Traditional leafy vegetables and their use in the Benin Republic

Seventy-three villages randomly selected in 29 ethnic areas and three regions or agro-ecological zones of Benin were investigated by a participatory rural appraisal survey to assess the diversity of the species used as traditional leafy vegetables (TLVs). In total, 187 plant species belonging to 141 genera and 52 families were recorded. Among these, 47 (25.13%) were cultivated and 140 (74.87%) were gathered from the wild. Herbs (64.78%) were the most numerous followed by shrubs (19.78%) and trees (15.50%). The Shannon–Weaver diversity index calculated was 3.232. The total number of TLVs used highly varies, across ethnic groups, from 15 (Toli tribe) to 58 (people Mahi) with, on average, 36 species per ethnic group. The relative proportions of the wild and cultivated species used also vary with the tribes but on average appeared almost the same. Of the species inventoried, 18 of national importance were found among which Solanum macrocarpon, Corchorus olitorius, Amaranthus cruentus and Gymnanthemum amygdalinum ranked first. The matrix scoring technique yielded 12 criteria of different natures used to define preference. Among these, four (taste, ease of preparation, availability and quantity of required condiments) were the most important and represent, all together, more than 72% of responses. Despite the diversity of species used as leafy vegetables, they were all basically consumed in the same way. Sauces were the main type of preparation and involved all the species. The perceived nutritional and medicinal (curative, regulative and stimulative) properties of the species as well as their cultural significance were documented. Some TLVs are known and consumed by all or many ethnic groups while many others were simply ethnospecific or used by only a few peoples. However, no correlation was found between the distribution of the utilisation of the species and their degree of consumption which all depend on the eating habits of the peoples. Cluster analysis revealed that peoples sharing a common geographical space and/or cultural identity or origin seem to consume almost the same types of TLVs and cluster together. Given the large quantity of evidence of the importance of the TLVs, there should be a systematic effort to improve their understanding and their uses to reduce if not alleviate rural poverty and malnutrition in Benin.     

Nitrate contents in some vegetables in Tunisia

This study reports the nitrate level of 22 vegetables species collected from 40 farms in several locations of an intensive agricultural area in two regions of Tunisia (Sousse and Monastir). Nitrate levels ranged between 57 and 2970 mg kg^?1. The highest and the lowest levels were found in turnip and tomato, respectively. Only five species (potato, field bean, cauliflower, pea and artichoke) had exceeded the norms established by the World Health Organization. Factors influencing nitrate accumulation in some vegetables were analyzed and discussed. It was observed that nitrate contents in vegetables varied depending on the type of vegetables, genetic factor, level of nitrogen fertilization and soil nitrogen content.     

Phosphorus Fertility Assessment of Intensively Farmed Areas of Catchments Draining to the Great Barrier Reef World Heritage Area; 1: Soil Phosphorus Status

Abstract

Australia's reef water quality protection plan has a key objective: “reduce the load of pollutants from diffuse sources in the water entering the Reef.” This article reports on a survey to assess the contemporary phosphorus (P) status of fertilized cropping soils across 21 catchments in coastal Queensland, Australia. The survey focused on surface soils from cane farms, vegetable and subtropical/tropical fruit tree sites. There were sampling depth effects on P levels in sugar and fruit tree sites (lower with depth). Importantly, 84% of 105 sugarcane sites were excessively fertile and only 3% rated low (P deficient). Some 75% of 16 vegetable sites and 38% of 8 fruit tree sites had excess ratings for extractable soil P fertility. Highest total P levels (0–10 cm) occurred in fruit tree sites, followed by vegetable and sugarcane soils. There are regional differences in P soil fertility, and the recycling of mill by‐products needs attention. Part 2 (Bloesch and Rayment 2006 Bloesch, P. M. and Rayment, G. E. 2006. “Phosphorus fertility assessment of intensively farmed areas of catchments draining to the Great Barrier Reef World Heritage Area, 2: Potential of soils to release soluble phosphorus”. In Communications in Soil Science and Plant Analysis 37 [Google Scholar]) examines the potential of these soils to release soluble P in a nutrient‐sensitive area.     

无公害农产品（种植业）认证信息登录系统设计思路与应用实践

介绍无公害农产品（种植业）认证信息登录系统的设计与应用,并对系统的各功能模块进行了说明。系统在实际应用中,能够保障信息传输的高效和安全,并对信息数据进行标准化和动态统计分析,有效地提高信息传输能力和利用率。对目前系统的不足之处提出了进一步完善的建议。     

混联式太阳能果蔬烘干机的研制

为了解决新疆地区传统果蔬干制工艺存在的问题,提高农产品加工质量,根据该地区的气候特点及农产品特点,确定了混联式太阳能果蔬烘干机的总体结构方案,完成了集热、控制和烘干等主要系统设计计算、参数设定,成功进行了葡萄烘干试验,通过葡萄烘干试验表明,比传统干燥方式缩短时间66.7%,绿级品率由低于35%提高到79.19%,该设备可提高新疆农产品的干制效率,促进该地区农业的发展。     

Protozoan predation of Escherichia coli in hydroponic media of leafy vegetables

Multiple outbreaks of food poisoning associated with fresh vegetable consumptions have occurred in many countries. Numerous reports have described human pathogenic bacteria, such as Escherichia coli O157:H7 and Salmonella spp., that can internalize into fresh vegetables via root or leaf surfaces. While attempting to obtain the threshold concentration of internalization of E. coli inoculated into hydroponic medium during vegetable cultivation, we observed a rapid decrease in E. coli numbers. In the present study, we determined that the rapid decline in E. coli was not due to a physiological change into a viable but non-culturable (VNC) state. The population crash was instead caused by true bacterial death, as the rapid descent was also confirmed by micro-colony fluorescence in situ hybridization, a culture-independent method that can detect VNC cells. We next monitored the number of E. coli inoculated into intact or filter-sterilized hydroponic medium after cultivation of various types of plants. We found that the number of E. coli in intact hydroponic medium decreased markedly, whereas the level in filter-sterilized hydroponic medium was completely unchanged. This result suggests that biotic factors were present that could be eliminated by filtering. Robust predation of E. coli by protozoa (ciliates and flagellates) was observed using fluorescently labeled bacteria incorporated into the hydroponic medium. Finally, morphological identification of flagellates by scanning electron microscopy revealed the presence of a species of Stramenopiles. These findings suggest the importance of protozoa as bacterial feeders in hydroponic systems and hence the use of these organisms as potential control agents of human pathogenic bacteria.     

温室蔬菜病虫害防治

阐述了温室蔬菜病虫害发生的原因,从高温闷棚、土壤消毒、栽培管理、生态防治等方面探讨了温室蔬菜病虫害防治的策略。     

植物精油在果蔬保鲜中的应用

植物精油多提取于香辛料及中草药植物的花、叶、茎、根或果实,具有显著的抑菌效果,且安全无毒,是一种理想的天然果蔬保鲜剂。通过对植物精油的抑菌活性、果蔬防腐保鲜的作用及其机理等方面进行综述及分析可知,植物精油的开发利用必将迎来更加广阔的前景。     

和龙市林业局龙牙楤木的开发利用

龙牙楤木是享誉长白山地区最著名的木本山野菜之一,除了食用价值,还兼有补气安神、强精滋肾的药用价值。由于当地广大群众一直实行掠夺性的采摘方法,致使野生龙牙楤木资源受到严重破坏,其蕴藏量和可采量逐年减少,供需矛盾日渐突出;为保护当地濒危经济植物———龙牙楤木,采取必要的保障措施,综合开发利用,才能使龙牙楤木产业真正成为和龙市多种经营的重要来源之一。     

果蔬压缩力学性质与细观结构变位的动态响应

研究果蔬的压缩力学性质可为果蔬加工、运输、检测包装等生产环节提供设计参数及工艺优化依据。为此,以几种常见果蔬为研究对象,在INSTRON生物材料性能试验机上搭载了电子显微镜图像采集系统,在进行果蔬试样压缩力学性质试验测试的同时,对压缩变形过程进行了动态图像采集与分析,获得了果蔬的压缩强度极限、弹性模量等力学性质指标。同时,结合电子显微镜采集到的压缩过程果蔬细观结构变形图像,通过观察压缩过程果蔬细胞的变形、微结构变位及渗水等情况,分析了果蔬材料的屈服强度、压缩强度及材料破坏与细观结构变位的关联,了解了果蔬压缩力学性质与压缩过程中细观结构变位的动态响应。