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Impact of bacterial spot outbreaks on the phytosanitary quality of tomato and pepper seeds 
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下载免费PDF全文 The impact of disease outbreaks on the phytosanitary quality of seeds was investigated for two pathosystems: tomato–Xanthomonas vesicatoria and pepper–Xanthomonas euvesicatoria. This study, which was performed in Italy and Serbia, aimed to evaluate the season‐to‐season transmission of phytopathogenic regulated bacteria associated with phytosanitary risks posed by seeds produced in areas where bacterial infections are possible. For each pathosystem, field plots were experimentally inoculated to simulate an initial infection rate of 1%, 5% and 15%. The area under the disease progress curve (AUDPC) was calculated for each field plot, the seeds produced were analysed to determine the contamination level and rate, and the plant‐to‐seed transmission was evaluated by a seedling grow‐out (SGO) assay. To investigate transmission under field conditions, a second‐year experiment was performed, wherein seeds collected from the first year were used to establish new field plots. During the first growing season, AUDPC values were positively correlated with the percentages of initial infection for each pathosystem. Seed contamination levels in pepper ranged from 34 to 100 CFU g?1, and the contamination rate ranged from 1.50% up to 3.17% for X. euvesicatoria, whereas processing and fresh market tomato seeds produced both in Italy and Serbia were not infected by X. vesicatoria. During SGO assays and the second cropping year, no symptoms were observed in either tomato or pepper plants. Therefore, the calculated pepper seed contamination rate for X. euvesicatoria appeared to be less than the threshold necessary to initiate a disease outbreak. Finally, all seeds obtained during the second cropping year were uninfected. 相似文献
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Michael J. De Lasaux Raffaele Spinelli Bruce R. Hartsough Natascia Magagnotti 《Small-Scale Forestry》2009,8(3):367-379
The Authors tested a mobile small-log sawmill system that could produce cants and boards of variable size, according to the
needs and specifications of each property owner. The unit was deployed as part of a comprehensive mechanical fuel reduction
operation, aimed at thinning small properties around homesteads. Working on conifer small logs, the mill proved very efficient,
with a processing productivity between 0.3 and 2.8 m3 of lumber per working hour and a recovery rate of 50% for boards, and 67% for cants. The mill could be set up and dismantled
in a few hours and was easy to move around. However, the exceedingly small amount of logs available at each site entailed
a low utilization of the mill (about 25% of the time) and a consequently high processing cost. Under the conditions of the
study, milling cost can be contained below 150 US dollars per m3 of lumber only if the single site offers at least 50 m3 of logs, already sorted during harvesting. Hence the suggestion of pooling the wood obtained from small parcel fuel reduction
treatments in satellite yards and milling it only when a large enough amount has been accumulated. In turn, satellite yards
could be organized into an integrated network complementary—rather than alternative—to stationary mills. 相似文献
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Diego A Portela Pablo E Otero Martina Biondi Marta Romano Simonetta Citi Tommaso Mannucci Angela Briganti Gloria Breghi Carlos Bollini 《Veterinary anaesthesia and analgesia》2013,40(6):e91-e99
ObjectiveTo determine the needle‐to‐nerve distances during electrical nerve location in dogs at different currents and pulse duration using a peripheral nerve stimulator (PNS) under ultrasound control (US), and the minimal electrical thresholds (MET) necessary to obtain a motor response (MR) after achieving needle‐to‐nerve contact.Study designProspective in vivo experimental trial in a clinical settingAnimalsThirty dogs, scheduled for locoregional anaesthesia of the sciatic nerve.MethodsNeedle‐to‐nerve distance was measured ultrasonographically after obtaining the MR of sciatic nerve with 2, 1 and 0.5 mA and pulse duration 0.1 ms (NS0.1). Thereafter the needle was placed in contact with the nerve and MET was determined. The procedure was repeated with 0.3 ms (NS0.3). Finally the needle was reintroduced to contact the sciatic nerve guided only by US, thus MET‐US was determined. Data were analysed using Kruskal–Wallis or Mann–Whitney tests.ResultsNeedle‐to‐nerve distances were greater when MR was obtained with 2 mA than with 1 and 0.5 mA at 0.1 and 0.3 ms. No significant differences were observed between the needle‐to‐nerve distances using 0.1 or 0.3 ms.The MET [median (range)] was 0.4 (0.18–1.3) mA in NS0.1, 0.32 (0.12–0.8) mA in NS0.3; while MET‐US was 0.7 (0.32–1.5) mA. When the needle contacted the nerve, the MR achieved with currents below 0.3 mA was obtained in 17.2, 40 and 0% of cases using NS0.1, NS0.3 and US respectively.Conclusions and clinical relevanceThe electrical current necessary to obtain a MR decreased as the needle moved towards the nerve. However when the needle tip contacted the nerve, an MR with low current intensity could not be obtained. Thus the absence of motor response at currents below 0.3 mA cannot rule out needle‐epineurium contact. When ultrasound is combined with PNS, it is more important to assess the correct needle position than searching for an MR at low currents. 相似文献
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Spinelli Raffaele Magagnotti Natascia Visser Rien O’Neal Brandon 《European Journal of Forest Research》2021,140(4):901-911
European Journal of Forest Research - As a generalization, harvested timber is extracted from forests either as trees or stems by skidders or as logs by forwarders. Coupled with harvesters,... 相似文献
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Replacing Steel Cable with Synthetic Rope to Reduce Operator Workload During Log Winching Operations
The authors conducted three comparative tests, to determine if the replacement of steel cable with synthetic rope may allow
reducing the physiological workload of forest operators assigned to log winching tasks. The tests were conducted in Northern
Italy, on the Alpine mountain and involved 7 volunteer subjects. The physiological workload was determined by measuring the
operator’s heart rate upon completion of every task, using heart-rate monitors. Test one was conducted under simplified, controlled
conditions and detected a statistically significant reduction of relative heart rate when carrying synthetic rope, as compared
to steel cable. However, tests two and three were performed under real operational conditions, and were inconclusive. Real
operational conditions are characterized by the interaction of many factors, which may confound the results of the tests,
or offset the benefits potentially obtained with the introduction of synthetic rope. Nevertheless, the introduction of synthetic
rope offers the benefit of easier handling, which was very much appreciated by all test subjects. 相似文献
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Foraging behaviour of the parasitoid Eretmocerus eremicus under intraguild predation risk by Macrolophus pygmaeus 下载免费PDF全文
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