Agriculture

9 pages, 1740 KiB

Open AccessFeature PaperArticle

Involvement of Epigenetic Mechanisms in Herbicide Resistance: The Case of Conyza canadensis

by Theoni Margaritopoulou, Eleni Tani, Demosthenis Chachalis and Ilias Travlos

Agriculture 2018, 8(1), 17; https://doi.org/10.3390/agriculture8010017 - 22 Jan 2018

Cited by 20 | Viewed by 6143

Glyphosate is the most important herbicide globally, and horseweed (Conyza canadensis) has been one of the most commonly encountered weed species that has developed resistance to it in various parts of the world, including Greece. After glyphosate application, horseweed populations show [...] Read more.

Glyphosate is the most important herbicide globally, and horseweed (Conyza canadensis) has been one of the most commonly encountered weed species that has developed resistance to it in various parts of the world, including Greece. After glyphosate application, horseweed populations show a wide range of phenotypic plasticity in response to selection pressure. In previous work, we have proposed a herbicide resistance mechanism that is not due to a point mutation at the codon 106 of EPSP synthase but most likely due to a synchronized overexpression of EPSPS and the ABC transporter genes. In the current study, it is hypothesized that the observed phenotypic alterations and differential expression of the EPSPS gene could be attributed to epigenetic changes. DNA methylation plays a pivotal role in many biological procedures such as gene expression, differentiation, and cellular proliferation. Sodium bisulfite sequencing was used to detect epigenetic changes that occur at the C5 position of cytosine residues within CpGdi nucleotides in two horseweed populations (resistant vs. susceptible). Results show differential methylation pattern between the two populations. This work will elucidate the naturally increased resistance of C. Canadensis to glyphosate and set the bases for future development of techniques that restrict weed resistance to herbicides. Full article

(This article belongs to the Special Issue Weed Management)

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11 pages, 622 KiB

Open AccessArticle

Farmers’ Knowledge on Pesticide Safety and Pest Management Practices: A Case Study of Vegetable Growers in Chitwan, Nepal

by Jhalendra P. Rijal, Rajendra Regmi, Rajan Ghimire, Krishna D. Puri, Sudan Gyawaly and Sujata Poudel

Agriculture 2018, 8(1), 16; https://doi.org/10.3390/agriculture8010016 - 22 Jan 2018

Cited by 45 | Viewed by 18045

Abstract

Farmers’ knowledge on pesticides and their safe use are critical for implementing effective pest management program. A household survey was conducted using the semi-structured questionnaire to evaluate vegetable growers’ knowledge on pesticide safety and pest management practices in Nepal. Results indicated that chemical [...] Read more.

Farmers’ knowledge on pesticides and their safe use are critical for implementing effective pest management program. A household survey was conducted using the semi-structured questionnaire to evaluate vegetable growers’ knowledge on pesticide safety and pest management practices in Nepal. Results indicated that chemical pesticides were the primary choice of over 80% growers for pest management. Notably, 90% growers were aware of adverse effects of pesticides on human health and to the environment. Over 84% growers used at least one form of personal protection equipment (PPE) during pesticide spray or handling, although the quality and appropriateness of the PPE warrants further investigation. Nearly 17% growers received at least one short-term training on integrated pest management (IPM); however, all of them neither knew the harmful effects of pesticide residues nor practiced proper pesticide disposal methods. Over 90% of growers rely on local pesticide retailers (i.e., Agro-vets) for technical know-how about pesticide selection, handling, and use. This study highlighted a need for immediate implementation of strict pesticide use regulations and recommended educational programs for pest control professionals, growers, and pesticide retailers. Full article

(This article belongs to the Special Issue Pesticides in Agriculture System)

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4 pages, 324 KiB

Open AccessEditorial

Acknowledgement to Reviewers of Agriculture in 2017

by Agriculture Editorial Office

Agriculture 2018, 8(1), 15; https://doi.org/10.3390/agriculture8010015 - 22 Jan 2018

Viewed by 4425

Abstract

Peer review is an essential part in the publication process, ensuring that Agriculture maintains high quality standards for its published papers.[...] Full article

17 pages, 1077 KiB

Open AccessReview

Macro and Micronutrient Storage in Plants and Their Remobilization When Facing Scarcity: The Case of Drought

by Philippe Etienne, Sylvain Diquelou, Marion Prudent, Christophe Salon, Anne Maillard and Alain Ourry

Agriculture 2018, 8(1), 14; https://doi.org/10.3390/agriculture8010014 - 16 Jan 2018

Cited by 92 | Viewed by 12944

Abstract

Human mineral malnutrition or hidden hunger is considered a global challenge, affecting a large proportion of the world’s population. The reduction in the mineral content of edible plant products is frequently found in cultivars bred for higher yields, and is probably increased by [...] Read more.

Human mineral malnutrition or hidden hunger is considered a global challenge, affecting a large proportion of the world’s population. The reduction in the mineral content of edible plant products is frequently found in cultivars bred for higher yields, and is probably increased by intensive agricultural practices. The filling of grain with macro and micronutrients is partly the result of a direct allocation from root uptake and remobilization from vegetative tissues. The aim of this bibliographic review is to focus on recent knowledge obtained from ionomic analysis of plant tissues in order to build a global appraisal of the potential remobilization of all macro and micronutrients, and especially those from leaves. Nitrogen is always remobilized from leaves of all plant species, although with different efficiencies, while nutrients such as K, S, P, Mg, Cu, Mo, Fe and Zn can be mobilized to a certain extent when plants are facing deficiencies. On the opposite, there is few evidence for leaf mobilization of Ca, Mn, Ni and B. Mechanisms related to the remobilization process (remobilization of mineral forms from vacuolar and organic compounds associated with senescence, respectively) are also discussed in the context of drought, an abiotic stress that is thought to increase and known to modulate the ionic composition of grain in crops. Full article

(This article belongs to the Special Issue Plant Nutrient Dynamics in Stressful Environments)

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6 pages, 209 KiB

Open AccessEditorial

Current Status and Recent Developments in Biopesticide Use

by Christos A. Damalas and Spyridon D. Koutroubas

Agriculture 2018, 8(1), 13; https://doi.org/10.3390/agriculture8010013 - 12 Jan 2018

Cited by 250 | Viewed by 25269

Abstract

Biopesticides have attracted attention in pest management in recent decades, and have long been promoted as prospective alternatives to synthetic pesticides. Biopesticides have also attracted great interest in the international research community, with a significant increase in the number of publications devoted to [...] Read more.

Biopesticides have attracted attention in pest management in recent decades, and have long been promoted as prospective alternatives to synthetic pesticides. Biopesticides have also attracted great interest in the international research community, with a significant increase in the number of publications devoted to the subject. Recently, new substances, like strains of the fungus Talaromyces flavus SAY-Y-94-01, extracts of the plant Clitoria ternatea (butterfly pea), products of the fungus Trichoderma harzianum, products of the bacterium Bacillus thuringiensis var. tenebrionis strain Xd3 (Btt-Xd3), the alkaloid compound oxymatrine, fermentation products of the bacterium Lactobacillus casei strain LPT-111, stilbenes accumulated in grape canes, and olive mill wastes, have been reported in the literature as promising compounds for use as biopesticides, but more field research is required to assess the effects on specific pest problems under diverse cropping systems. Nevertheless, biopesticides have not yet reached the desired level of use, whereby they could displace the dominance of chemical pesticides, given that the commercialization of new products in the market is lagging behind. Currently, biopesticides comprise a small share of the total crop protection market globally, with a value of about $3 billion worldwide, accounting for just 5% of the total crop protection market. Fewer biopesticide-active substances are registered in the European Union (EU) than in the United States, India, Brazil, or China, due to long and complex registration processes in the EU, which follow the model for the registration of conventional pesticides. Nanoformulations and microencapsulation technologies can improve the stability and residual action of biopesticide products, and this could increase their field use. Regulations that promote registration of low-risk compounds with the provision of incentives could also facilitate commercialization and availability of biopesticides in the market. Full article

(This article belongs to the Special Issue Pesticides in Agriculture System)

15 pages, 267 KiB

Open AccessArticle

Agroecological, Land-Elevation and Socioeconomic Determinants of Raising Livestock in Bangladesh

by Sanzidur Rahman

Agriculture 2018, 8(1), 12; https://doi.org/10.3390/agriculture8010012 - 11 Jan 2018

Cited by 4 | Viewed by 4317

Abstract

This paper determines the influence of agroecological, land-elevation and socioeconomic factors in the raising of different types of livestock in Bangladesh using nationwide sub-district level data from two Agriculture and Livestock Censuses of 1996 and 2008, by applying a simultaneous equations model. Results [...] Read more.

This paper determines the influence of agroecological, land-elevation and socioeconomic factors in the raising of different types of livestock in Bangladesh using nationwide sub-district level data from two Agriculture and Livestock Censuses of 1996 and 2008, by applying a simultaneous equations model. Results reveal that socioeconomic, land-elevation and agroecological factors exert significant but varied influence on the type of livestock raised by householders. The number of cattle, goat/sheep and poultry raised per household are significantly higher for medium and small farms as well as for wage-labour households. Cattle raised per household is significantly higher for non-farm households, whereas poultry raised is significantly lower. Gross-cropped area, literacy rate and research and development (R&D) investment significantly influence the number of cattle raised per household, whereas population density negatively influences the number of goat and poultry raised per household. The number of cattle and goat/sheep raised per household is significantly higher in the Old Himalayan Floodplain, whereas poultry-raising is significantly higher in the Eastern Hills and seven other agroecologies. Raising all types of livestock is significantly lower in low-lying areas. The number of cattle raised per household is significantly higher at high land elevation, but significantly lower in medium-low land and low-lying areas. On the other hand, the number of goat/sheep and poultry raised per household is significantly higher in medium-high land areas and significantly lower in low-lying areas. The policy implications of these results will be relevant to investments in R&D, education, tenurial reform and measures to promote different types of livestock suited to specific agroecology and land-elevation levels. Full article

14 pages, 1798 KiB

Open AccessArticle

Surfactin Protects Wheat against Zymoseptoria tritici and Activates Both Salicylic Acid- and Jasmonic Acid-Dependent Defense Responses

by Geraldine Le Mire, Ali Siah, Marie-Noëlle Brisset, Matthieu Gaucher, Magali Deleu and M. Haissam Jijakli

Agriculture 2018, 8(1), 11; https://doi.org/10.3390/agriculture8010011 - 9 Jan 2018

Cited by 36 | Viewed by 7248

Abstract

Natural elicitors induce plant resistance against a broad spectrum of diseases, and are currently among the most promising biocontrol tools. The present study focuses on the elicitor properties of the cyclic lipopeptide surfactin on wheat, in order to stimulate the defenses of this [...] Read more.

Natural elicitors induce plant resistance against a broad spectrum of diseases, and are currently among the most promising biocontrol tools. The present study focuses on the elicitor properties of the cyclic lipopeptide surfactin on wheat, in order to stimulate the defenses of this major crop against the challenging fungal pathogen Zymoseptoria tritici. The protection efficacy of surfactin extracted from the strain Bacillus amyloliquefaciens S499 was investigated through greenhouse trials. Surfactin protected wheat by 70% against Z. tritici, similarly to the chemical reference elicitor Bion^®50WG. In vitro biocidal assays revealed no antifungal activities of surfactin towards the pathogen. A biomolecular RT-qPCR based low-density microarray tool was used to study the relative expression of 23 wheat defense genes. Surfactin significantly induced wheat natural defenses by stimulating both salicylic acid- and jasmonic acid-dependent signaling pathways. Surfactin was successfully tested as an elicitor on the pathosystem wheat–Z. tritici. These results promote further sustainable agricultural practices and the reduction of chemical inputs. Full article

(This article belongs to the Special Issue Sustainable Crop Production Intensification)

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11 pages, 1755 KiB

Open AccessArticle

Agricultural Health and Safety Survey in Friuli Venezia Giulia

by Sirio Rossano Secondo Cividino, Gianfranco Pergher, Nicola Zucchiatti and Rino Gubiani

Agriculture 2018, 8(1), 9; https://doi.org/10.3390/agriculture8010009 - 8 Jan 2018

Cited by 19 | Viewed by 5360

Abstract

The work in the agricultural sector has taken on a fundamental role in the last decades, due to the still too high rate of fatal injuries, workplace accidents, and dangerous occurrences reported each year. The average old age of agricultural machinery is one [...] Read more.

The work in the agricultural sector has taken on a fundamental role in the last decades, due to the still too high rate of fatal injuries, workplace accidents, and dangerous occurrences reported each year. The average old age of agricultural machinery is one of the main issues at stake in Italy. Numerous safety problems stem from that; therefore, two surveys were conducted in two different periods, on current levels of work safety in agriculture in relation to agricultural machinery’s age and efficiency, and to show the levels of actual implementation of the Italian legislation on safety and health at work in the agricultural sector. The surveys were carried out, considering a sample of 161 farms located in the region Friuli Venezia Giulia (North-East of Italy). The research highlights the most significant difficulties the sample of farms considered have in enforcing the law. One hand, sanitary surveillance and workers’ information and training represent the main deficiencies and weakest points in family farms. Moreover, family farms do not generally provide the proper documentation concerning health and safety at workplaces, when they award the contract to other companies. On the other hand, lack of maintenance program for machinery and equipment, and of emergency plans and participation of workers’ health and safety representative, are the most common issues in farms with employees. Several difficulties are also evident in planning workers’ training programs. Furthermore, the company physician’s task is often limited to medical controls, so that he is not involved in risk assessment and training. Interviews in heterogeneous samples of farms have shown meaningful outcomes, which have subsequently been used to implement new databases and guidelines for Health and Safety Experts and courses in the field of Work Safety in agriculture. In conclusion, although the legislation making training courses for tractor operators and tractor inspections compulsory dates back to the years 2012 and 2015, deadlines have been prorogued, and the law is not yet fully applied, so that non-upgraded unfit old agricultural machinery is still being used by many workers, putting their health and their own lives at risk. Full article

(This article belongs to the Special Issue Smart machines, Remote Sensing, Precision Farming, Processes, Mechatronic, Materials and Policies for Safety and Health Aspects)

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14 pages, 252 KiB

Open AccessArticle

Measuring the Economic Impact of Farmers’ Markets on Local Economies in the Basque Country

by Eduardo Malagon-Zaldua, Mirene Begiristain-Zubillaga and Aintzira Onederra-Aramendi

Agriculture 2018, 8(1), 10; https://doi.org/10.3390/agriculture8010010 - 8 Jan 2018

Cited by 23 | Viewed by 6012

Abstract

Farmers’ markets are a traditional exchange space for local peasants, around which alternative agri-food networks (AFNs) are being built on a local scale. These AFNs seek to establish quality and trust-based equitable relationships within value chains. The main objective of this paper is [...] Read more.

Farmers’ markets are a traditional exchange space for local peasants, around which alternative agri-food networks (AFNs) are being built on a local scale. These AFNs seek to establish quality and trust-based equitable relationships within value chains. The main objective of this paper is to measure the economic impact of 10 farmers’ markets on the local economy in the Basque province of Gipuzkoa (Northern Spain). To calculate the degree of impact, we use the tools of input-output analysis, adapting the SEED & NEED & FEED (Sticky Economic Evaluation Device & Neighborhood Exchange Evaluation Device & Food Environment Evaluation Device) approach to the specific context of the Basque Country. The results obtained give an economic value of the impact of these marketing spaces, including direct and indirect effects on other economic sectors. Furthermore, the results show that markets present other factors, not just economic, that add value for both producers and consumers, as well as for the local economy. Full article

(This article belongs to the Special Issue Localized Agrifood Systems: Governance, Market, and Environmental Issues)

24 pages, 309 KiB

Open AccessReview

Sustainable Agriculture—Enhancing Environmental Benefits, Food Nutritional Quality and Building Crop Resilience to Abiotic and Biotic Stresses

by Daniel P. Roberts and Autar K. Mattoo

Agriculture 2018, 8(1), 8; https://doi.org/10.3390/agriculture8010008 - 1 Jan 2018

Cited by 78 | Viewed by 14032

Abstract

Feeding nutrition-dense food to future world populations presents agriculture with enormous challenges as estimates indicate that crop production must as much as double. Crop production cannot be increased to meet this challenge simply by increasing land acreage or using past agricultural intensification methods. [...] Read more.

Feeding nutrition-dense food to future world populations presents agriculture with enormous challenges as estimates indicate that crop production must as much as double. Crop production cannot be increased to meet this challenge simply by increasing land acreage or using past agricultural intensification methods. Food production doubled in the past through substantial use of synthetic fertilizer, pesticides, and irrigation, all at significant environmental cost. Future production of nutrition-dense food will require next-generation crop production systems with decreased reliance on synthetic fertilizer and pesticide. Here, we present three case studies detailing the development of cover crops and plant-beneficial microbes for sustainable, next-generation small grain, tomato, and oilseed rape production systems. Cover crops imparted weed and pathogen control and decreased soil erosion and loss of soil nitrogen, phosphorus and carbon, while plant-beneficial microbes provided disease control and phosphorus fertility. However, yield in these next-generation crop production systems at best approximated that associated with current production systems. We argue here that to substantially increase agricultural productivity, new crop germplasm needs to be developed with enhanced nutritional content and enhanced tolerance to abiotic and biotic stress. This will require using all available technologies, including intensified genetic engineering tools, in the next-generation cropping systems. Full article

(This article belongs to the Special Issue Plant Nutrient Dynamics in Stressful Environments)

10 pages, 1027 KiB

Open AccessArticle

Definition of a Methodology for Gradual and Sustainable Safety Improvements on Farms and Its Preliminary Applications

by Sirio Rossano Secondo Cividino, Gianfranco Pergher, Rino Gubiani, Carlo Moreschi, Ugo Da Broi, Michela Vello and Fabiano Rinaldi

Agriculture 2018, 8(1), 7; https://doi.org/10.3390/agriculture8010007 - 1 Jan 2018

Cited by 11 | Viewed by 4777

Abstract

In many productive sectors, ensuring a safe working environment is still an underestimated problem, and especially so in farming. A lack of attention to safety and poor risk awareness by operators represents a crucial problem, which results in numerous serious injuries and fatal [...] Read more.

In many productive sectors, ensuring a safe working environment is still an underestimated problem, and especially so in farming. A lack of attention to safety and poor risk awareness by operators represents a crucial problem, which results in numerous serious injuries and fatal accidents. The Demetra project, involving the collaboration of the Regional Directorate of INAIL (National Institute for Insurance against Accidents at Work), aims to devise operational solutions to evaluate the risk of accidents in agricultural work and analyze the dynamics of occupational accidents by using an observational method to help farmers ensure optimal safety levels. The challenge of the project is to support farmers with tools designed to encourage good safety management in the agricultural workplaces. Full article

(This article belongs to the Special Issue Smart machines, Remote Sensing, Precision Farming, Processes, Mechatronic, Materials and Policies for Safety and Health Aspects)

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12 pages, 208 KiB

Open AccessArticle

Foods and Places: Comparing Different Supply Chains

by Anna Carbone

Agriculture 2018, 8(1), 6; https://doi.org/10.3390/agriculture8010006 - 1 Jan 2018

Cited by 24 | Viewed by 5548

Abstract

This paper explores the relationships between food and places and how these affect the organization and functioning of different supply chains. The theme is increasingly relevant due to demand trends and new production patterns, including globalization, that deeply affect the (re)localization of production. [...] Read more.

This paper explores the relationships between food and places and how these affect the organization and functioning of different supply chains. The theme is increasingly relevant due to demand trends and new production patterns, including globalization, that deeply affect the (re)localization of production. This is a conceptual paper extensively relying on previous studies done by the author and on evidence and concepts discussed in the literature; it does not present new in-depth case studies or any other original evidences. First, the different ways of conceptualizing and thinking the linkages between food and production places are discussed. Then, three chains that seek at delivering products for which the place of origin is important are compared: (i) short chains, where producers integrate the whole process in order to access the final consumer; (ii) geographical indications, where producers gather under a common name in order to build their reputation in connection with the place of production; (iii) retailers specialized in high quality foods, where advantages of large retailers are combined with the strong identity of products. The objective is to contribute understanding differences in the coordination modes and in the kind of governance at stake in each chain and to compare their strengths and drawbacks in terms of capacity to assure place-related quality and of delivering reliable information to consumers. Attention is also given to the role of farmers within the different chains, as these are usually strongly rooted in the place of origin but the weakest knots in the chain in terms of bargaining power. Vertical and horizontal coordination, together with collective actions, are essential for an effective alignment of the production process that can enhance quality and create/distribute value. The discussion also assesses difficulties and drawbacks related to sharing decisions and to managing common resources. Full article

(This article belongs to the Special Issue Localized Agrifood Systems: Governance, Market, and Environmental Issues)

11 pages, 2541 KiB

Open AccessArticle

Modelling the Collection and Delivery of Sheep Milk: A Tool to Optimise the Logistics Costs of Cheese Factories

by Maria Caria, Giuseppe Todde and Antonio Pazzona

Agriculture 2018, 8(1), 5; https://doi.org/10.3390/agriculture8010005 - 1 Jan 2018

Cited by 11 | Viewed by 5172

Abstract

The milk transformation process, in the last thirty years, moved from on-farm to centralised cheese factories, affecting the management of transport logistics. In Sardinia, the presence of about 12,000 dairy sheep farms, located in rural areas with poor condition of road network, makes [...] Read more.

The milk transformation process, in the last thirty years, moved from on-farm to centralised cheese factories, affecting the management of transport logistics. In Sardinia, the presence of about 12,000 dairy sheep farms, located in rural areas with poor condition of road network, makes collecting milk a significant impact on profit, affecting the costs of milk transportation. Moreover, dairy sheep farming is characterized by seasonal production, this means that the amount of milk that is produced by each farm differs significantly over the year. The objective of this work was to develop a decision support tool that, while optimising milk collection routes, reduced the costs of milk transport, thus improving the density of collection. The tool developed ad hoc in this study used GPS map location and milk volumes of farms to calculate the cost per litre of milk for the regular routing, and to recalculate the same cost for the optimised collecting route. Results showed that this tool improved the efficiency of milk collection, reducing the number of routes and the driving distances. Furthermore, optimising the density of collection, the new routes improved the environmental impact and the transportation costs that are associated with logistic and traceability of raw sheep milk. Full article

(This article belongs to the Special Issue Knowledge and Techniques Application in Agriculture)

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10 pages, 1297 KiB

Open AccessArticle

Photosynthesis of Sago Palm (Metroxylon sagu Rottb.) Seedling at Different Air Temperatures

by Aidil Azhar, Daigo Makihara, Hitoshi Naito and Hiroshi Ehara

Agriculture 2018, 8(1), 4; https://doi.org/10.3390/agriculture8010004 - 1 Jan 2018

Cited by 11 | Viewed by 7350

Abstract

Photosynthetic activities of the sago palm (Metroxylon sagu Rottb.) were studied to find out its sensitivity to changes in ambient air temperature. The minimum ambient air temperature designed for the experiment was 25–29 °C, while the higher end was 29–33 °C. Several [...] Read more.

Photosynthetic activities of the sago palm (Metroxylon sagu Rottb.) were studied to find out its sensitivity to changes in ambient air temperature. The minimum ambient air temperature designed for the experiment was 25–29 °C, while the higher end was 29–33 °C. Several photosynthetic parameters were studied to support our analysis in sago photosynthetic activity, including diurnal leaf gas exchange, assimilation rate vs. CO₂ concentration, leaf greenness, leaf chlorophyll content, and photosynthetic rate vs. irradiance. We found that sago palm photosynthetic activity tends to be more sensitive to minimum than to maximum ambient air temperature. The plants exposed to higher air temperatures had dark green leaf color associated with higher rates of diurnal photosynthesis, chlorophyll content, and rubisco limited photosynthetic activity. They also exhibited higher trend in optimum irradiance absorption level. Consequently, maximum light energy dissipation occurred at higher temperatures. Full article

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17 pages, 2379 KiB

Open AccessArticle

Nitrogen Use Efficiency and the Genetic Variation of Maize Expired Plant Variety Protection Germplasm

by Adriano T. Mastrodomenico, C. Cole Hendrix and Frederick E. Below

Agriculture 2018, 8(1), 3; https://doi.org/10.3390/agriculture8010003 - 1 Jan 2018

Cited by 17 | Viewed by 7412

Abstract

Nitrogen use efficiency (NUE) in maize (Zea mays L.) is an important trait to optimize yield with minimal input of nitrogen (N) fertilizer. Expired Plant Variety Protection (ex-PVP) Act-certified germplasm may be an important genetic resource for public breeding sectors. The objectives [...] Read more.

Nitrogen use efficiency (NUE) in maize (Zea mays L.) is an important trait to optimize yield with minimal input of nitrogen (N) fertilizer. Expired Plant Variety Protection (ex-PVP) Act-certified germplasm may be an important genetic resource for public breeding sectors. The objectives of this research were to evaluate the genetic variation of N-use traits and to characterize maize ex-PVP inbreds that are adapted to the U.S. Corn Belt for NUE performance. Eighty-nine ex-PVP inbreds (36 stiff stalk synthetic (SSS), and 53 non-stiff stalk synthetic (NSSS)) were genotyped using 26,769 single-nucleotide polymorphisms, then 263 single-cross maize hybrids derived from these inbreds were grown in eight environments from 2011 to 2015 at two N fertilizer rates (0 and 252 kg N ha⁻¹) and three replications. Genetic utilization of inherent soil nitrogen and the yield response to N fertilizer were stable across environments and were highly correlated with yield under low and high N conditions, respectively. Cluster analysis identified inbreds with desirable NUE performance. However, only one inbred (PHK56) was ranked in the top 10% for yield under both N-stress and high N conditions. Broad-sense heritability across 12 different N-use traits varied from 0.11 to 0.77, but was not associated with breeding value accuracy. Nitrogen-stress tolerance was negatively correlated with the yield increase from N fertilizer. Full article

(This article belongs to the Special Issue Plant Nutrient Dynamics in Stressful Environments)

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2662 KiB

Open AccessArticle

Using Colony Monitoring Devices to Evaluate the Impacts of Land Use and Nutritional Value of Forage on Honey Bee Health

by Matthew Smart, Clint Otto, Robert Cornman and Deborah Iwanowicz

Agriculture 2018, 8(1), 2; https://doi.org/10.3390/agriculture8010002 - 25 Dec 2017

Cited by 31 | Viewed by 7056

Abstract

Colony monitoring devices used to track and assess the health status of honey bees are becoming more widely available and used by both beekeepers and researchers. These devices monitor parameters relevant to colony health at frequent intervals, often approximating real time. The fine-scale [...] Read more.

Colony monitoring devices used to track and assess the health status of honey bees are becoming more widely available and used by both beekeepers and researchers. These devices monitor parameters relevant to colony health at frequent intervals, often approximating real time. The fine-scale record of hive condition can be further related to static or dynamic features of the landscape, such as weather, climate, colony density, land use, pesticide use, vegetation class, and forage quality. In this study, we fit commercial honey bee colonies in two apiaries with pollen traps and digital scales to monitor floral resource use, pollen quality, and honey production. One apiary was situated in low-intensity agriculture; the other in high-intensity agriculture. Pollen traps were open for 72 h every two weeks while scales recorded weight every 15 min throughout the growing season. From collected pollen, we determined forage quantity per day, species identity using DNA sequencing, pesticide residues, amino acid content, and total protein content. From scales, we determined the accumulated hive weight change over the growing season, relating to honey production and final colony weight going into winter. Hive scales may also be used to identify the occurrence of environmental pollen and nectar dearth, and track phenological changes in plant communities. We provide comparisons of device-derived data between two apiaries over the growing season and discuss the potential for employing apiary monitoring devices to infer colony health in the context of divergent agricultural land use conditions. Full article

(This article belongs to the Special Issue Pollination and Agriculture)

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1134 KiB

Open AccessArticle

Assessment of Mesotrione Leaching Applied Alone and Mixed in Seven Tropical Soils Columns under Laboratory Conditions

by Kassio F. Mendes, Marcelo R. Dos Reis, Kurt A. Spokas and Valdemar L. Tornisielo

Agriculture 2018, 8(1), 1; https://doi.org/10.3390/agriculture8010001 - 21 Dec 2017

Cited by 1 | Viewed by 4495

Abstract

Herbicide leaching is influenced by soil physical and chemical properties as well as the prevailing climatic conditions. However, little is known about leaching of mixture of herbicides in the soil, especially in tropical regions like Brazil. The objective of this study is to [...] Read more.

Herbicide leaching is influenced by soil physical and chemical properties as well as the prevailing climatic conditions. However, little is known about leaching of mixture of herbicides in the soil, especially in tropical regions like Brazil. The objective of this study is to evaluate the leaching of ¹⁴C-mesotrione (cyclohexane-2-¹⁴C-mesotrione) alone and in a mixture with S-metolachlor and terbuthylazine in seven tropical soil columns under laboratory conditions. These soils represented a wide range of properties with varying textures, cation exchange capacity (44 to 154 mmol_c kg⁻¹), pH (6.0 to 7.7), organic carbon content (0.58 to 27.32 g kg⁻¹) and clay mineral contents (50 to 605 g kg⁻¹), which are typical of tropical soils. Mesotrione residues were observed across all soil column layers (0–30 cm) in all evaluated soils by simulating 200 mm of water for 48 h. The application of mesotrione, alone or in a mixture, does not influence the leaching of this herbicide. Leaching of mesotrione ranged from low (up 15 cm) to very high (up 30 cm and leachate) in the tropical soils and may pose a potential groundwater contamination risk. In sand and loamy sand soil, the mesotrione was quantified in the leachate at all sampling times as above 80% of the amount initially applied. Thus, mesotrione application without the prior knowledge of the soil physical and chemical properties can result in inefficient weed control on field condition due to high leaching potentials. Full article

(This article belongs to the Special Issue Weed Management)

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