Deficit irrigation and rootstock: their effects on water relations, vegetative development, yield, fruit quality and mineral nutrition of Clemenules mandarin

Differences between rootstocks, 'Cleopatra' mandarin and 'Carrizo' citrange, in soil-plant water relations and the influence of these factors on vigor, crop yield, fruit quality and mineral nutrition were evaluated in field-grown Clemenules mandarin trees irrigated at 100% of potential seasonal evaporation (ET(c)) (control treatment), or irrigated at 100% ET(c), except during Phases I and III of fruit growth and post-harvest when no irrigation was applied (deficit irrigation (DI) treatment), for 3 years. Differences between rootstocks in plant-soil water relations were the primary cause of differences among trees in vegetative development and fruit yield. After 3 years of DI treatment, trees on 'Cleopatra' showed more efficient soil water extraction than trees on 'Carrizo', and maintained a higher plant water status, a higher gas exchange rate during periods of water stress and achieved faster recovery in gas exchange following irrigation after water stress. The DI treatment reduced vegetative development more in trees on 'Carrizo' than in trees on 'Cleopatra'. Cumulative fruit yield decreased more in DI trees on 'Carrizo' (40%) than on 'Cleopatra' (27%). The yield component most affected by DI in 'Cleopatra' was the number of fruit, whereas in 'Carrizo' it depended on the severity of water stress reached in each phase (severe water stress in Phase I affected mainly the number of fruit, whereas it affected fruit size the most in Phase III). In the third year of DI treatment, water-use efficiency decreased sharply in trees on 'Carrizo' (70%) compared to trees on 'Cleopatra' (30%). Thus, trees on 'Cleopatra' were able to tolerate moderate water stress, whereas trees on 'Carrizo' were more sensitive to changes in soil water content.     

熏蒸剂的使用受限促进气调技术的发展

熏蒸药剂残留对食品、环境的危害问题使得相关标准制定单位采取措施严格限制熏蒸剂的使用.二十年前曾经使用的多数熏蒸剂如今已所剩无几.甲基溴具有较高效的杀虫效果,但是由于它对臭氧层的破坏严重,发达国家已于2005年淘汰使用,发展中国家也将于2015年之前淘汰甲基溴.比较而言,现今使用普遍的仍是磷化氢,然而近年来害虫对磷化氢的抗性问题显得日益严重.这些熏蒸药剂的种种局限,已经向食品企业提出了新的全球性的挑战,要求致力于寻找新的熏蒸剂,开发新的替代技术.目前,被提及的新的熏蒸剂有硫酰氟、氧硫化碳(carbonyl sulphide)、环氧丙烷(propylene oxide)、甲基碘(methyl jodide)、臭氧(ozone)、甲酸甲酯(ethyl formate)和氢氰酸(hydrogen cyanide).硫酰氟被认为是很有前景的熏蒸剂替代品,可用来有效地保护储藏食品、食品加工设备免受害虫危害,而且还可以作为一种检疫用的熏蒸剂.其它一些新开发的熏蒸剂由于只对特定种类的储藏物品有效或在特定条件下才有效,所以使用的局限性很大.试验证明:具有挥发性的植物提取剂有较好的使用前景,但还需要大量的商业生产验证试验,而且在投入生产实践之前还需要一系列的认证程序.可成功替代熏蒸药剂的众多气体处理技术有:气调技术、高温结合气调技术以及进一步开发用作特定用途的高压二氧化碳技术.当前研究开发的是低压环境下的气调技术.这些研究证明气调技术很有市场前景,应当作为全球开发的新方法的一个典范.     

The comparative pathology of enterocolitis caused by Clostridium perfringens type C,Clostridioides difficile, Paeniclostridium sordellii,Salmonella enterica subspecies enterica serovar Typhimurium,and nonsteroidal anti-inflammatory drugs in horses

To determine if there were significant differences produced by 5 of the most prevalent causes of equine enterocolitis, we studied retrospectively the gross and microscopic pathology of 90 cases of enterocolitis submitted to the San Bernardino laboratory of the California Animal Health and Food Safety Laboratory. Included were cases caused by Clostridium perfringens type C (CP; n = 20), Clostridioides difficile (CD; n = 20), Paeniclostridium sordellii (PS; n = 15), Salmonella enterica subspecies enterica serovar Typhimurium (ST; n = 20), and NSAID intoxication (NS; n = 15). Grossly, necrotizing hemorrhagic typhlocolitis was seen most frequently in cases of CD, ST, and NS disease. Cases of CP and PS had enteritis or colitis in similar percentages. Congestion, hemorrhage, and pleocellular inflammatory infiltrates followed by mucosal and submucosal necrosis were the main lesions found in horses with enteritis or colitis produced by any of the etiologic agents investigated. Severe lesions were more frequent in cases of CD and CP than in cases associated with any of the other 3 etiologies. Pseudomembranes were observed with similar prevalence in the small intestine and colon affected by all agents studied. Thrombosis of the lamina propria and/or submucosa was observed in ~50% of the cases of enteritis and colitis by all etiologies, except for PS, in which the majority of the cases had thrombosis. Gross and microscopic lesions of enterocolitis were not sufficiently specific for any of these etiologic agents to enable these enteritides to be distinguished by gross and/or histologic examination.     

Movements and diving behaviour of white-chinned petrels: Diurnal variation and implications for bycatch mitigation

1. Many seabirds dive to forage, and the ability to use this hunting technique varies according to such factors as morphology, physiology, prey availability, and ambient light levels. Proficient divers are more able to seize sinking baits deployed by longline fishing vessels and may return them to the surface, increasing exposure of other species. Hence, diving ability has major implications for mitigating incidental mortality (bycatch) in fisheries.
2. Here, the diving behaviour and activity patterns of the most bycaught seabird species worldwide, the white-chinned petrel (Procellaria aequinoctialis), tracked from Bird Island (South Georgia), are analysed. Three data sources (dives, spatial movements, and immersion events) are combined to examine diverse aspects of at-sea foraging behaviour, and their implications for alternative approaches to bycatch mitigation are considered.
3. The tracked white-chinned petrels (n = 14) mostly performed shallow dives (<3 m deep) of very short duration (<5 s), predominantly during darkness, but only 7 and 10% of landings in daylight and darkness, respectively, involved diving, suggesting that surface-seizing is the preferred foraging technique. Nonetheless, individuals were able to dive to considerable depth (max = 14.5 m) and at speed (max = 2.0 m·s⁻¹), underlining the importance of using heavy line-weighting to maximize hook sink rates, and bird-scaring lines (Tori lines) that extend for long distances behind vessels to protect hooks until beyond diving depths.

     

Intake and food sources of nitrites and N-nitrosodimethylamine in Spain

OBJECTIVE: To conduct a comprehensive assessment of dietary intakes of nitrites and N-nitrosodimethylamine (NDMA). SUBJECTS AND SETTING: A study was conducted within the Spanish cohort of the European Prospective Investigation in Cancer and Nutrition (EPIC) to assess the intake and food sources of these compounds in Spanish adults. The study included 41,446 health volunteers, aged 29-69 years, from Northern and Southern regions. Usual food intake was estimated by in-person interviews using a computerised dietary questionnaire. RESULTS: The estimated geometric mean was 0.994 mg day(-1) for nitrites and 0.114 microg day(-1) for NDMA. For both compounds a positive trend in consumption with increasing energy intake was observed. Dietary NDMA was related to age and sex after energy adjustment, while nitrite consumption increased with higher intakes of vitamin C (P < 0.001). The food groups that contributed most to intakes were meat products, cereals, vegetables and fruits for nitrites, and processed meat, beer, cheese and broiled fish for NDMA. Current and past smokers, who had high levels of NDMA from tobacco exposure, were also identified as the highest consumers of dietary NDMA. Furthermore, smokers had low intakes of vitamin C (an inhibitor of endogenous nitrosation). CONCLUSIONS: Intake levels of NDMA and nitrites in a Mediterranean cohort are currently relatively lower than those previously reported, although processed meat, beer and cured cheese still are the most important contributors to NDMA intake.     

Behavior of myclobutanil, propiconazole, and nuarimol residues during lager beer brewing

Over a 4 month brewing process, the fate of three fungicides, myclobutanil, propiconazole, and nuarimol, was studied in the spent grain, brewer wort, and final beer product. Only the residual level of myclobutanil after the mashing step was higher than its maximum residue limit (MRL) on barley. A substantial fraction was removed with the spent grain in all cases (26-42%). The half-life times obtained for the fungicides during storage of the spent grains ranged from 82 to 187 days. No significant influence of the boiling stage on the decrease of the fungicide residues was demonstrated. During fermentation, the content reduction varied from 20 to 47%. After the lagering and filtration steps, no significant decrease (<10%) was observed in any of the residues. Finally, during storage of the beer (3 months), the amounts of fungicides fell by 25-50% of their respective concentrations in the finished beer.     

Discriminating significance of the free amino acid profile in almond seeds

Known statistical techniques have been applied to the free amino acid composition of 107 samples from 10 different almond cultivars (Marcona, Desmayo-Largueta, Guara, Tuono, Ferragnes, Masbovera, Non Pareil, Titan, Texas, and Primorskyi) cultivated in seven different locations and growing conditions. It is concluded that free amino acid composition can constitute a basis for classifying and typifying these cultivars into five groups: (1) Marcona and Texas, (2) Ferragnes and Masbovera (and probably Primorskyi), (3) Tuono and Guara, (4) Non Pareil (and probably Titan), and (5) an isolated cultivar (Desmayo Largueta). As a result, an easy decision tree is proposed to discriminate the cultivar of an almond flour, as used in confectionery, if it consists of a single cultivar.     

The Faustmann model as a model for a forestry of prices

The relation between the Faustmann model and “a forestry of prices” as a concept of thought was examined. At first, the meaning of the Faustmann model in economic sciences is the explanation of allocation and distribution by prices. The rotation age determination plays a secondary role only. Secondly, “a forestry of prices” as an application of the “free to choose” way of thinking is explained. The concept allows us to understand how individuals of anonymous groups achieve forest sustainability and provide forest environmental goods. Thirdly, the relation between the Faustmann model and “a forestry of prices” is discussed. For this purpose, the Faustmann model is described as a scientific laboratory. It helps us to observe how equilibrium arises as a non-intended result of individual welfare maximization in anonymous interactions. And conversely with the help of “a forestry of prices”, we understand also that the individual maximization approach of the Faustmann model re-enacts the unintended interaction situations in anonymous group. With help of the Faustmann model, we can understand deep aspects of “a forestry of prices”. Vice versa, “a forestry of prices” shows the meaning of the formal solutions of the Faustmann model.     

Somatic embryogenesis efficiently eliminates viroid infections from grapevines

Indirect somatic embryogenesis is effective at eliminating the most important viruses affecting grapevines. Accordingly, this technique was tested as a method for eradicating two widespread viroids, Grapevine yellow speckle viroid 1 (GYSVd-1) and Hop stunt viroid (HSVd), from four grapevine cultivars. Both viroids were detected by RT-PCR in grapevine floral explants used for initiating embryogenic cultures, as well as in undifferentiated cells of embryogenic and non-embryogenic calli from anthers and ovaries. In contrast, somatic embryos differentiated from these infected calli were viroid-free, and viroids were not detected in embryo-derived plantlets even 3 years after their transfer to greenhouse conditions. A wider spatial distribution of HSVd than GYSVd-1 within proliferating calli was revealed by in situ hybridization, whereas no hybridization signal was detected in the somatic embryos. In addition, GYSVd-1 and HSVd were localised in the nucleus of infected cells, conclusively showing the nuclear accumulation of representative members of Apscaviroid and Hostuviroid genera, which has been only an assumption so far. Somatic embryogenesis was compared to in vitro thermotherapy, a technique routinely used for virus eradication. After thermotherapy, HSVd and GYSVd-1 were detected in all in vitro plantlets of the cultivar Roussan, and in all lines analysed after 3 years of culture in greenhouse. The high efficiency with which somatic embryogenesis may eliminate viroids and viruses from several infected grapevine cultivars, should allow the availability of virus- and viroid-free material, which would be useful not only for sanitary selection but also for basic research on plant-virus and plant-viroid interactions in grapevine.