Commercial-scale Trials Research Articles

A Simple and Cost-Effective Technique to Monitor the Sublimation Flow During Primary Drying of Freeze-Drying Using Shelf Inlet/Outlet Temperature Difference or Chamber to Condenser Pressure Drop

As lyophilization continues to be a critical step in the manufacturing of sensitive biopharmaceuticals, challenges often arise during the scale up to commercial scale or the transfer from one manufacturing site to another. While data from the small-scale development of the lyophilization cycle is abundant it is typically much more difficult to extract important information from commercial scale cycles, due to the lack of process analytical technologies available on the commercial line. There is often a reluctance to include wireless temperature or pressure probes during GMP operations due to the additional contamination risk, and retrofitting equipment such as the TDLAS can be prohibitively expensive. Further, as products become more advanced, the cost of consuming the product or even the availability of material may limit the opportunities to run commercial scale trials. This paper presents two novel methods to garner critical cycle information to allow for the evaluation of cycle performance without the need for expensive analytical equipment, costly revalidation and line downtime. Critically, this can be achieved using commonly available temperature and capacitance probes on existing commercial scale equipment. The first method is a calorimetric method, based on quantifying the differences in heat transfer liquid temperature between the shelf inlet and shelf outlet. This change in temperature results from the on-going sublimation, an endo-thermic reaction occurring during lyophilization. The second method uses the differential pressure between the chamber and condenser resulting from the vapor flow from vial to condenser during primary drying. As stated by the authors both methods align well and provide valuable cycle characterization data.

Phage cocktail administration to reduce Salmonella load in broilers

Salmonella is a serious foodborne pathogen that can cause gastrointestinal disease through the consumption of contaminated foods; including poultry meat. Salmonella is commonly present in the intestinal tract of poultry and farm environments, posing a potential risk of contamination during the processing of poultry meat. This study was a continuation in evaluating the effects of our previously developed phage cocktail targeting Salmonella at large-scale trials in commercial broiler farms, in which this cocktail considerably lowered Salmonella colonization in the gut of broilers. The phage cocktail given to broilers showed resistance to temperatures of up to 65 °C (> 60% survivability), pH ranging from 2 to 12 (> 96% survivability), 0.5 to 15% (w/v) NaCl (> 98% survivability), chlorine up to 0.5% (v/v) (53% survivability), and chlorine neutralizer (100% survivability). In the animal challenge study, phage treatments, designed as “prevention” and “exclusion” programs, could control Salmonella on day 20 and 32 of the experiment, respectively; as indicated by the absence of Salmonella detection in cloacal swabs from broilers (0% prevalence). In the commercial-scale trial I, Salmonella was not detected in the phage-treated group from cloacal swabs, boot cover swabs, and bedding material samples after 16 days (0% prevalence) of phage administration. In the commercial-scale trial II, phage treatment extended the Salmonella control period in broilers during a 40-day growout period. In summary, a phage cocktail demonstrated high efficiency in controlling various serovars of Salmonella historically linked to contamination on these broiler farms. Phage cocktail application offers an effective, alternative to enhance food safety within the poultry value chain, protecting consumers and as well as the economic sustainability of the poultry sector.

Preliminary study to evaluate ethanedinitrile (C2 N2 ) for quarantine treatment of four wood destroying pests.

Methyl bromide is an ozone depleting substance and is still being used for quarantine treatment of wood products and logs. Ethanedinitrile (C2 N2 ) is a new potential alternative fumigant and has been investigated as a timber fumigant because it has shown better penetration through timber and responds fast to insects and nematodes. This article reports on laboratory and commercial-scale trials with C2 N2 for important wood destroying pests namely Tomicus piniperda (Pine bark beetle) adults, Hyphantria cunea (Fall webworm) lavae, Reticulitermes speratus (Japanese Termite) adults and Cryphalus fulvus (Scolytidae) (Yellow minute bark beetle) which naturally infests pine logs. Tomicus pi:niperda adults were more tolerance than H. cunea lavae and R. speratus adults with lethal concentration × time affecting 99% mortality (LCt99 ) values of 27.84, 7.49 and 3.30 g h m-3 , respectively. Ethanedinitrile shows exceptionally high toxicity to adult R. speratus which was almost 26 times more toxic than methyl bromide. The complete control of larvae and adults stages of C. fulvus was achieved at concentration × time (Ct) products from 89.6g h m-3 in a 6-8L fumigation chamber. Temperature-depending trials on C. fulvus were conducted with C2 N2 doses of 30 at 21 ± 6 and 40 g m-3 at 9 ± 3 and 2 ± 2°C for 24 h. The Ct products of 182.2, 227.8 and 268.6g h m-3 were obtained and C. fulvus was completely controlled at all tested temperatures. Ethanedinitrile could offer quarantine treatment for wood products and logs for the control of wood destroying insect pests and termites.

Meta-Analysis of Commercial-Scale Trials as a Means to Improve Decision-Making Processes in the Poultry Industry: A Phytogenic Feed Additive Case Study

Background and Objective: In the current study, we sought to determine the value of a meta-analysis to improve decision-making processes related to nutrition in the poultry industry. To this end, nine commercial size experiments were conducted to test the effect of a phytogenic feed additive and three approaches were applied to the data. Materials and Methods: In all experiments, 1-day-old male Cobb 500 chicks were used and fed corn-soybean meal diets. Two dietary treatments were tested: T1, control diet and T2, control diet + feed additive at a 0.05% inclusion rate. The experimental units were broiler houses (7 experiments), floor pens (1 experiment) and cages (1 experiment). The response variables were final body weight, feed intake, feed conversion ratio, mortality and production efficiency. Analyses of variance of data from each and all the experiments were performed using SAS under completely randomized non-blocked or blocked designs, respectively. The meta-analyses were performed in R programming language. Results: No statistically significant effects were found in the evaluated variables in any of the independent experiments (p>0.12), nor following the application of a block design (p>0.08). The meta-analyses showed no statistically significant global effects in terms of final body weight (p>0.19), feed intake (p>0.23), mortality (p>0.09), or European Production Efficiency Factor (p>0.08); however, a positive global effect was found with respect to feed conversion ratio (p<0.046). Conclusion: This meta-analysis demonstrated that the phytogenic feed additive improved the efficiency of birds to convert feed to body weight (35 g less feed per 1 kg of body weight obtained). Thus, the use of meta-analyses in commercial-scale poultry trials can increase statistical power and as a result, help to detect statistical differences if they exist.

Citrus Production Under Screen as a Strategy to Protect Grapefruit Trees From Huanglongbing Disease.

Citrus production under enclosed structures can exclude the Asian citrus psyllid (ACP, Diaphorina citri) and eliminate the negative effects of citrus greening or huanglongbing (HLB) disease caused by Candidatus Liberibacter asiaticus to the grapefruit (Citrus paradisi) fresh fruit industry. Physically impeding the insect vector from accessing trees is a logical method to have disease-free groves. Our objectives were to assess the ability of enclosed screenhouses to exclude the ACP, stop HLB inoculation and dissemination, and improve fruit yield of in-ground and container-grown 6-year-old “Ray Ruby” grapefruit at super-high planting densities relative to open-air trees. We built a large structure to allow commercial-scale trials and tested two production systems (screenhouse and open-air), two planting systems (in-ground and potted), and two rootstocks (“Sour Orange” [Citrus × aurantium] and “US-897” [Citrus reticulata × Poncirus trifoliate]). The experimental design was a randomized complete block design split-split-plot with four replications. Four passively ventilated 1,080-m2 completely enclosed screenhouses were constructed using a 50-mesh monofilament high-density polyethylene screen. The main support for each enclosed, covered structure consisted of pressure-treated, wooden utility poles. Trees were planted in Sept/2013 on a density of 1,957 trees/ha. Irrigation was performed on-demand using two 7.6-LPH drip emitters per tree, and fertigation was applied three times/week using 15N-2.6P-22.4K water-soluble fertilizer at 180 kg N/ha. Psyllids were monitored using sticky cards and detected inside the screenhouses post-Hurricane Irma, which damaged the screen structures in Sept/2017, leaving openings until repairs were completed in Apr/2018. Screen aging and a tropical storm in April/2019 caused another major screen opening fixed in Oct/2019. Despite the weather-related damages to the screens, only trees cultivated in open-air tested positive for Candidatus Liberibacter asiaticus after 6 years. There was fast disease progression for all outside treatments, with 100% infection. Covered, in-ground trees exhibited the highest trunk diameter and canopy volume (P < 0.0001). Trees grown inside screenhouses exhibited higher fruit yield than outside trees, with the highest yield observed for in-ground trees on “US-897” (51,081 kg/ha) (P < 0.0001). Several open-air treatments particularly in containers did not produce any fruit. On the other hand, potted grapefruit trees cultivated inside the enclosures had the highest soluble solids content (P < 0.001). The screenhouses provided disease exclusion, increased fruit yield, and fruit quality, representing an alternative for growers interested in producing high-quality fruit for the fresh market. Production cost and economic viability still need to be evaluated for large-scale implementation.

Feasibility and efficacy of using gaseous chlorine dioxide generated by sodium chlorite-acid reaction for decontamination of foodborne pathogens on produce

The objective of this study was to evaluate the feasibility and efficacy of using chlorine dioxide (ClO2) gas generated by dry media (sodium chlorite and ferric chloride) and sodium chlorite-hydrogen chloride dosing methods for decontamination of foodborne pathogens on produce. Tomatoes, blueberries, and baby-cut carrots inoculated with Shiga toxin-producing Escherichia coli, Salmonella, and Listeria monocytogenes were treated with ClO2 gas in a pilot-scale decontamination process. The effects of cumulative ClO2 exposure, i.e., ClO2 concentration (ppm) × treatment time (h) (ppm-h), on the reductions of inoculated pathogens were determined. Results showed that the increase of cumulative ClO2 exposure between 300 and 1900 ppm-h increased the log reductions of pathogens on produce, whereas no significant increase in log reductions was observed after 1900 ppm-h. The cumulative ClO2 exposures of 300, 1300, and 1600 ppm-h caused >4.0-log CFU/g reductions of the pathogens on baby-cut carrots, tomatoes, and blueberries, respectively. The treatment was most effective against the pathogens on baby-cut carrots, likely due to the moisture on the surface of the peeled carrots. This study showed that the two ClO2 generation methods are suitable and effective for decontamination of produce. The correlation between the cumulative ppm-h and pathogen reduction was independent of the quantity of products and other factors that may affect the consumption rate of ClO2. Therefore, the treatment parameters obtained from this study can be used for decontamination applications of similar scale or as references for evaluating using ClO2 gas for decontamination of tomatoes, blueberries, and baby-cut carrots in commercial-scale trials.

Fogging loads of California fresh citrus for control of Asian citrus psyllid, Diaphorina citri :

Contact insecticides are commonly applied as fogs to disinfest and disinfect spaces. Recently, these fogs have been adapted to treat commodity within the spaces, and much has been learned regarding the efficacy of this process. When considering fresh citrus in California, fogs are applied to control both insects and microbes. One insect pest, the Asian citrus psyllid (ACP), Diaphorina citri, is a quarantine pest in California and limiting its geographic distribution is a major goal of the California citrus industry. While a variety of phytosanitary measures can be used to control adult ACP once fruit is at a packing house, ultimately, a treatment must be developed to disinfest field-run fruit prior to its exiting the grove. High-pressure fogging with 1,100-L of an aqueous mixture containing 0.2% Evergreen® (6% pyrethrins & 60% piperonyl butoxide) and 0.5% (v/v) BreakThru® (polysiloxane surfactant) was explored in laboratory-, pilot-, and commercial-scale trials as an approach to disinfest a 48-bin trailer load of fresh citrus. Laboratory-scale studies were conducted to quantify, and subsequently model, insecticidal coverage as a function of temperature, surface area, droplet size, and fog volume. Results are discussed in the context of experimental variability across confirmatory trials and continued efforts to optimize the technical and economic feasibility of fogging as a postharvest control strategy.

Discrimination of Juice Press Fractions for Sparkling Base Wines by a UV-Vis Spectral Phenolic Fingerprint and Chemometrics

The feasibility of an ultraviolet-visible (UV-Vis) spectral phenolic fingerprint (SPF), combined with principal component analysis (PCA), is evaluated as a rapid, simple, and reliable technique for the discrimination of grape juice press fractions destined for the production of sparkling white wines. Juice press fractions of Vitis vinifera L. Chardonnay and Pinot noir grapes comprising free-run (i.e., juice released during the loading of press), cuvée (i.e., first press fraction), and taille (i.e., subsequent press fraction), were analyzed by SPF combined with multivariate data analysis. Two trials were carried out, a laboratory and a commercial scale trial. In both trials, cuvée and taille of Chardonnay and Pinot noir grapes were clearly separated in their corresponding PCA plots based on their SPF. The proposed method enables a rapid and objective discrimination of juice press fractions, which can be obtained using relatively inexpensive UV-Vis spectrophotometric equipment. Insights arising from this research suggest a future possibility of objective, real-time discrimination of juice quality that could liberate the winemaker from tasting juice at the press.

HERBICIDE SCREENING FOR THE CONTROL OF ROLANDRA FRUTICOSA

Several herbicides were screened to determine their efficacy against an invasive weed, Rolandra fruticose. Tank-mix of 44.5 ml glyphosate isopropylamine 48.6 per cent w/v plus 100 ml triclopyr butotyl-ethyl-ester (BEE) 67.0 per cent wlv in 10 L water and tank-mix of 75 ml glufosinate ammonium 15.0 per cent wlv plus 2.22 g saflufenacil 70 per cent wlw in 10 L water achieved 100 per cent kill at the fifth and first week after treatment respectively. The weed did not regenerate in both treatments at the eleventh week, the duration of the trial. In the second trial, the dosage was reduced by 50 per cent and 75 per cent for both treatments. At the reduced dosage, they were equally effective against this weed. A tank-mix of glyphosate isopropylamine and triclopyr BEE at the three rates evaluated in the second trial were repeated in a large commercial scale trial done by the estate. It was confirmed that the lowest dosage of 12 ml glyphosate isopropylamine 48.6 per cent wlv plus 25 ml triclopyr BEE 67. 0 per cent wlv in 10 L water was effective in controlling the weed. However, a follow-up spraying was required to eliminate the missed patches. The combination of 75 ml glufosinate ammonium 15.0 per cent wlv plus 2.22 g saflufenacil 70 per cent wlw in 10 L water also provided good control of R. fruticosa and could be recommended as an alternative. Keywords: Rolandra fruticosa, weed management, invasive weed.

An overview of cleaner fish use in Ireland.

Sea lice infestations represent one of the most significant challenges facing the salmon farming industry, giving rise to lost production, additional costs of treatment and potential negative interactions with wild stocks. At present, cleaner fish, which actively remove lice from salmon, are an effective, biological, long-term option which has been adopted by many countries. In Ireland, several key studies were conducted in the 1990s on the use of wild-caught wrasse (corkwing, goldsinny and rock cook) as cleaner fish in experimental and commercial scale trials. More recently, the National University of Ireland Galway (NUIG), at their marine research facility in Carna (CRS), has undertaken applied research on ballan wrasse and lumpsucker. Currently, CRS is providing lumpsucker juveniles and research and development for the Irish salmon industry with support from BIM (Ireland's Seafood Development Agency) and Marine Harvest Ireland. There is a large amount of research currently being carried out in this area in all countries that are utilizing cleaner fish technology. The current focus in Ireland is the development of a native lumpsucker broodstock to facilitate its sustainable production. The aim of this article was to provide an overview of the research, challenges and use of cleaner fish in Ireland.

Sustainable Weed Management in the Commercial Tea Industry: The Case of Hapugastenne Estate, Maskeliya

Tea sector of Sri Lanka earns US$ 1.6 billion net foreign exchange annually while caring over one million direct and indirect employments and 2.5 million dependents. Controlling of problematic weeds is important to maintain steady and quality crop levels in commercial tea. Real effectiveness of plant killer chemicals (weedicides) in commercial tea is questionable against the emergence of various unintended and unforeseen detrimental side effects on the eco-systems, human health and tea bushes. The purpose of this study is to demonstrate the economic, environmental and social benefits of Herbicide Free Integrated Weed Management (HFIWM) over chemical weeding in the commercial tea industry. A commercial scale trial on HFIWM was conducted in Hapuhastenne Estate, where natural regeneration of vegetation was allowed to form a ground cover, ceasing the usage of weedicides completely, whilst selective periodic removal of harmful weeds grown in the experimental tea area. These results were compared against the control plots of non-HFIWM tea area in the garden. Analysis showed an improvement in overall performance of tea bushes in the long run with HFIWM, enhancing the product quality and soil environment. Moreover HFIWM approach exhibits many direct and indirect benefits over chemical weeding in commercial tea in the lines of crop productivity, cost of inputs, public health, environment and the socio-economic factors. HFIWM approach was therefore, found economically, socially and environmentally more desirable. The study reveals HFIWM approach could be a sound solution to mitigate many of the constraints faced by the present day commercial tea industry in Sri Lanka.

Commercial Scale Cucumber Fermentations Brined with Calcium Chloride Instead of Sodium Chloride.

Development of low salt cucumber fermentation processes present opportunities to reduce the amount of sodium chloride (NaCl) that reaches fresh water streams from industrial activities. The objective of this research was to translate cucumber fermentation brined with calcium chloride (CaCl2 ) instead of NaCl to commercial scale production. Although CaCl2 brined cucumber fermentations were stable in laboratory experiments, commercial scale trials using 6440 L open-top tanks rapidly underwent secondary cucumber fermentation. It was understood that a limited air purging routine, use of a starter culture and addition of preservatives to the cover brine aids in achieving the desired complete cucumber fermentation. The modified process was used for subsequent commercial trials using 12490 and 28400 L open-top tanks packed with variable size cucumbers and from multiple lots, and cover brines containing CaCl2 and potassium sorbate to equilibrated concentrations of 100 and 6 mM, respectively. Lactobacillus plantarum LA0045 was inoculated to 10(6) CFU/mL, and air purging was applied for two 2-3 h periods per day for the first 10 d of fermentation and one 2-3 h period per day between days 11 and 14. All fermentations were completed, as evidenced by the full conversion of sugars to lactic acid, decrease in pH to 3.0, and presented microbiological stability for a minimum of 21 d. This CaCl2 process may be used to produce fermented cucumbers intended to be stored short term in a manner that reduces pollution and waste removal costs.

Comparison of the Effects of Neonicotinoids and Pyrethroids AgainstOebalus pugnax(Hemiptera: Pentatomidae) in Rice

The rice stink bug, Oebalus pugnax (F.) (Hemiptera: Pentatomidae), is an economically important late-season pest of rice in the southern United States. Stink bug feeding results in yield reduction and discounted purchase price due to broken or discolored (“pecky”) rice grains. The primary tactic for O. pugnax management is the application of insecticides once adults reach an action threshold. Recent surveys show that pyrethroids are preferred by southern U.S. rice farmers over all other insecticides to reduce O. pugnax densities. However, preliminary tests in 2009 suggested resistance to pyrethroids may be developing in an O. pugnax population in Texas, where applications are more frequent than in other rice-growing areas. This study compared the effects of pyrethroids and neonicotinoids on O. pugnax behavior and mortality in the laboratory and in a number of field experiments conducted between 2011 and 2014. Results from these experiments showed that control of O. pugnax given by the neonicotinoid, dinotefuran, was similar to that given by pyrethroids in the laboratory and field. Results from small-plot field studies were influenced by movement of adult rice stink bugs from surrounding untreated plots, and the data from commercial-scale trials and from sampling of nymphs in small plots may provide more useful information on the efficacies of insecticides. Two experiments provided limited evidence for longer residual activity of dinotefuran compared to the pyrethroid λ-cyhalothrin, and a laboratory study showed that both insecticides reduced feeding activity of rice stink bugs. Tests also confirmed the increased tolerance of a Texas population of rice stink bugs to λ-cyhalothrin, suggesting the need for insecticides with different modes of action in the O. pugnax management program.

Manipulation of farmed Atlantic salmon swimming behaviour through the adjustment of lighting and feeding regimes as a tool for salmon lice control

Abstract This paper describes a study in which environmental manipulation of salmon swimming depth was tested in an attempt to reduce farm infection of Atlantic salmon, Salmo salar by the salmon louse, Lepeophtheirus salmonis. The effects of submerged artificial lighting (positioned at 10 m depth) in combination with submerged feeding (delivered at 5 m depth) were tested with respect to salmon swimming depth and sea lice infection, following the hypothesis that L. salmonis infection in a commercial salmon population is reduced when exposed to deep lighting and feeding. This is based on two assumptions, firstly that planktonic L. salmonis larvae principally remain in surface waters (top 4 m) and secondly, that deep lighting and feeding attract salmon to deeper water depths. Results from commercial scale trials confirmed that salmon swimming behaviour is altered under submerged feeding conditions with fish attracted to the feeding corridor during the feeding process. When the fish reached satiation or feeding ceased, they returned to the surface waters during the day. Submerged lighting attracted the fish to the illuminated water depths during the night. During the day, natural light overruled these effects to some extent. The number of L. salmonis on fish exposed to deep submerged lighting was significantly lower than the number of lice found on salmon in cages with surface lighting during the summer months. Submerged feeding showed no advantage over surface feeding with respect to the number of L. salmonis found in these trials. The results of the study suggest that swimming depth manipulation can be used at a commercial scale to reduce salmon lice burdens on Atlantic salmon stocks.

Sustainable management for rangelands in a variable climate: evidence and insights from northern Australia

Inter-annual rainfall variability is a major challenge to sustainable and productive grazing management on rangelands. In Australia, rainfall variability is particularly pronounced and failure to manage appropriately leads to major economic loss and environmental degradation. Recommended strategies to manage sustainably include stocking at long-term carrying capacity (LTCC) or varying stock numbers with forage availability. These strategies are conceptually simple but difficult to implement, given the scale and spatial heterogeneity of grazing properties and the uncertainty of the climate. This paper presents learnings and insights from northern Australia gained from research and modelling on managing for rainfall variability. A method to objectively estimate LTCC in large, heterogeneous paddocks is discussed, and guidelines and tools to tactically adjust stocking rates are presented. The possible use of seasonal climate forecasts (SCF) in management is also considered. Results from a 13-year grazing trial in Queensland show that constant stocking at LTCC was far more profitable and largely maintained land condition compared with heavy stocking (HSR). Variable stocking (VAR) with or without the use of SCF was marginally more profitable, but income variability was greater and land condition poorer than constant stocking at LTCC. Two commercial scale trials in the Northern Territory with breeder cows highlighted the practical difficulties of variable stocking and provided evidence that heavier pasture utilisation rates depress reproductive performance. Simulation modelling across a range of regions in northern Australia also showed a decline in resource condition and profitability under heavy stocking rates. Modelling further suggested that the relative value of variable v. constant stocking depends on stocking rate and land condition. Importantly, variable stocking may possibly allow slightly higher stocking rates without pasture degradation. Enterprise-level simulations run for breeder herds nevertheless show that poor economic performance can occur under constant stocking and even under variable stocking in some circumstances. Modelling and research results both suggest that a form of constrained flexible stocking should be applied to manage for climate variability. Active adaptive management and research will be required as future climate changes make managing for rainfall variability increasingly challenging.

Do cues matter? Highly inductive settlement cues don't ensure high post-settlement survival in sea urchin aquaculture.

Increasing settlement and post-settlement survival during the critical transition from planktonic larvae to benthic juveniles will increase efficiency for sea urchin aquaculture. This study investigated the effects of temperature and settlement cues on the settlement and post-settlement survival of the sea urchin Tripneustes gratilla during this phase. The current commercial methodology, which utilises natural biofilm settlement plates, was tested and resulted in low settlement (<2%) and poor post-settlement survival (<1% of settled urchins). In laboratory trials, settlement was high and unaffected by temperatures between 24 and 30°C, but significantly decreased at 33°C. Development of spines, however, was significantly affected by temperatures over 29°C. Mirroring this result, post-settlement survival was optimal between 24–28°C. In laboratory assays, the macroalgae Sargassum linearifolium and Corallina officinalis, and seawater conditioned with these algae, induced significantly higher settlement (>90%) than a natural biofilm (∼25%). The addition of macroalgae-conditioned seawater to natural biofilm significantly increased settlement rates (>85%). Mixed consortia and single strains of bacteria isolated from macroalgae, biofilms and adult conspecifics all induced significant settlement, but at significantly lower rates than macroalgae. No evidence was found that higher rates of settlement to bacteria on macroalgae were generated by a cofactor from the macroalgae. Age of bacterial cultures, culturing bacteria on solid and liquid media and concentration of nutrients in cultures had little effect on settlement rates. Finally, macroalgae-conditioned seawater combined with natural biofilm settlement plates induced significantly higher settlement than to the biofilm plates alone in a commercial scale trial. However, high post-settlement mortality resulted in equivalent survival between treatments after 25 days. This study highlights that settlement studies should extend to post-settlement survival, which remains poor for T. gratilla and is a significant obstacle to increasing efficiency for aquaculture.

Environmentally friendly treatment alternatives to Bordeaux mixture for controlling bacterial apical necrosis (BAN) of mango

Bacterial apical necrosis (BAN), caused by the bacterium Pseudomonas syringae pv. syringae (Pss), is currently the most limiting disease affecting the mango crop in the Mediterranean area. The copper‐based compound Bordeaux mixture (BM) is considered to be the conventional treatment against BAN, but it does not act as a bactericide. Alternative experimental treatments to BM that are compatible with organic farming were tested for their ability to control BAN disease. Field trials were conducted over six seasons in different mango orchards with natural infestation of Pss. The experimental treatments included applications of Silicon gel (a commercial formulation of aqueous potassium silicate), dicalcium phosphate, Kaolinite, and Ulmasud B® (bentonite, powder); BM was applied as the conventional treatment. During the first two seasons (small‐scale trial, 2002–2004), all these experimental compounds were applied in order to select those treatments providing the greatest reduction of BAN symptoms. In the next three seasons (2005–2008), a semi‐commercial scale trial was carried out with the best‐performing treatments, resulting in the selection of Silicon gel. Finally, Silicon gel was tested in a commercial scale trial during the last season (2008–2009). Trees treated with Silicon gel showed significantly fewer necrotic buds and leaves, reaching disease levels very similar to those using the conventional treatment with BM. However, minor differences in P. syringae‐like population levels were observed, as has been described in previous studies. The possible mode of action of the Silicon gel is discussed. Currently, the Silicon gel compound is undergoing the registration process for its commercial use in mango management in Spain.

Factors influencing the efficiency of constructed wetlands used for the treatment of intensive trout farm effluent

In this paper the factors influencing treatment performance of subsurface flow constructed wetlands (SSF wetlands) treating aquaculture effluents were identified and quantified. The financial impact of advanced aquaculture effluent treatment with SSF wetlands was calculated. It is the first long-term, commercial-scale trial of SSF wetland treatment for effluents from intensive trout farming, a highly diluted effluent at very high flow rates (mean total phosphorous concentration 0.34 mg L −1 at 14.3 L s −1). The 12-month survey provided the opportunity to generate calculation fundamentals for the commercial application of SSF wetlands for aquaculture. Treatment efficiencies of up to 75–86% for total ammonia nitrogen (TAN), biological oxygen demand (BOD 5) and total suspended solids (TSS) were achieved. The daily area retention rate per square meter wetland area was between 2.1 and 4.5 g for TAN and between 30 and 98 g for TSS. The performance of the six wetland cells comprising three replicated hydraulic loading groups (14.5, 6.9, 3.3 m 3 m −2 day −1) was monitored, offering the possibility to identify factors influencing treatment efficiency through multifactor analysis. These factors turned out to be nutrient inflow concentration, hydraulic loading rate and accumulation of TSS within the wetland bed, the only time-dependent factor. Factors such as vegetation period and fish harvesting were shown to be of significant but negligible importance. Inflow nutrient concentration is determined by production intensity, husbandry conditions, feed quality and any pre-treatment of effluent. Hydraulic load is determined by the space and budget available for SSF construction. TSS accumulation in the wetland is influenced by pre-treatment of the solid fraction prior to the wetland and determines the wetland service lifetime. From these factors the expenses of commercial wetland application can be estimated, leading to a cost increase around €0.20 kg −1 fish produced (less than 10% of production costs) and therefore confirm the commercial feasibility of SSF wetland treatment.

Monticello: A mid-season variety with good tuber appearance and chipping potential from mid-to long-term storage

Monticello (NY102), a new medium-maturing, roundwhite chipping variety was released in 2003 by the University of Maine and Cornell University. It is primarily intended for use in the chipping industry, especially from mid-to long-term storage. Its ability to chip from relatively long-term storage, low storage weight loss, and relatively long tuber dormancy should be particularly valuable. Tubers have shown a good ability to recondition and regain good chip color after periods of stress in storage. Monticello’s specific gravity typically averages only a few points lower than Atlantic, a variety that is widely used for out-of-field chipping in the eastern U.S. Chip color of Monticello has been very good from short-, mid-, and long-term storage. It has been grown successfully in commercial-scale tests in Maine since 1999 with combined seed and chipping production of more than 37 and 60 ha during 2001 and 2002, respectively. Research and commercial-scale trials in Maine have generally produced favorable yield and quality results relative to other storage chippers like Snowden. The tubers are bright and attractive with relatively few external defects. Tuber size tends to be fairly small and is ideal for chipping. Sensory panel tests have also shown that Monticello is good for boiling and baking. Although ideally suited for chipping, the fresh market may serve as a secondary market for this variety because of its typically good external appearance and cooking quality scores. Monticello has moderate to good common scab resistance and is resistant to golden nematode. It is moderately susceptible to blackspot bruise, powdery scab, and typical foliar diseases of potato. Although tubers can develop hollow heart and internal heat necrosis, Monticello is typically much less susceptible than Atlantic.

Residual moisture reduction in coarse coal centrifuges using air purging. Part 3. Commercial scale trials

CSIRO/Novatech Consulting have been developing air purging as a new way of reducing the moisture content of coarse coal products from vibrating basket centrifuges. The process involves injecting a turbulent stream of high velocity air, via an air knife manifold, through the coal bed as it traverses the centrifuge basket. This paper describes the results obtained when the process was trialled in a commercial scale centrifuge, following successful previous bench and pilot scale work reported previously. Five manifolds of different shapes and sizes were tested. The best results were achieved with units of square cross-section, located close to the outlet edge of the basket. Depending on air speed, product moisture was reduced by between 0.7 and 0.9 wt% at a confidence level exceeding 95%. The best results approached closely the 1.0 wt% moisture reduction target which had been adopted as the project objective. Air purging had no significant effect on the content or size distribution of the solids in the centrate. Increasing air speed led to larger moisture reductions. Higher air speeds were needed compared with previous pilot scale work probably due to the thicker beds encountered in the full scale centrifuge. Despite the higher air speed, the actual air usage (cfm/t of coal) was much more efficient at full scale, being less than half that at pilot scale.