susceptibility of an insecticide-susceptible reference population. Comparisons of dose-response curves and baseline data showed that all populations, including the insecticide-susceptible population, were roughly equivalent in their response to spinosad, indicating no preexisting spinosad resistance. Two field populations, including the resistant reference population, which had confirmed cyfluthrin/fenitrothion- resistance, showed no cross-resistance to spinosad. There was no significant correlation between beetle weight and LC99.9. A discriminating concentration of 3% spinosad was set to separate resistant and susceptible individuals. Considering the levels of spinosad resistance that have been recorded in other insect pests, the sustained future usefulness of spinosad as a broiler house treatment will rely on effective integrated beetle management programs combined with carefully planned chemical use strategies.

Evaluation of three storage systems used for chilling and holding swordfish

Swordfish are kept chilled, not frozen, for up to 15 days before being unloaded at Australian ports. Swordfish landed alive, and to a lesser extent prerigor, have better quality when unloaded. Warmer fishing waters did not lead to poorer quality at unloading. There was a serious loss of quality during long fishing trips. Sex had no influence on swordfish quality. Three methods of chilling were evaluated: refrigerated seawater (RSW) chilling for up to 2 days followed by storage under ice, refrigerated brine (seawater with extra salt added) for up to 2 days followed by storage in a freshwater ice slurry, and ice slurry (freshwater ice mixed with seawater) for up to 2 days followed by storage under ice only. Two fishing trips were monitored for each method. The freshness indicator K value was used to determine which method produced the best quality swordfish when unloaded at the factory. Storage method played a larger role in quality loss than capture conditions. Refrigerated brine produced the best quality swordfish when the machinery functioned properly closely followed by RSW. Ice slurry chilling of large fish such as swordfish exhibited initial delays in the reduction of core temperature which led to lower quality. This method could be improved with the addition of mechanical circulation. Mechanical problems, which resulted in minor increases of temperature during brine storage, led to a much larger loss of quality than would be expected.

Value-adding Australian sardines: Factors affecting rates of deterioration in sardine (Sardinops sagax) quality during post-harvest handling

Deficiencies in sardine post-harvest handling methods were seen as major impediments to development of a value-adding sector supplying Australian bait and human consumption markets. Factors affecting sardine deterioration rates in the immediate post-harvest period were investigated and recommendations made for alternative handling procedures to optimise sardine quality. Net to factory sampling showed that post-mortem autolysis was probably caused by digestive enzyme activity contributing to the observed temporal increase in sardine Quality Index. Belly burst was not an issue. Sardine quality could be maintained by reducing tank loading, and rapid temperature reduction using dedicated, on-board value-adding tanks. Fish should be iced between the jetty and the processing factory, and transport bins chilled using an efficient cooling medium such as flow ice.

Using a supply chain approach to guide R&D

Consumers today are presented with an increasing array of products. The growing competition for consumer expenditure requires a whole of supply chain approach to maintain market share for existing cultivars and to successfully commercialise new cultivars. The supply chain needs to deliver value and satisfaction to the end customer and profitability to their members. Critical to getting the product right is developing inherent robustness into the cultivar, and developing processes and systems through the whole supply chain that maintain product quality and add value. This paper describes the approach we have used in working with supply chains in Australia and Indonesia to identify priority areas for improvement. Our experience demonstrates the need for a champion in the supply chain with significant influence and a desire to improve. The paper also describes our approach towards improving a specific supply chain to achieve successful commercialisation of a new cultivar. The cultivar was primarily selected for good production characteristics and attractive visual appeal. The performance of the fruit is being monitored from farm to retail shelf to identify points where quality is lost and practices can be improved. A targeted R&D program is investigating ways of improving production efficiency (nutrition, flowering and canopy management), maturity standards to optimise flavour, harvesting and packing practices to reduce skin damage, and ripening and handling practices to optimise shelf life. This integrated approach is based on similar approaches used to improve the performance of existing mango and avocado cultivars.

Skin damage to two new mango cultivars during irradiation and cold storage.

Mangoes can express several skin disorders following important postharvest treatments. Responses are often cultivar specific. This paper reports the responses of two new Australian mango cultivars to some of these treatments. 'Honey Gold' mango develops "under skin browning" early during cold storage. This is thought to be partly caused by a discolouration of the latex vessels which then spreads to the surrounding cells. The symptoms appear to be worse in fruit from hotter production areas and that have been cooled to temperatures below 18C soon after harvest. Current commercial recommendations are to cool fruit to 18C, which limits postharvest handling options. Recent trials have confirmed that delayed or slowed cooling after harvest can reduce under skin browning. The defect may also be associated with physical injury to the skin during harvesting and packing. Irradiation is potentially an important disinfestation treatment for fruit fly in Australian mangoes. The 'B74' mango cultivar develops significant skin damage following irradiation, mainly due to discolouration of the cells surrounding the lenticels. Recent results confirmed that fruit harvested directly from the tree into trays without exposure to water or postharvest chemicals are not damaged by irradiation, while commercially harvested and packed fruit are damaged. Several major harvest and postharvest steps appear to increase lenticel sensitivity to irradiation. Further work is required to develop commercially acceptable protocols to facilitate 'Honey Gold' and 'B74' mango distribution and marketing.

Optimise efficacy of broiler house treatments for the management of lesser mealworm

The Australian chicken meat industry requires effective agents for the management of lesser mealworm in broiler houses. The only two appropriate insecticides currently registered are cyfluthrin and spinosad, with gamma cyhalothrin being developed for registration. The industry requires the efficacy of cyfluthrin to be investigated, with progress and adoption of the latter two chemicals. Optimising the efficacy of each chemical and studying them singly and in rotation will, in addition to improving their efficacy, reduce overall insecticide use and improve their cost effectiveness.

Improving fruit quality and profitability of 'Honey Gold' mango

Honey Gold mango is a new Australian variety owned by a Queensland company, and in high demand because of very good flavour and appearance. It develops under skin browning (USB) when grown in hot areas. It appears after packing and the fruit need to be re-sorted at the markets to remove affected fruit. Production and postharvest treatments will be developed to reduce USB and increase profitability. Other production and harvest factors causing quality loss will be also be identified through a commercial downgrade analysis program in the packhouse. Grower training will reduce downgrades and improve the percentage of fruit in premium grade.

Development of an avocado rapid library tray system for Hass

The aim of the project is to develop a rapid ripening protocol/test which can be used as a reliable library tray system for Hass Avocados. Fruit will be taken from the end of the packing line to reflect both commercial handling quality and intrinsic fruit quality.

Reducing flesh bruising and skin spotting in Hass avocado

Up to 80% of avocados on the retail shelf have defects in the flesh which reduces consumer satisfaction. Flesh bruising is the single most important contributor. Avocados also develop skin spotting during harvesting and packing which can reduce domestic and international customer confidence. This project will identify where bruising occurs, develop decision aid tools to help industry reduce flesh bruising in ripe fruit, and understand the commercial impacts of skin spotting. The project will include a PhD student with stipend coming from an international scholarship and in kind support from the University of Queensland.

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.

Reducing the incidence of under-skin browning in 'Honey Gold' mango (Mangifera indica L.) fruit

'Honey Gold' mango is a relatively new cultivar in Australia, with an appealing skin colour and a sweet fibre-free flesh. However, fruit can develop 'under-skin browning' (USB), which appears several days after packing as a distinct 'bruise'-like discolouration under the epidermis and can affect large areas of the fruit surface. We investigated the anatomy of USB and the impact of post-harvest fruit handling conditions on the disorder. Starch accumulated around the resin canals and discoloured cells in the affected area, with no visible change to the cuticle or epidermis. Delays of 1 d at ambient temperature (27 degrees - 35 degrees C) before packing, and 2 d at 18 degrees - 20 degrees C (after packing), before placing fruit at 12 degrees - 14 degrees C and road transportation, reduced the incidence of USB by 83% compared to placing fruit at 12 degrees - 14 degrees C within 13 h of picking. The incidence of USB was 88 100% higher in fruit that were cooled to 12 degrees - 14 degrees C within 13 h of picking, then commercially road-freighted for 4 d at 12 degrees - 14 degrees C, than in fruit held under similar temperature conditions, but not road-freighted. Wrapping each fruit in bubble-wrap to minimise direct contact with other fruit, with the plastic insert, or with the cardboard tray, reduced the incidence of USB by 84% after road-freight compared to not using bubble-wrap. These results suggest that USB is a unique disorder of mango skin associated with a rapid post-harvest reduction in temperature, from high ambient temperatures to 12 degrees - 14 degrees C, and with physical damage during road-freight.

Field Assessments of Control Agents for Lesser Mealworm (Coleoptera: Tenebrionidae) Using Litter Sampling

Spinosad, diatomaceous earth, and cyfluthrin were assessed on two broiler farms at Gleneagle and Gatton in southeastern Queensland, Australia in 2004-2005 and 2007-2009, respectively to determine their effectiveness in controlling lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae). Insecticide treatments were applied mostly to earth or 'hard' cement floors of broiler houses before the placement of new bedding. Efficacy of each agent was assessed by regular sampling of litter and counting of immature stages and adult beetles, and comparing insect counts in treatments to counts in untreated houses. Generally, the lowest numbers of lesser mealworm were recorded in the house with hard floors, these numbers equalling the most effective spinosad applications. The most effective treatment was a strategic application of spinosad under feed supply lines on a hard floor. In compacted earth floor houses, mean numbers of lesser mealworms for two under-feed-line spinosad treatments (i.e., 2-m-wide application at 0.18 g of active insecticide (g [AI]) in 100-ml water/m(2), and 1-m-wide application at 0.11 g ([AI] in 33-ml water/m(2)), and an entire floor spinosad treatment (0.07 g [AI] in 86-ml water/m2) were significantly lower (i.e., better control) than those numbers for cyfluthrin, and no treatment (controls). The 1-m-wide under-feed-line treatment was the most cost-effective dose, providing similar control to the other two most effective spinosad treatments, but using less than half the active component per broiler house. No efficacy was demonstrated when spinosad was applied to the surface of bedding in relatively large volumes of water. All applications of diatomaceous earth, applied with and without spinosad, and cyfluthrin at the label rate of 0.02 g (AI)/100-ml water/m(2) showed no effect, with insect counts not significantly different to untreated controls. Overall, the results of this field assessment indicate that cyfluthrin (the Australian industry standard) and diatomaceous earth were ineffective on these two farms and that spinosad can be a viable alternative for broiler house use.

Interaction between production characteristics and postharvest performance and practices for fresh fruit

Significant interactions have been demonstrated between production factors and postharvest quality of fresh fruit. Accordingly, there is an attendant need for adaptive postharvest actions to modulate preharvest effects. The most significant preharvest effects appear to be mediated through mineral nutrition influences on the physical characteristics of fruit. Examples of specific influencers include fertilisers, water availability, rootstock, and crop load effects on fruit quality attributes such as skin colour, susceptibility to diseases and physiological disorders, and fruit nutritional composition. Also, rainfall before and during harvest can markedly affect fruit susceptibility to skin blemishes, physical damage, and diseases. Knowledge of preharvest-postharvest interactions can help determine the basis for variability in postharvest performance and thereby allow refinement of postharvest practices to minimise quality loss after harvest. This knowledge can be utilised in predictive management systems. Such systems can benefit from characterisation of fruit nutritional status, particularly minerals, several months before and/or at harvest to allow informed decisions on postharvest handling and marketing options. Other examples of proactive management practices include adjusting harvesting and packing systems to account for rainfall effects before and/or during harvest. Improved understanding of preharvest-postharvest interactions is contributing to the delivery of consistently higher quality of fruit to consumers. This paper focuses on the state of knowledge for sub-tropical and tropical fruits, in particular avocado and mango.

Evaluation of the use of prochloraz in the control of postharvest diseases of papaya in Australia

Prochloraz as Sportak at 450 g a.i./L is registered for the control of postharvest diseases in papaya in Australia. A project in far north Queensland in 2011, examined the use patterns of postharvest treatments, evaluated treatment dips and sprays for prochloraz concentrations and evaluated the efficacy of prochloraz at 0, 20, 40, 55 and 70 ml/100 L, fludioxonil as Scholar at 260 ml/100 L and azoxystrobin as Amistar at 50 ml/100 L. Results showed that packing shed use of Sportak varied with recycled and stored solutions showing a depletion of the active ingredient. Measured prochloraz in solution was highly pH dependent with nominal solution values only being measured when the pH was less than 3.0. In the fungicide efficacy trial Sportak at the label rate of 55 ml/100 L provided more effective disease control than fludioxonil and azoxystrobin. The trial also suggested that fruit from older trees showed a high degree of disease incidence relative to fruit from young trees.

Interaction between production characteristics and postharvest performance and practices for fresh fruit

Significant interactions have been demonstrated between production factors and postharvest quality of fresh fruit. Accordingly, there is an attendant need for adaptive postharvest actions to modulate preharvest effects. The most significant preharvest effects appear to be mediated through mineral nutrition influences on the physical characteristics of fruit. Examples of specific influencers include fertilisers, water availability, rootstock, and crop load effects on fruit quality attributes such as skin colour, susceptibility to diseases and physiological disorders, and fruit nutritional composition. Also, rainfall before and during harvest can markedly affect fruit susceptibility to skin blemishes, physical damage, and diseases. Knowledge of preharvest-postharvest interactions can help determine the basis for variability in postharvest performance and thereby allow refinement of postharvest practices to minimise quality loss after harvest. This knowledge can be utilised in predictive management systems. Such systems can benefit from characterisation of fruit nutritional status, particularly minerals, several months before and/or at harvest to allow informed decisions on postharvest handling and marketing options. Other examples of proactive management practices include adjusting harvesting and packing systems to account for rainfall effects before and/or during harvest. Improved understanding of preharvest-postharvest interactions is contributing to the delivery of consistently higher quality of fruit to consumers. This paper focuses on the state of knowledge for sub-tropical and tropical fruits, in particular avocado and mango.