Potato (Solanum tuberosum L.) can be grown safety on human consumption in slight Hg-contaminated soils across China mainland.

Mercury (Hg) exposure poses serious health risks to humans, resulting in extensive investigations examining Hg accumulation, biotransformation and uptake in crops. In this investigation, Hg accumulation in potato tubers due to bioaccumulation processes was determined and bioconcentration factors affecting bioaccumulation were identified using a greenhouse experiment. Our results showed that the percentage of available Hg concentrations from total Hg in soil samples were less than 1.2%, indicating that soils used in our experiment exhibited a high binding strength for Hg, with alkaline soil recording the lowest available Hg/total Hg ratio. Results indicated that soil type and Hg treatment, as well as their interactions, significantly affected Hg accumulation in potato tubers (P < 0.01). Importantly, our results also indicated that potatoes grown in soil with a Hg concentration two times higher than the Chinese Environmental Quality Standard exhibited no obvious toxic effects on humans; Bioconcentration factors (BCF) values (<0.04) suggested that potatoes can be considered as a low Hg accumulating species and suitable for human consumption. Potato yields in acidic soil were lower than those in neutral or alkaline soils, making this medium unsuitable for growth.

Mediterranean Wild Edible Plants: Weeds or "New Functional Crops"?

The Mediterranean basin is a biodiversity hotspot of wild edible species, and their therapeutic and culinary uses have long been documented. Owing to the growing demand for wild edible species, there are increasing concerns about the safety, standardization, quality, and availability of products derived from these species collected in the wild. An efficient cultivation method for the species having promising nutraceutical values is highly desirable. In this backdrop, a hydroponic system could be considered as a reproducible and efficient agronomic practice to maximize yield, and also to selectively stimulate the biosynthesis of targeted metabolites. The aim of this report is to review the phytochemical and toxic compounds of some potentially interesting Mediterranean wild edible species. Herein, after a deep analysis of the literature, information on the main bioactive compounds, and some possibly toxic molecules, from fifteen wild edible species have been compiled. The traditional recipes prepared with these species are also listed. In addition, preliminary data about the performance of some selected species are also reported. In particular, germination tests performed on six selected species revealed that there are differences among the species, but not with crop species. "Domestication" of wild species seems a promising approach for exploiting these "new functional foods".

Monitoring and risk assessment of 74 pesticide residues in Pu-erh tea produced in Yunnan, China.

A number of 100 Pu-erh tea samples from the 2013 harvest in Yunnan Province (China) were analysed for 74 pesticides. A total of 11 pesticides were detected. At least one pesticide was detected in 56% of the samples. None of these samples contained the 74 monitored pesticides at concentrations above the Chinese maximum residual levels. Imidacloprid, bifenthrin and acetamiprid were most frequently found, with percentages of 53%, 46% and 31%, respectively. These were also the top three pesticides with maximum concentrations of 140, 246 and 672 µg kg⁻¹, respectively. Residual levels of the monitored pesticides showed no significant correlation with the production time or area of Pu-erh tea. Whereas a high incidence of pesticide residues was detected in Pu-erh tea, the contamination levels observed do not pose any serious health risks.

Dissipation kinetics of bifenazate in tea under tropical conditions.

Field experiments were conducted during April and May of 2011 in Valparai, Coonoor and Gudalur (Tamil Nadu, India) to determine the residues of bifenazate in black tea. From this study, residue levels of bifenazate at different harvest intervals, persistence, dissipation pattern during processing, rate constant and half-life values were calculated. Residues of bifenazate dissipated exponentially after spraying and at Gudalur trial, on the 16th day after application residues were below the maximum residue level of 0.02 mg/kg set by the European Union. However, no residues were detected in the tea brew. Regression lines drawn for bifenazate showed that it followed first order dissipation kinetics. Half-life values varied from 1.03 to 1.36 days for bifenazate and a pre-harvest interval of 16 days is suggested.

Momento óptimo de plantación y de cosecha en Tagetes lucida Cav / Optimal time for cultivation and harvesting of Tagetes lucida Cav

Introducción: es necesario establecer guías de cultivo de Tagetes lucida Cav y disponer resultados sobre el momento óptimo de plantación y cosecha en función del rendimiento y del contenido de principios activos. Objetivos: obtener de T lucida mayor cantidad de biomasa y conocer cómo influye la fecha de establecer el cultivo y la hora de realizar la cosecha en la concentración del aceite esencial. Métodos: se hicieron estaquilleros en 2 fechas de 2009 (10 de mayo, 10 de junio), que fueron trasplantados a los 30 d. Se determinó el porcentaje de estacas enraizadas que sobrevivieron al trasplante al lugar definitivo. En el momento de cosecha, realizada con plantas en floración completa, se calculó la altura de las plantas y el rendimiento fresco de las partes aéreas. Se evaluó del total cosechado: porcentajes de flores, ramas y tallos lignificados. Se hicieron recolecciones en una plantación en estado de floración a: 9:00 am, 27 ºC; 12:00 m, 32 ºC y 3:00 pm, 29 ºC. El contenido de aceite esencial se determinó por hidrodestilación durante 2 h. La identificación de componentes se realizó por cromatografía en capa delgada, utilizando como referencias: eugenol, linalol y mirceno (0,3 por ciento). Resultados: en ambas fechas de plantación hubo buena adaptación en el campo, 95 por ciento; se cosechó a 6 meses de edad en la plantación de mayo y a 5 meses de edad en la de junio. Se encontró que entre ellas hubo pocas diferencias en cuanto a altura, rendimiento total de la parte aérea, porcentajes de ramas, flores y tallos, y aceite esencial. Se comprobó que la hora de cosecha realizada en la mañana, produjo la mayor acumulación de aceite esencial (1,20 por ciento) en comparación con las otras horas que fue de 0,75 por ciento...(AU)

Introduction: it is necessary to set the guidelines for cultivation of Tagetes lucida Cav and to obtain results about the optimal time of cultivation and harvesting according to the output and the contents of active principles. Objectives: to get as much quantity of biomass from T Lucida as possible and to find out how the date of cultivation and the time of harvesting influence the concentration of the essential oil. Methods: stake-farming beddings were built on two different dates (10 of May and 10 of June, 2009); they were then transplanted after 30 days. The percentage of rooted stakes that survived after transplantation to the final place was calculated. At the time of harvesting of fully flourished plants, the height of plants and the fresh output of the aerial parts were determined. The total harvested amount was evaluated, that is, percentage of flowers, branches and stems. Harvesting occurred in one flourished plantation at: 9:00 am at 27 °C, at noon at 32 ºC and at 3:00 pm at 29 ºC. Hydrodistillation for 2 h allowed estimating the contents of the essential oil. Thin-layer chromatography identified components using eugenol, linalool and mircene (0.3 percent) as reference. Results: on both dates of cultivation, there was good adaptation to the soils, 95 percent. The plants were harvested at 6 months of age in May and at 5 months in June. There were slight differences in terms of height, total output of the aerial parts, percentages of branches, flowers and stems, and the essential oil. It was confirmed that harvesting in the morning accounted for the highest accumulation of essential oil (1.20 percent) compared with the other harvesting times (0.75 percent)...(AU)

Momento óptimo de plantación y de cosecha en Tagetes lucida Cav / Optimal time for cultivation and harvesting of Tagetes lucida Cav

Introducción: es necesario establecer guías de cultivo de Tagetes lucida Cav y disponer resultados sobre el momento óptimo de plantación y cosecha en función del rendimiento y del contenido de principios activos. Objetivos: obtener de T lucida mayor cantidad de biomasa y conocer cómo influye la fecha de establecer el cultivo y la hora de realizar la cosecha en la concentración del aceite esencial. Métodos: se hicieron estaquilleros en 2 fechas de 2009 (10 de mayo, 10 de junio), que fueron trasplantados a los 30 d. Se determinó el porcentaje de estacas enraizadas que sobrevivieron al trasplante al lugar definitivo. En el momento de cosecha, realizada con plantas en floración completa, se calculó la altura de las plantas y el rendimiento fresco de las partes aéreas. Se evaluó del total cosechado: porcentajes de flores, ramas y tallos lignificados. Se hicieron recolecciones en una plantación en estado de floración a: 9:00 am, 27 ºC; 12:00 m, 32 ºC y 3:00 pm, 29 ºC. El contenido de aceite esencial se determinó por hidrodestilación durante 2 h. La identificación de componentes se realizó por cromatografía en capa delgada, utilizando como referencias: eugenol, linalol y mirceno (0,3 por ciento). Resultados: en ambas fechas de plantación hubo buena adaptación en el campo, 95 por ciento; se cosechó a 6 meses de edad en la plantación de mayo y a 5 meses de edad en la de junio. Se encontró que entre ellas hubo pocas diferencias en cuanto a altura, rendimiento total de la parte aérea, porcentajes de ramas, flores y tallos, y aceite esencial. Se comprobó que la hora de cosecha realizada en la mañana, produjo la mayor acumulación de aceite esencial (1,20 por ciento) en comparación con las otras horas que fue de 0,75 por ciento...

Introduction: it is necessary to set the guidelines for cultivation of Tagetes lucida Cav and to obtain results about the optimal time of cultivation and harvesting according to the output and the contents of active principles. Objectives: to get as much quantity of biomass from T Lucida as possible and to find out how the date of cultivation and the time of harvesting influence the concentration of the essential oil. Methods: stake-farming beddings were built on two different dates (10 of May and 10 of June, 2009); they were then transplanted after 30 days. The percentage of rooted stakes that survived after transplantation to the final place was calculated. At the time of harvesting of fully flourished plants, the height of plants and the fresh output of the aerial parts were determined. The total harvested amount was evaluated, that is, percentage of flowers, branches and stems. Harvesting occurred in one flourished plantation at: 9:00 am at 27 °C, at noon at 32 ºC and at 3:00 pm at 29 ºC. Hydrodistillation for 2 h allowed estimating the contents of the essential oil. Thin-layer chromatography identified components using eugenol, linalool and mircene (0.3 percent) as reference. Results: on both dates of cultivation, there was good adaptation to the soils, 95 percent. The plants were harvested at 6 months of age in May and at 5 months in June. There were slight differences in terms of height, total output of the aerial parts, percentages of branches, flowers and stems, and the essential oil. It was confirmed that harvesting in the morning accounted for the highest accumulation of essential oil (1.20 percent) compared with the other harvesting times (0.75 percent)...

Modelling Common Agricultural Policy-Water Framework Directive interactions and cost-effectiveness of measures to reduce nitrogen pollution.

Selecting cost-effective measures to regulate agricultural water pollution to conform to the Water Framework Directive presents multiple challenges. A bio-economic modelling approach is presented that has been used to explore the water quality and economic effects of the 2003 Common Agricultural Policy Reform and to assess the cost-effectiveness of input quotas and emission standards against nitrate leaching, in a representative case study catchment in Scotland. The approach combines a biophysical model (NDICEA) with a mathematical programming model (FSSIM-MP). The results indicate only small changes due to the Reform, with the main changes in farmers' decision making and the associated economic and water quality indicators depending on crop price changes, and suggest the use of target fertilisation in relation to crop and soil requirements, as opposed to measures targeting farm total or average nitrogen use.

Nutritional quality of organic foods: a systematic review.

BACKGROUND: Despite growing consumer demand for organically produced foods, information based on a systematic review of their nutritional quality is lacking. OBJECTIVE: We sought to quantitatively assess the differences in reported nutrient content between organically and conventionally produced foodstuffs. DESIGN: We systematically searched PubMed, Web of Science, and CAB Abstracts for a period of 50 y from 1 January 1958 to 29 February 2008, contacted subject experts, and hand-searched bibliographies. We included peer-reviewed articles with English abstracts in the analysis if they reported nutrient content comparisons between organic and conventional foodstuffs. Two reviewers extracted study characteristics, quality, and data. The analyses were restricted to the most commonly reported nutrients. RESULTS: From a total of 52,471 articles, we identified 162 studies (137 crops and 25 livestock products); 55 were of satisfactory quality. In an analysis that included only satisfactory-quality studies, conventionally produced crops had a significantly higher content of nitrogen, and organically produced crops had a significantly higher content of phosphorus and higher titratable acidity. No evidence of a difference was detected for the remaining 8 of 11 crop nutrient categories analyzed. Analysis of the more limited database on livestock products found no evidence of a difference in nutrient content between organically and conventionally produced livestock products. CONCLUSIONS: On the basis of a systematic review of studies of satisfactory quality, there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs. The small differences in nutrient content detected are biologically plausible and mostly relate to differences in production methods.

Nutrient biofortification of food crops.

Plant-based foods offer an array of nutrients that are essential for human nutrition and promote good health. However, the major staple crops of the world are often deficient in some of these nutrients. Traditional agricultural approaches can marginally enhance the nutritional value of some foods, but the advances in molecular biology are rapidly being exploited to engineer crops with enhanced key nutrients. Nutritional targets include elevated mineral content, improved fatty acid composition, increased amino acid levels, and heightened antioxidant levels. Unfortunately, in many cases the benefits of these "biofortified" crops to human nutrition have not been demonstrated.

Elevating optimal human nutrition to a central goal of plant breeding and production of plant-based foods.

High-yielding cereals and other staples have produced adequate calories to ward off starvation for much of the world over several decades. However, deficiencies in certain amino acids, minerals, vitamins and fatty acids in staple crops, and animal diets derived from them, have aggravated the problem of malnutrition and the increasing incidence of certain chronic diseases in nominally well-nourished people (the so-called diseases of civilization). Enhanced global nutrition has great potential to reduce acute and chronic disease, the need for health care, the cost of health care, and to increase educational attainment, economic productivity and the quality of life. However, nutrition is currently not an important driver of most plant breeding efforts, and there are only a few well-known efforts to breed crops that are adapted to the needs of optimal human nutrition. Technological tools are available to greatly enhance the nutritional value of our staple crops. However, enhanced nutrition in major crops might only be achieved if nutritional traits are introduced in tandem with important agronomic yield drivers, such as resistance to emerging pests or diseases, to drought and salinity, to herbicides, parasitic plants, frost or heat. In this way we might circumvent a natural tendency for high yield and low production cost to effectively select against the best human nutrition. Here we discuss the need and means for agriculture, food processing, food transport, sociology, nutrition and medicine to be integrated into new approaches to food production with optimal human nutrition as a principle goal.

Genetically Engineered Plants and Foods: A Scientist's Analysis of the Issues (Part I).

Through the use of the new tools of genetic engineering, genes can be introduced into the same plant or animal species or into plants or animals that are not sexually compatible-the latter is a distinction with classical breeding. This technology has led to the commercial production of genetically engineered (GE) crops on approximately 250 million acres worldwide. These crops generally are herbicide and pest tolerant, but other GE crops in the pipeline focus on other traits. For some farmers and consumers, planting and eating foods from these crops are acceptable; for others they raise issues related to safety of the foods and the environment. In Part I of this review some general and food issues raised regarding GE crops and foods will be addressed. Responses to these issues, where possible, cite peer-reviewed scientific literature. In Part II to appear in 2009, issues related to environmental and socioeconomic aspects of GE crops and foods will be covered.

Levels of organochlorine pesticides in crops and related products from Vojvodina, Serbia: estimated dietary intake.

Levels of 16 organochlorine pesticides (OCPs) were investigated in 39 composite samples of agricultural crops, related by-products, and foodstuffs collected in Vojvodina, Serbia, in 2002 through 2004. After extraction and cleanup, OCPs were determined by capillary gas chromatography using electron-capture detection. The highest mean level of 0.971 ng/g whole weight (ww) was found for alpha-HCH in wheat flour samples. OCPs levels were well lower than the respective maximum residue limits set by current European and Serbian regulations. Mean OCP levels were low (<1 ng/g ww) for all sample types. The most frequently determined residue was 4,4'-DDT (identified in 76.9% of all samples analyzed), followed by gamma-HCH (66.7%), beta-HCH (48.7%), and endosulfan II (41.0%). OCP levels were compared with data from other international surveys. Calculated daily intakes of OCPs by way of consumption of the crop products included in this study according to data of the Serbian National Institute for Statistics were compared with the acceptable daily intakes established by the Food and Agriculture Organization/World Health Organization. The average level of contamination of the Vojvodina diet was believed to be harmless regarding the studied food commodities.

Ensuring the supply of and creating demand for a biofortified crop with a visible trait: lessons learned from the introduction of orange-fleshed sweet potato in drought-prone areas of Mozambique.

BACKGROUND: Orange-fleshed sweet potato (OFSP) is a promising biofortified crop for sub-Saharan Africa because it has high levels of provitamin A carotenoids, the formed vitamin A is bioavailable, and white-fleshed sweet potato is already widely grown. OBJECTIVES: To examine whether farmers will adopt varieties with a distinct visible trait, young children will eat OFSP in sufficient quantities to improve vitamin A intake, OFSP can serve as an entry point for promoting a more diversified diet, and lessons can be drawn to assure sustained adoption. METHODS: The 2-year quasi-experimental intervention study followed households and children (n = 741; mean age, 13 months at baseline) through two agricultural cycles in drought prone-areas of Mozambique. RESULTS: OFSP is acceptable to farmers when introduced by using an integrated approach. In the second year, intervention children (n = 498) were more likely than control children (n = 243) to have consumed OFSP (54% vs. 4%), dark-green leaves (60% vs. 46%), or ripe papaya (65% vs. 42%) on 3 or more days in the previous week (p < .001 for all comparisons). Their vitamin A intakes were nearly eight times higher than those of control children (median, 426 vs. 56 1g RAE [retinol activity equivalents], p < .001). Diet diversification was limited by difficult agroecological conditions and low purchasing power. However, dietary diversity was higher among intervention than control children (32% vs. 9% consuming food from more than four groups; p < .001). CONCLUSIONS: An integrated OFSP-based approach had a positive impact on the vitamin A intake of young children. A market development component and improved vine multiplication systems are recommended to assure sustained adoption.

Evaluating yield quality and quantity of garlic as affected by different farming systems and garlic clones.

In order to study the effects of different farming systems and garlic (Allium sativum L.) clones on yield quality and quantity of garlic, an experiment was conducted with split plot arrangement with three completely randomized blockes in the 2005 growing season at the experimental research station of Shahid Beheshti University at Zirab, north of Iran. Two factors were involved in the experiment: farming systems in three levels (intensive, conventional and organic farming), as main plots and garlic clones in three levels (Atoo, Hamedani and Khorassani) as sub-plots. The studied factors in this experiment consisted of leaf number, LAI, stem height and diameter, bulb yield, weight of bulbs, number of cloves, weight of cloves and level of allicin. Results showed that the farming systems had significant effect (p<0.05) on LAI, number of plant and bulb yield, but the effect on the other factors was not significant. The highest and lowest bulb yields were obtained in intensive (9.5 ton ha(-1)) and organic (7.4 ton ha(-1)) systems, respectively. All of the top factors were significantly (p< or =0.01) affected by garlic clones. Maximum and minimum yields were obtained from Hamedani, Atoo (9.2 ton ha(-1)) and Virani (7.1 ton ha(-1)) clones, respectively. Level of allicin was not significantly affected by farming systems but, differences among garlic clones were significant. Maximum and minimum allicin yields were obtained from Hamedan (5.96 mg g(-1)) and Virani (4.52 mg g(-1)) clones, respectively. As a result, however, organic farming systems can not influence the yield in short term, but can increase it by applying crop rotation, use of organic fertilizer and cover crops in the long term.

Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers.

Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to study the effects of compound fertilizers on their yields and quality. In the citrus experiment, application of compound fertilizers increased available P, K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51, 0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea. Optimal rates of compound fertilizers were recommended for both crops.

Employing a composite gene-flow index to numerically quantify a crop's potential for gene flow: an Irish perspective.

Guidelines to ensure the efficient coexistence of genetically modified (GM) and conventional crops are currently being considered across the European Union. The purpose of this strategy is to describe the measures a farmer must adopt to minimize the admixture of GM and non-GM crops. Minimizing pollen/seed-mediated gene flow between GM and non-GM crops is central to successful coexistence. However no system is currently available to permit the numeric quantification of a crop's propensity for pollen/seed-mediated gene flow. The provision of such a system could permit a background level of gene flow, specific for a particular conventional crop, to be calculated. Here we present a gene flow index model implemented using the principal arable crops in Ireland as a model dataset. The objective of this research was to establish a baseline gene flow data set for Ireland's primary conventional crops through the provision of a simple numerical index. This Gene Flow Index (GFI) incorporates four strands of crop-mediated gene flow (crop pollen-to-crop, crop pollen-to-wild, crop seed-to-volunteer and crop seed-to-feral) into a format that permits the calculation of a crop's gene flow potential. Responsive to regional parameters, we have applied the model to sugar beet, oilseed rape, potato, ryegrass, maize, wheat and barley. We propose that the attained indices will highlight those crops that require additional measures in order to minimize gene flow in accordance with anticipated coexistence guidelines.

Micronutrient fortification of plants through plant breeding: can it improve nutrition in man at low cost?

Can commonly-eaten food staple crops be developed that fortify their seeds with essential minerals and vitamins? Can farmers be induced to grow such varieties? If so, would this result in a marked improvement in human nutrition at a lower cost than existing nutrition interventions? An interdisciplinary international effort is underway to breed for mineral- and vitamin-dense varieties of rice, wheat, maize, beans and cassava for release to farmers in developing countries. The biofortification strategy seeks to take advantage of the consistent daily consumption of large amounts of food staples by all family members, including women and children as they are most at risk for micronutrient malnutrition. As a consequence of the predominance of food staples in the diets of the poor, this strategy implicitly targets low-income households. After the one-time investment is made to develop seeds that fortify themselves, recurrent costs are low and germplasm may be shared internationally. It is this multiplier aspect of plant breeding across time and distance that makes it so cost-effective. Once in place, the biofortified crop system is highly sustainable. Nutritionally-improved varieties will continue to be grown and consumed year after year, even if government attention and international funding for micronutrient issues fades. Biofortification provides a truly feasible means of reaching malnourished populations in relatively remote rural areas, delivering naturally-fortified foods to population groups with limited access to commercially-marketed fortified foods that are more readily available in urban areas. Biofortification and commercial fortification are, therefore, highly complementary. Breeding for higher trace mineral density in seeds will not incur a yield penalty. Mineral-packed seeds sell themselves to farmers because, as recent research has shown, these trace minerals are essential in helping plants resist disease and other environmental stresses. More seedlings survive and initial growth is more rapid. Ultimately, yields are higher, particularly in trace mineral-'deficient' soils in arid regions.

Genetic integrity of ex situ Genebank collections.

The genetic integrity of four accessions of the cross-pollinating species rye (Secale cereale L.) was investigated. Seeds available from the first and most recent regeneration cycles, multiplied 8, 12 (twice) or 14 times were fingerprinted using microsatellite markers. In all four accessions the allele numbers and frequencies changed after regeneration. Alleles present in the original seed sample were not detectable in the regenerated populations, whereas on the other hand, alleles were found in the recent seed sample, which were not observed in the investigated plants of the original one.