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1.
Environ Pollut ; 240: 412-421, 2018 Sep.
Article En | MEDLINE | ID: mdl-29753249

Ammonia emissions vary greatly at a local scale, and effects (eutrophication, acidification) occur primarily close to sources. Therefore it is important that spatially distributed emission estimates are located as accurately as possible. The main source of ammonia emissions is agriculture, and therefore agricultural survey statistics are the most important input data to an ammonia emission inventory alongside per activity estimates of emission potential. In the UK, agricultural statistics are collected at farm level, but are aggregated to parish level, NUTS-3 level or regular grid resolution for distribution to users. In this study, the Modifiable Areal Unit Problem (MAUP), associated with such amalgamation, is investigated in the context of assessing the spatial distribution of ammonia sources for emission inventories. England was used as a test area to study the effects of the MAUP. Agricultural survey data at farm level (point data) were obtained under license and amalgamated to different areal units or zones: regular 1-km, 5-km, 10-km grids and parish level, before they were imported into the emission model. The results of using the survey data at different levels of amalgamation were assessed to estimate the effects of the MAUP on the spatial inventory. The analysis showed that the size and shape of aggregation zones applied to the farm-level agricultural statistics strongly affect the location of the emissions estimated by the model. If the zones are too small, this may result in false emission "hot spots", i.e., artificially high emission values that are in reality not confined to the zone to which they are allocated. Conversely, if the zones are too large, detail may be lost and emissions smoothed out, which may give a false impression of the spatial patterns and magnitude of emissions in those zones. The results of the study indicate that the MAUP has a significant effect on the location and local magnitude of emissions in spatial inventories where amalgamated, zonal data are used.


Air Pollutants/analysis , Air Pollution/statistics & numerical data , Ammonia/analysis , Environmental Monitoring/methods , Agriculture , England , Models, Chemical , Uncertainty
2.
Sci Rep ; 7(1): 1890, 2017 05 15.
Article En | MEDLINE | ID: mdl-28507306

Fertilization of nitrogen (N)-limited ecosystems by anthropogenic atmospheric nitrogen deposition (Ndep) may promote CO2 removal from the atmosphere, thereby buffering human effects on global radiative forcing. We used the biogeochemical ecosystem model N14CP, which considers interactions among C (carbon), N and P (phosphorus), driven by a new reconstruction of historical Ndep, to assess the responses of soil organic carbon (SOC) stocks in British semi-natural landscapes to anthropogenic change. We calculate that increased net primary production due to Ndep has enhanced detrital inputs of C to soils, causing an average increase of 1.2 kgCm-2 (c. 10%) in soil SOC over the period 1750-2010. The simulation results are consistent with observed changes in topsoil SOC concentration in the late 20th Century, derived from sample-resample measurements at nearly 2000 field sites. More than half (57%) of the additional topsoil SOC is predicted to have a short turnover time (c. 20 years), and will therefore be sensitive to future changes in Ndep. The results are the first to validate model predictions of Ndep effects against observations of SOC at a regional field scale. They demonstrate the importance of long-term macronutrient interactions and the transitory nature of soil responses in the terrestrial C cycle.

3.
J Environ Manage ; 165: 106-116, 2016 Jan 01.
Article En | MEDLINE | ID: mdl-26413804

Trees are very effective at capturing both gaseous and particulate pollutants from the atmosphere. But while studies have often focussed on PM and NOx in the urban environment, little research has been carried out on the tree effect of capturing gaseous emissions of ammonia in the rural landscape. To examine the removal or scavenging of ammonia by trees a long-range atmospheric model (FRAME) was used to compare two strategies that could be used in emission reduction policies anywhere in the world where nitrogen pollution from agriculture is a problem. One strategy was to reduce the emission source strength of livestock management systems by implementing two 'tree-capture' systems scenarios - tree belts downwind of housing and managing livestock under trees. This emission reduction can be described as an 'on-farm' emission reduction policy, as ammonia is 'stopped' from dispersion outside the farm boundaries. The second strategy was to apply an afforestation policy targeting areas of high ammonia emission through two planting scenarios of increasing afforestation by 25% and 50%. Both strategies use trees with the aim of intercepting NH3 emissions to protect semi-natural areas. Scenarios for on-farm emission reductions showed national reductions in nitrogen deposition to semi-natural areas of 0.14% (0.2 kt N-NHx) to 2.2% (3.15 kt N-NHx). Scenarios mitigating emissions from cattle and pig housing gave the highest reductions. The afforestation strategy showed national reductions of 6% (8.4 kt N-NHx) to 11% (15.7 kt N-NHx) for 25% and 50% afforestation scenarios respectively. Increased capture by the planted trees also showed an added benefit of reducing long range effects including a decrease in wet deposition up to 3.7 kt N-NHx (4.6%) and a decrease in export from the UK up to 8.3 kt N-NHx (6.8%).


Ammonia/analysis , Animal Husbandry , Livestock , Models, Theoretical , Trees , Animals , Atmosphere , Cattle , Ecosystem , Environmental Pollution/prevention & control , Gases , Nitrogen/analysis , Swine
4.
Br J Pharmacol ; 172(2): 388-402, 2015 Jan.
Article En | MEDLINE | ID: mdl-24641506

UNLABELLED: Opioid and α2 -adrenoceptor agonists are potent analgesic drugs and their analgesic effects can synergize when co-administered. These supra-additive interactions are potentially beneficial clinically; by increasing efficacy and/or reducing the total drug required to produce sufficient pain relief, undesired side effects can be minimized. However, combination therapies of opioids and α2 -adrenoceptor agonists remain underutilized clinically, in spite of a large body of preclinical evidence describing their synergistic interaction. One possible obstacle to the translation of preclinical findings to clinical applications is a lack of understanding of the mechanisms underlying the synergistic interactions between these two drug classes. In this review, we provide a detailed overview of the interactions between different opioid and α2 -adrenoceptor agonist combinations in preclinical studies. These studies have identified the spinal cord as an important site of action of synergistic interactions, provided insights into which receptors mediate these interactions and explored downstream signalling events enabling synergy. It is now well documented that the activation of both µ and δ opioid receptors can produce synergy with α2 -adrenoceptor agonists and that α2 -adrenoceptor agonists can mediate synergy through either the α2A or the α2C adrenoceptor subtypes. Current hypotheses surrounding the cellular mechanisms mediating opioid-adrenoceptor synergy, including PKC signalling and receptor oligomerization, and the evidence supporting them are presented. Finally, the implications of these findings for clinical applications and drug discovery are discussed. LINKED ARTICLES: This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.


Receptors, Adrenergic, alpha-2/metabolism , Receptors, Opioid/metabolism , Adrenergic alpha-Agonists/pharmacokinetics , Adrenergic alpha-Agonists/pharmacology , Analgesia , Analgesics, Opioid/pharmacology , Animals , Drug Synergism , Humans
7.
Commun Agric Appl Biol Sci ; 77(3): 163-71, 2012.
Article En | MEDLINE | ID: mdl-23878970

Natural resistance against Venturia pirina and Botrytis cinerea was investigated within the Sardinian pears germplasm. The natural occurrence of V. pirina was monitored at the orchard level for 5 years, while resistance against B. cinerea was evaluated by a bioassay using methanolic extracts of the fruit rind or by artificially inoculation. Methanolic extracts of the leaves were employed for the Cladosporium bioassay on TLC plates. Among the accessions, 8 resulted sensitive to V. pirina, vegetation and fruit are severely affected every year. Seven showed an intermediate behaviour and the sole vegetation was affected slightly in two out of the 5 years. Two inhibition spots, in the methanolic extract of the leaves, were clearly evidenced in 55 accessions and a positive correlation was found between the presence of these antifungal compounds in the leaves and the resistance to V. pirina in the field. The artificial inoculation of fruit with B. cinerea evidenced a great variability in resistance, with about 12 accessions that could be considered having a good resistance. The fruit rind methanolic extracts evidenced several inhibition spots in most accessions, but no correlation could be found with fruit resistance to B. cinerea. In addition, the activity of the polygalacturonase inhibiting protein (PGIP), determined with an agarose diffusion bioassay, indicate a positive correlation between the PGIP activity evidenced in the core tissue and the infection degree by B. cinerea.


Ascomycota/physiology , Botrytis/physiology , Plant Diseases/microbiology , Pyrus/microbiology , Pyrus/physiology , Biological Assay , Italy , Polygalacturonase/antagonists & inhibitors
8.
Commun Agric Appl Biol Sci ; 77(3): 181-6, 2012.
Article En | MEDLINE | ID: mdl-23878972

The International trade has to ensure food security and preserve both human health and the diffusion of animal and plant diseases among different countries. While organic horticultural production and trade are regulated by global guidelines, no specific restrictions relay to conventional commodities and almost free import-export occurs among UE countries. Consequently, the safety characteristics of imported fresh crops have become an important issue. On the basis of these considerations, the aim of the present study is to monitor the epiphytic microflora (particularly yeasts and fungi) carried by fresh fruit, imported from Spain to Italy. Particular attention was given to pathogenic microrganisms and to natural antagonists. In addition, the resistance to a few postharvest fungicides was determined for the isolated strains and compared to the local ones. Apples, Citrus fruits, stone fruits, and persimmon fruit were sampled at arrival of the container from Spain at the wholesale market in Sassari (Italy), this to prevent fruit contamination by local strains of microrganisms. The isolation was performed by rinsing and shaking (30 min at 100 rpm) the fruit in a beaker with 500 mL of sterile water. After concentration (7.5 mL), 100 microl of the rinse water was plated on potato dextrose agar (PDA). Isolation of pure colonies was performed by multiple streaking on plates, until unicellular cultures were obtained. Fifty three microrganisms, mainly fungi and yeasts, have been isolated and assayed in vitro and in vivo. Pathogenic behavior of isolated fungi was tested on fruits artificially wounded and only 7 strains out of 18 isolates caused decay. The resistance to different concentrations of imazalil (IMZ), tiabendazolo and azoxystrobin were tested in vitro for the pathogenic isolates. All isolates were completely inhibited with 1000 ppm IMZ evidencing that no resistant strains were present on the imported fruit. Since the baseline resistance, found for all isolates, was similar to the indigenous strains, we may conclude from this risk analysis that the import of the studied fruits produced in the 4 geographical areas of Spain does not increase the local baseline resistance.


Commerce , Fruit/microbiology , Fungi/isolation & purification , Plant Diseases/prevention & control , Fungi/drug effects , Fungicides, Industrial/pharmacology , Italy , Plant Diseases/microbiology , Risk Factors , Spain
9.
Commun Agric Appl Biol Sci ; 77(3): 219-24, 2012.
Article En | MEDLINE | ID: mdl-23878976

The most important pathogen for table grapes is Botrytis cinerea which causes a rapid deterioration of fruit. Postharvest losses are controlled with SO2 fumigations carried out every 7 or 10 days, but the use of this gas is becoming more difficult to justify because of undesirable effects on the fruit and the increasing concern for human health. Acetic acid, classified as a GRAS compound, can be employed with no restriction as preservative and represents a possible substitute to sulphur dioxide. The aims of the present work were: (1) to evaluate if repeated treatments with AAC during storage preserve table grapes fruit quality; (2) to verify the effectiveness of 3 different concentrations and time intervals between each treatment and compare the effects with SO2 treatment; The amounts of AAC used in each fumigation, performed for 15 minutes, were 30, 50 and 75 microL/L, and treatments were carried out 5, 3 and 2 times respectively during storage, in order to have the same final concentration (150 microL/L). Table grapes were also fumigated with SO2. Fruit was stored for 8 weeks at 5 degrees C and 95% of RH, followed by 4 days of a simulated shelf-life (SSL) at 20 degrees C and 85% RH. At the end of experiment decay, weight loss and visual assessment were evaluated. After eight weeks of storage the incidence of grey mould, with respect to untreated fruit, was reduced in all treatments. The comparison among the different treatments did not show significant differences between the fumigations performed 3 and 2 times, with 24.9% and 27.2% of rots respectively. A better decay control was achieved with 5 fumigations carried out every 2 weeks, (18.1% of rots), while decay in fruit treated with SO2 was 26.2%. During the SSL period no particular differences were observed among all treatments. None of the treatments affected weight loss, as well as no differences were found in the score attributed for the external quality (rachis browning and berries appearance). The results showed that a good control of grey mould could be achieved on table grapes by repeated fumigations during storage. AAC could be a promising compound to be used as alternative to SO2 in keeping fruit quality.


Acetic Acid/pharmacology , Fruit/drug effects , Fungicides, Industrial/pharmacology , Vitis/physiology
10.
Commun Agric Appl Biol Sci ; 77(4): 503-7, 2012.
Article En | MEDLINE | ID: mdl-23885417

Ultrasonic technology is known for many years and is used for several purposes such as sonochemistry, extraction of natural compounds, degassing of solvent, inactivation of enzymes and microorganism. In postharvest ultrasound is applied in not destructive analysis of crop for the determination of the maturation stage. Until now, however, the potential of the sonication as a physical mean for not conventional postharvest treatment of fresh fruit has been little investigated. Here we report on the results obtained with apple fruit (Malus domestica Borkh. cv San Giovanni, from Sardinian germplasm) dipped in a solution of potassium sorbate with or without sonication. Treatment was carried out with an ultrasonic processor (1500 W, 20Khz) connected to a 25 mm phi probe immersed in 10 L of deionized water placed in a steel vessel. Fruit at different ripening stages, inoculated or not inoculated with Penicillium expansum, was sonicated before or after the inoculation. Following the treatment, fruit was left to dry, put into boxes and cold-stored. Results showed that ultrasound alone enhanced the natural resistance of ripe fruit when inoculated after sonication. No effect was observed when the ultrasound application was carried out after inoculation with P. expansum on un-ripe or ripe apples. Potassium sorbate showed to be ineffective in controlling the decay regardless of the ripening stage and the time of inoculation. On the contrary, a significant enhance in decay control was observed when the application of potassium sorbate was performed in the presence of ultrasound.


Food Storage , Malus/microbiology , Penicillium/drug effects , Plant Diseases/prevention & control , Sorbic Acid/pharmacology , Sound , Fruit/growth & development , Fruit/microbiology , Malus/growth & development , Penicillium/growth & development , Plant Diseases/microbiology , Sonication
11.
Commun Agric Appl Biol Sci ; 77(4): 509-14, 2012.
Article En | MEDLINE | ID: mdl-23885418

In the latest years, investigation on postharvest treatments has been increasingly addressed to preserve human health and environment safeguard. Several preservative compounds, physical treatments and biological control agents to restrain postharvest pathogens on horticultural products have been widely studied. Among them potassium sorbate (KS) has been generally recognized as safe for use in foods and personal care products. It acts as microbial growth inhibitor and fungistatic agent in foods, including vegetable and fruit products. The efficacy of KS, used alone or combined with heat treatments or biocontrol agents, has been demonstrated in Citrus and stone fruits. Here we report the results of 3 experiments aimed at controlling Penicillium expansum Link decay with the use of KS on a yellow ('Shiro') and a red ('Sanguigna di Bosa II', from the Sardinian germplasm) plum cultivar. An integrated approach, combining ultrasounds (US) as a physical mean and KS solutions at different concentrations, has been employed. In the first experiment, 360 fruits were wounded twice and divided into 6 sets (6 x 60), three of which were inoculated with an isolate of P. expansum (20 microl of a 10(5) cfu x mL(-1)). Then, 180 fruit (half inoculated) were treated by pipetting into each wound 20 microl of a KS solution containing 0, 1.5 or 3% (w/v), respectively. In exp. 2, all fruit (number) was wounded and inoculated, and after 24 h treated by immersion (1 min) into solutions containing 0, 1.5 or 3% (w/v) of SK, with or without the use of US. In exp. 3, wounded fruits were treated by immersion or sonication like in exp. 2, while inoculation took place after 24 h. Then, plums were kept at 25 degrees C and 75-80% RH and the infection degree was monitored after 3 and 6 days. In both cultivars, the 1.5% KS solution significantly reduced the natural infection, while the 3% KS solution resulted effective only on the red one. Moreover, the 1.5% solution was effective in controlling decay of artificially inoculated fruit, achieving a 56% reduction compared to control. Similar results were attained in exp. 2 and 3, where the combination of salt and sonication improved the efficacy, likely by increasing the salt diffusion into the wounds.


Penicillium/drug effects , Plant Diseases/prevention & control , Prunus/microbiology , Sorbic Acid/pharmacology , Sound , Fruit/growth & development , Fruit/microbiology , Penicillium/growth & development , Plant Diseases/microbiology , Prunus/genetics , Prunus/growth & development
12.
Commun Agric Appl Biol Sci ; 77(4): 515-25, 2012.
Article En | MEDLINE | ID: mdl-23885419

To gain knowledge on the influence of postharvest treatments with ultraviolet-C light upon the keeping quality of table grapes, a trail was performed employing commercially mature 'Corina', 'Dawn Seedless', 'Centennial Seedless' and 'Gran Perlon' grape cultivars (cvs). After grading, bunches were subjected to 0.0, 0.5, 1.5 or 3 kJm(-2) and then stored at 5 degrees C and 90% relative humidity (RH) for 6 weeks followed by a 2 day shelf-life at 25 degrees C and 70% RH. A weekly inspection was performed and a visual evaluation of the appearance, treatment damage, stems browning and berry shrivelling was performed. Weight loss, decay and shatter were quantified at the end of storage and shelf-life. Regardless the cv and UV-C dose, fruit appearance was acceptable until the end of storage and shelf-life. Among the cvs, the highest score was held by 'G. Perlon'. After the fourth week of storage, the berries of 'Centennial S.' turned light brown and darkened over time when treated with 3.0 kJm(-2). Stem browning was not induced by the light treatment, but resulted cv depended and was pronounced for 'Centennial S.' and 'Dawn S.'. Berry shrivelling was insignificant, while shatter was very high in 'Corina' and did not depend upon UV-C treatment. Regarding weight loss, differences could not be attributed to the light treatment and after storage it ranged from 3 up to 5%. Decay was significantly reduced by light treatment and the efficacy increased by raising the dose. Botrytis cinerea was the main cause of decay with 'Corina' being the most jeopardized, followed by 'Dawn S.' and 'Centennial S.', whereas 'G. Perlon' resulted the less affected. In conclusion, hormetic effects of postharvest light treatment on table grapes were observed in almost all cvs with 'G. Perlon' having the best performance.


Botrytis/radiation effects , Plant Diseases/prevention & control , Ultraviolet Rays , Vitis/microbiology , Botrytis/growth & development , Chromatography, High Pressure Liquid , Food Storage , Fruit/genetics , Fruit/metabolism , Fruit/microbiology , Plant Diseases/microbiology , Resveratrol , Stilbenes/metabolism , Vitis/genetics , Vitis/metabolism
13.
Commun Agric Appl Biol Sci ; 76(4): 721-5, 2011.
Article En | MEDLINE | ID: mdl-22702192

Penicillium expansum and Botrytis cinerea are among the pathogens most frequently affecting apples and grapes after harvest, respectively. We studied the behaviour of these moulds when subjected to different concentrations of methanol (MeOH) and dimethyl sulfoxide (DMSO) as a alternative method to fungicides in controlling postharvest decay of horticultural products. The experiments were performed with 5 cm Petri dishes containing PDA amended with 0, 5, 10, 20, 30, 40 or 50 microL/mL of the two tested chemicals. Freshly prepared conidia of B. cinerea and P. expansum were sown onto the media and then kept into an incubation chamber at 21 degrees C up to 3 and 6 days, respectively. Daily, the colony forming units (cfu), the colony diameter and the degree of sporification were monitored. Compared to the control, both chemicals affected the growth rate of the two pathogens. The P. expansum and B. cinerea cfu value was not significantly inhibited but the colony diameter and the sporification degree decreased when concentration was raised. B. cinerea cultured on DMSO showed a significant drop of sporification up to the tested concentration of 10 microL/mL, and a complete inhibition of cfu when the concentration was higher than 20 microL/mL.


Botrytis/drug effects , Dimethyl Sulfoxide/pharmacology , Fungicides, Industrial/pharmacology , Methanol/pharmacology , Penicillium/drug effects , Spores, Fungal/physiology , Botrytis/physiology , Dose-Response Relationship, Drug , Penicillium/physiology
14.
Commun Agric Appl Biol Sci ; 76(4): 737-42, 2011.
Article En | MEDLINE | ID: mdl-22702194

The restricted number of postharvest fungicides used in packing houses is leading to the selection of resistant strains of Penicillium digitatum (citrus green mould), one of the most common and serious pathogens during storage and marketing of lemons. Furthermore a growing concern for human health and a greater awareness for environmental conservation have multiplied the studies on new ecological technologies. Among the alternatives to synthetic postharvest fungicides, the use of acetic acid (classified as GRAS) together with a physical method such as curing, have led to encouraging results. In the present study is reported the combined use of curing, performed at reduced times compared to those reported to be effective, followed by acetic acid (AAC) treatments. Lemons of the variety "Limone di Massa" artificially inoculated with P. digitatum at a concentration of 10(4) spores/mL were cured for 0, 3, 6, 12 and 24 hours and then treated with three different concentrations of AAC (25, 50 and 75 microL/L) for 15 min. Fruit was then stored at 20 degrees C and 80% relative humidity (RH) for 9 days, when the number of decayed fruits was monitored. The same combined treatments were also carried out on naturally infected lemons, stored for 6 or 8 weeks at 5 degrees C and 90% RH. After 9 days of storage the lowest percentage of infected wounds, in artificially inoculated fruit, was 0% after 6 hours of curing followed by AAC fumigation performed at 50 microL/L, while lemons untreated or cured for three hours showed the worst results with 71.4 and 61.9% of rotted fruit respectively. In naturally infected lemons the best results were achieved with curing performed for 24 hours followed by AAC fumigation at 50 microL/L. In these cases the combined treatment reduced decay by the 91.0 and 66.5% after 6 or 8 weeks of storage respectively, if compared to untreated fruit. The weight loss was not affected by any of the treatments. These results show that a good control of green mould during storage could be achieved, on lemon fruit, by combining a reduced curing time of 24 hours to the effect of AAC. The best results were obtained after 6 week of storage even if a satisfactory control was observed after 8 weeks of storage.


Acetic Acid/pharmacology , Citrus/microbiology , Food Microbiology , Fruit/microbiology , Penicillium/drug effects , Time Factors
15.
Commun Agric Appl Biol Sci ; 76(4): 743-50, 2011.
Article En | MEDLINE | ID: mdl-22702195

The employment of biocontrol agents to restrain postharvest pathogens is an encouraging approach, although, efficacy and consistency are still below those of synthetic pesticides. Up to date, the 'integrated control strategy' seems to be the most promising way to overcome this gap. Here, we report the feasibility to control postharvest decay caused by Penicillium expansum in apples by a 2 min, single or sequential, immersion in water with an antagonistic yeast (Candida oleophila, isolate '13L'), 2% NaHCO3 (SBC) or 1% CaCl2. The treatments were carried out, on appels cv 'Miali' either un-wounded, wounded or wound-pathogen inoculated and then stored at 2 degrees C for 30 d followed by a 6 d simulated marketing period at 20 degrees C or alternatively stored only for 7 d at 20 degrees C. As a general role, the best results were attained when CaCl2 was applied with the yeast or when preceded by the SBC treatment. When the wounding and inoculation took place 24 h before the treatment, the latter application sequence of the two salts was three times more effective compared to the treatment with the sole antagonist, and one time when performed 24 h after the treatment. Interestingly, apples immersed in the sole 2% SBC solution had the highest percentage of decay during storage and when inoculated before moving to the simulated marketing period at 20 degrees C.


Calcium Chloride/pharmacology , Candida/physiology , Penicillium/drug effects , Penicillium/physiology , Plant Diseases/prevention & control , Sodium Bicarbonate/pharmacology , Food Preservation , Malus/microbiology , Time Factors
16.
Commun Agric Appl Biol Sci ; 75(4): 555-62, 2010.
Article En | MEDLINE | ID: mdl-21534462

The activity of 2-deoxy-D-gLucose (2-DG) alone or in combination with a biocontrol yeast (Candida saitoana, strain 8C) was evaluated in vitro and in vivo against citrus green mould (Penicillium digitatum Sacc.). The in vitro assays were performed on amended potato dextrose agar (PDA) containing 0, 1.5, 3.0, 6.0, 15.0, 30.0 or 60.0 mM of 2-DG. P. digitatum conidia were sown on the amended media and growth inhibition occurred starting from 6.0 mM. A nearly total inhibition of the growth and spore germination occurred with 60.0 mM of 2-DG. The antagonist was not affected by any of the 2-DG concentrations employed and the amended plates resulted well colonized within 2 d post-treatment. In vivo assays were carried out with 'Hamlin' oranges, inoculated with P. digitatum 24 h before treating with: the antagonist; the above reported concentrations of 2-DG, or by combining the two treatments. Seven days post-treatment the inhibition activity exerted by 3.0, 6.0, 15.0, 30.0 and 60.0 mM of 2-DG combined with the yeast was 15, 37, 42, 63 and 84%, respectively. While that exerted by the antagonist was 22% and that by the different concentrations of 2-DG were 7, 11, 27, 42 and 57%, respectively. Compared to single treatments, the co-application significantly and in a synergic mode improved the control of decay. Alterations to the hyphae were observed by SEM when the pathogen was cultured on amended media and into the wounds of inoculated oranges.


Antibiosis , Candida/physiology , Citrus/microbiology , Deoxyglucose/pharmacology , Fungicides, Industrial/pharmacology , Penicillium/drug effects , Penicillium/physiology , Plant Diseases/microbiology , Agriculture/methods
17.
Commun Agric Appl Biol Sci ; 75(4): 733-9, 2010.
Article En | MEDLINE | ID: mdl-21534484

The behaviour of Penicillium digitatum and P. italicum was investigated when subjected to different concentrations of methanol (MeOH) and dimethyl sulfoxide (DMSO). The experiments were performed in 9 cm Petri dishes containing PDA amended with 0, 5, 10, 20, 30, 40 or 50 microL/mL of each of the single or combined chemicals. Daily, the formed colonies (cfu), the colony diameter and the degree of sporification were monitored during incubation at 20 degrees C for 5 day. Additionally, the pathogen development and its performance were studied by scanning electron microscopy (SEM). According to the chemical, the mycelium growth rate was affected differently and, compared to the control, only MeOH inhibited the expansion of the colony diameter. This effect was more pronounced for P. italicum. A nearly linear drop of cfu was observed as the concentration of the two chemicals was raised, and a complete inhibition of the two pathogens was attained with 50 microL/mL MeOH. With respect to the sporification degree the two pathogens were influenced similarly, but the tested compounds had opposite effects. Indeed, with MeOH, sporification took place earlier (24-36 h postinoculation) compared to the control (60 h), while during the whole experiment, DMSO at concentrations higher than 0.5 microL/mL, drastically inhibited the sporification. SEM observations of P. digitatum growth on DMSO amended media evidenced a marked increase of mycelium branching and alterations to the conidiophore, while MeOH reduced the mycelium length and fastened the conidiophore formation. The combination of the two compounds produced a synergistic interaction reducing by 40% the concentration required to inhibit completely the germination and growth of P. digitatum.


Citrus/microbiology , Fungicides, Industrial/pharmacology , Penicillium/growth & development , Plant Diseases/microbiology , Penicillium/drug effects , Spores, Fungal/drug effects , Spores, Fungal/growth & development
18.
Commun Agric Appl Biol Sci ; 75(4): 741-5, 2010.
Article En | MEDLINE | ID: mdl-21534485

'Coscia' is an early ripening pear with a short postharvest Life (1 month) and chemical treatments to prevent decay are generally not undertaken. This, along with the fast deterioration under shelf-life conditions, makes it difficult to contain postharvest moulds. 1-methylcyclopropene (1-MCP) has been employed with success to delay ripening and, as a co-effect, the development of decay was contained, but this treatment is not allowed for organically grown crops. Here we report the results of an alternative approach employing immersion treatments in water at 45, 50, 55 or 60 degrees C for 0 (control), 15, 30, 45 or 60 sec. Fruit was harvested after the climacteric peak, immediately subjected to the heat treatment and stored for 2 weeks at 1 degrees C followed by a 3 days of a simulated shelf-life at 17 degrees C and 75% RH. Half of the fruit was wounded (3 x 3mm) and inoculated with Penicillium expansum (20 microL of 10(4) conidia mL(-1). Decay inhibition and fruit appearance, rated from 0 to 3 (0 = excellent; 1 = good; 2 = scarce; 3 = not marketable), were monitored and compared to the control after storage and shelf-life. All heat treatments affected the mould development when performed for 45 or 60 sec. The best result in terms of decay control and appearance after storage and shelf-life occurred when fruit was immersed at 55 degrees C for 60 sec with a decay reduction of about 85% compared to control (75% decay) and with a good appearance.


Food Preservation/methods , Fruit/microbiology , Penicillium/growth & development , Pyrus/microbiology , Food Handling , Food Preservation/instrumentation , Hot Temperature
19.
Commun Agric Appl Biol Sci ; 75(4): 747-52, 2010.
Article En | MEDLINE | ID: mdl-21534486

'Miali' and 'Caddina' are apple varieties of Sardinian germplasm, mainly produced under sustainable conditions. Fruit is rarely subjected to cold storage and postharvest losses are generally high. In order to prolong the marketing period and contain postharvest decay of these local varieties, we investigated on their storage behaviour and on the efficacy of combined alternative postharvest treatments. Pre-climateric fruit was harvested and immersed for 0 (control), 15, 30, 45 or 60 sec. in water at 20, 50, 55 or 60 degrees C with or without 2% (W/V) NaHCO3 (SBC). Then, fruit was stored for 4 months at 5 degrees C and 90% RH followed by a 6 day simulated marketing period (SMP) at 10 degrees C and 75% RH. Decay was monitored at the end of storage and after the SMP, while appearance and physiological disorders were evaluated after SMP. During storage 56 and 62% of the untreated 'Caddina' and 'Miali' apples rotted, respectively. During the SMP, an additional 3% of 'Caddina' and 5% of 'Miali' was lost. Among the treatments the best decay control, for both varieties, was attained when fruit was immersed in the SBC solution at 55 degrees C for 60 sec. Compared to control, decay was reduced by 91 and 95% for 'Caddina' and 'Miali', respectively. This combination induced some rind damage, mainly on 'Caddina' fruit. Superficial scald was evident on 'Caddina' and scored as medium while, cold storage induced a significant deposition of epicuticular wax in 'Miali' fruit, affecting significantly fruit appearance. A significant reduction of decay was also achieved when fruit was immersed at 60 degrees C for 30 or 45 sec., attaining for 'Caddina' a reduction of 82 and 88% of decay, respectively. Other combinations were lesser effective or produced rind damages and most decay was caused by Penicillium expansum.


Food Preservation/methods , Fruit/microbiology , Malus/microbiology , Sodium Bicarbonate/pharmacology , Food Handling , Food Preservation/instrumentation , Fruit/drug effects , Hot Temperature , Malus/drug effects , Penicillium/drug effects , Penicillium/physiology
20.
Commun Agric Appl Biol Sci ; 75(4): 753-9, 2010.
Article En | MEDLINE | ID: mdl-21534487

Storage behaviour of 'Core', 'Core Columbu', 'Fradis' and 'Meloni' white prunes, and a black one ('Sighera') of Sardinian germplasm were evaluated following immersion for 0 (control), 15, 30, 45 or 60 sec in water at 20, 50, 55 or 60 degrees C with or without 2% (w/v) NaHCO3 (SBC). As international varieties, fruit from one white plum ('Shiro') and one black prune ('Stanly') were subjected to the same treatments. Fruit was harvested at commercial maturity, treated and then stored for 1 month at 5 degrees C and 90% RH followed by a simulated marketing period at 20 degrees C and 80% RH for 6 days. Fruit appearance, external damage, firmness and decay percentage were monitored after storage and SMP. Treatments did not induce rind damage (browning or discoloration) to any variety. SBC at 20, 45, 50 or 55 degrees C for 15 or 30 sec was not effective in controlling decay and compared to controls no improvement was observed. Immersion for 45 or 60 sec with SBC at all temperatures improved decay control with respect to controls and best results were obtained at 50 or 55 degrees C. Immersions at 60 degrees C improved decay control, but differences were not significant compared to the control attained with solutions of SBC heated at 55 degrees C. The overall appearance of 'Core', 'Core Columbu', 'Fradis' and 'Shiro' decreased significantly after the SMP period, especially when treated at 55 or 60 degrees C for 60 sec. Fruit shrivel was the main cause of the low rating. SBC did not affect shrivel indicating that heat treatment may be the probable cause. In general, local varieties were less affected by decay than other varieties and they performed well during storage.


Food Preservation/methods , Fruit/microbiology , Prunus/microbiology , Sodium Bicarbonate/pharmacology , Ascomycota/drug effects , Ascomycota/physiology , Food Handling , Food Preservation/instrumentation , Fruit/drug effects , Hot Temperature , Italy
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