Macro-nutrient uptake dynamics in greenhouse tomato crop

This study verified the concentration over time of nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur (N, P, K, Ca, Mg, and S) in the leaves, stems, fruits, and roots of tomato plants. An indeterminate growth variety with ball-type fruits suited for greenhouse cultivation was used. The results showed that the distribution of minerals in the different organs of the plant varies over time. The minerals N, P, and K showed a tendency to decrease their concentration, while the concentration of Ca and S increased and that of Mg remained constant over time. The leaves had the highest concentrations of N, P, K, Ca, and Mg. The concentrations of K, for both leaf and stem, ranged between 20 and 30 g kg^?1. N and K were the most extracted minerals, while P was the least extracted mineral. The information presented in this paper allows a better fertilization plan for growing tomatoes inside greenhouses.     

Breadmaking Quality of Selected Durum Wheat Genotypes and Its Relationship with High Molecular Weight Glutenin Subunits Allelic Variation and Gluten Protein Polymeric Composition

Twenty‐seven durum wheat genotypes originating from different geographical areas, all expressing LMW‐2 at Glu‐B3, and five bread wheats were evaluated for flour mixing properties, dough physical characteristics, and baking performance. Gluten polymeric composition was studied using size‐exclusion HPLC of unreduced flour protein extracts. As a group, durum wheats had poorer baking quality than bread wheats in spite of higher protein and total polymer concentrations. Durum wheats exhibited weaker gluten characteristics, which could generally be attributed to a reduced proportion of SDS‐unextractable polymer, and produced less extensible doughs than did bread wheats. However, substantial variation in breadmaking quality attributes was observed among durum genotypes. Better baking performance was generally associated with greater dough extensibility and protein content, but not with gluten strength related parameters. Extensibility did not correlate with gluten strength or SEHPLC parameters. Genotypes expressing high molecular weight glutenin subunits (HMW‐GS) 6+8 exhibited better overall breadmaking quality compared with those expressing HMW‐GS 7+8 or 20. Whereas differences between genotypes expressing HMW‐GS 6+8 and those carrying HMW‐GS 7+8 could only be attributed to variations in extensibility, the generally inferior baking performance of the HMW‐GS 20 group relative to the HMW‐GS 6+8 group could be attributed to both weaker and less extensible gluten characteristics.     

Responses of Aerobic Rice （Oryza sativa L.） to Iron Deficiency

Aerobic rice has the advantage of saving water.Most published work has focused on improving its yield,while few reported on its micronutrient status.In fact,Fe deficiency is a common nutritional proble...     

Deep water longline selectivity for black spot seabream (<Emphasis Type="Italic">Pagellus bogaraveo</Emphasis>) in the Strait of Gibraltar

Species and size selectivity of the deep water longline traditionally used in commercial fishing of the black spot seabream (Pagellus bogaraveo) were studied in the Strait of Gibraltar with four sizes of hooks. Black spot seabream contributed up to 88% of the catch by number. Catch and by-catch rates differed for the different hooks and fishing trials. Significant differences in average fish length between all hooks, except in one case, were found. The comparison of two experimental fishing trials within 4 years indicates a displacement towards smaller sizes in the size frequency distributions. The results of this study show that the fishing gear can be size selective depending on hook size. The fitted selectivity models for each experiments were very different despite having two hooks in common. This is probably due to the very different catch size distributions in the two periods, which suggests that the population size structure changed significantly between 2000/2001 and 2004/2005.     

The impacts of integrated homestead pond‐dike systems in relation to production,consumption and seasonality in central north Bangladesh

The roles of homestead ponds and surrounding dike production of vegetables on farms in peri‐urban and rural communities in central north Bangladesh were assessed. A baseline survey sought to characterize actively managed (“active”) pond‐dike systems, producing fish and vegetables, in terms of productivity and impact compared to less intensively integrated (“passive”) and control, no‐pond households. A longitudinal survey was carried out over 12 months to explore the relationship between seasonality and livelihood outcomes in relation to location and well‐being status. Active homestead pond operators tended to have greater access to information and credit compared to passive and non‐pond households; this was likely linked to their greater literacy and greater social connectedness. They enjoyed higher incomes through fish sales and consumed more fish than passive households, which was related to their higher production, in turn explained mainly by the use of more inputs. All active, 50% passive and 38% non‐pond households were involved in vegetable cultivation; however, significantly more vegetables were produced by active households than others. The impacts of pond‐dike production were more critical for food‐vulnerable, rural households than peri‐urban households prior to monsoon rice harvest; worse‐off households suffered more prior to the “irrigated rice” harvest. Fish and vegetables raised on farm were most important during lower income months. The study supports the view that small homestead ponds can contribute to the wider food supply, and that such “quasi‐peasant” forms of aquaculture contribute to reduced poverty and enhanced dietary diversity and food security in the broader population.     

A conservation trade‐off? Interspecific differences in seahorse responses to experimental changes in fishing effort

• 1. A 2‐year experimental seining programme and underwater visual censuses were undertaken to quantify the direct effects of active demersal fishing on the population structure and relative abundance of two sympatric seahorse species of conservation concern: the European long‐snouted seahorse, Hippocampus guttulatus Cuvier 1829 and the short‐snouted seahorse, Hippocampus hippocampus L. The influence of habitat preference on population‐level responses to changes in habitat structure following a reduction in fishing effort was also investigated.
• 2. It was predicted that the benthic habitat would be more structurally complex after fishing ceased and that seahorse densities would increase in response to reduced fishing mortality. Furthermore, it was predicted that the magnitude of the increase in density would be greater for H. guttulatus than for H. hippocampus, because the former species prefers complex vegetated habitats while the latter species uses sparsely vegetated habitats.
• 3. As predicted, the amount of habitat cover increased significantly when seining ceased, primarily through increases in the abundance of drifting macroalgae and unattached invertebrates. Despite similarities in life histories, the two seahorse species responded differently in terms of magnitude and direction to reduced fishing effort: the abundance of H. guttulatus increased significantly while H. hippocampus decreased in abundance.
• 4. Results suggest that active demersal fishing may influence the magnitude and direction of the responses of benthic marine fishes to exploitation through its impacts on habitat structure. An increase in habitat cover appeared to favour higher densities of H. guttulatus when seining effort was reduced. By contrast, repeated seining, which maintained less complex habitats, appeared to favour greater abundances of H. hippocampus.
• 5. Given differences in habitat preference among benthic marine fishes subject to incidental capture in fisheries, simultaneous attempts to manage populations of sympatric species may require complementary strategies that support the persistence of diverse habitat types.

Copyright © 2006 John Wiley & Sons, Ltd.     

配方施肥对库尔勒香梨果实品质及叶片矿质营养含量的影响

[目的]研究配方施肥对库尔勒香梨果实品质及叶片矿质营养含量的影响,以15、16生库尔勒香梨树为材料,分别进行1年、2年配方施肥处理,分析配方施肥不同年限处理对香梨果实品质及叶片矿质营养含量变化的影响.[方法]香梨树秋季开沟进行配方施肥.所用肥料为羊粪,生物黑炭,粒状重过磷酸钙,硫酸钾按,尿素按,微量元素,配方施肥1年、2年果实成熟期分别取样.[结果]配方施肥能提高果实中VC含量和还原糖的含量,降低果实中的总酸含量及果实的硬度,改善果实品质;配方施肥处理能提高叶片营养元素的含量,其中配方施肥2年效果明显.各处理之间有着显著差异,施肥效应表现为:配方2＞配方3＞配方1＞CK.[结论]配方施肥2年配方2处理效果最好.     

Influence of Carotino oil on in vitro rumen fermentation,metabolism and apparent biohydrogenation of fatty acids

The study appraised the effects of Carotino oil on in vitro rumen fermentation, gas production, metabolism and apparent biohydrogenation of oleic, linoleic and linolenic acids. Carotino oil was added to a basal diet (50% concentrate and 50% oil palm frond) at the rate of 0, 2, 4, 6 and 8% dry matter of the diet. Rumen inoculum was obtained from three fistulated Boer bucks and incubated with 200 mg of each treatment for 24 h at 39°C. Gas production, fermentation kinetics, in vitro organic matter digestibility (IVOMD), volatile fatty acids (VFA), in vitro dry matter digestibility (IVDMD), metabolizable energy and free fatty acids were determined. Carotino oil did not affect (P > 0.05) gas production, metabolizable energy, pH, IVOMD, IVDMD, methane, total and individual VFAs. However, Carotino oil decreased (P < 0.05) the biohydrogenation of linoleic and linolenic acids but enhanced (P < 0.05) the biohydrogenation of oleic acid. After 24 h incubation, the concentrations of stearic, palmitic, pentadecanoic, myristic, myristoleic and lauric acids decreased (P < 0.05) while the concentration of linolenic, linoleic, oleic and transvaccenic acids and conjugated linoleic acid (CLAc9t11) increased (P < 0.05) with increasing levels of Carotino oil. Carotino oil seems to enhance the accumulation of beneficial unsaturated fatty acids without disrupting rumen fermentation.     

Prevalence of Coxiella burnetii antibodies in Portuguese dairy cattle herds

Q fever is an important zoonotic disease which has been recently diagnosed, mainly in sheep and goats, in Portugal. The aim of the present study was to determine the prevalence of bovine Coxiella burnetii antibodies in dairy farms from the northwest of Portugal. Bulk tank milk samples were randomly obtained, on November 2013, from 90 dairy farms and assayed using an ELISA kit. The apparent prevalence was 61.1 % (95 % C.I. from 50.8 to 70.5 %). The proportion of negative and intermediate (inconclusive) herds was 34.5 % (25.5 to 44.7 %) and 4.4 % (1.7 to 10.9 %), respectively. In conclusion, a high level of exposure to Coxiella burnetii was observed in Portuguese dairy cattle herds, highlighting the needs to better understand the epidemiology of Q fever in Portugal by the implementation of a monitoring program based on harmonized serologic and molecular methodologies and elucidation of the infection status of the herds.