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Arthropods are essential in maintaining healthy and productive agricultural ecosystems. Agricultural crops such as apples are typically pollinated by domesticated honey bees, but wild bees and other arthropod flower visitors also contribute to pollination. Flower visitors can also be natural enemies of crop-pests or herbivores. Biodiversity is under pressure and knowledge of wildflower visitors is an important tool in designing orchards that can support high functional biodiversity. In our study, we assessed the diversity of arthropod flower visitors in four Danish apple orchards using both molecular and nonmolecular techniques to study arthropod communities in agricultural ecosystems. Arthropod DNA collected from apple flowers was analyzed using a DNA metabarcoding approach using the mitochondrial COI marker, while arthropod pollinators were recorded through visual assessment surveys. These complementary techniques resulted in a total of 19 arthropod taxa detected. Nonbee arthropods constituted a large proportion of arthropods detected by both methods (84%, 16 taxa). Metabarcoding detected 12 taxa and had 83% species resolution. Visual census recovered flower visiting groups to the order level (Coleoptera, Diptera, Hymenoptera and Lepidoptera) but not species level and also provided relative abundance data, which is not possible with molecular methods. We demonstrated that by utilizing both molecular and nonmolecular techniques to assess arthropod communities, we are able to obtain a broader overview of the arthropod fauna present. The methodology used and the outcome of this study can be used to inform and tailor suitable arthropod-pest management practices in orchards to increase crop yield and maintain healthy agricultural systems.

Conflicts arising from the consumption of anthropogenic foods by wildlife are increasing worldwide. Conventional tools for evaluating the spatial distribution pattern of large terrestrial mammals that consume anthropogenic foods have various limitations, despite their importance in management to mitigate conflicts. In this study, we examined the spatial distribution pattern of crop‐foraging sika deer by performing nitrogen stable isotope analyses of bone collagen. We evaluated whether crop‐foraging deer lived closer to agricultural crop fields during the winter and spring, when crop production decreases. We found that female deer in proximity to agricultural crop fields during the winter and spring were more likely to be crop‐foraging individuals. Furthermore, the likelihood of crop consumption by females decreased by half as the distance to agricultural crop fields increased to 5–10 km. We did not detect a significant trend in the spatial distribution of crop‐foraging male deer. The findings of spatial distribution patterns of crop‐foraging female deer will be useful for the establishment of management areas, such as zonation, for efficient removal of them., We examined the spatial distribution pattern of crop‐foraging sika deer by performing nitrogen stable isotope analyses. Female deer in proximity to agricultural crop fields were more likely to be crop‐foraging individuals and the likelihood of crop consumption decreased by half as the distance to agricultural crop fields increased to 5–10 km.

Background The technological advances in agriculture, driven by the increased demand for food attributed to population growth, have led to the search for technologies that allow greater control over the variables that interfere in crop yield. Several techniques stand out for optimizing yield capacity, including cultivation in a protected environment, mulching and low tunneling. To expand the use of these techniques, synthetic petroleum-based polymers are employed due to their low cost, easy processing, and lightness. However, they take a long time to degrade, and, since they are discarded at the end of each cycle of cultivation, end up accumulating in the environment causing irreversible damage. Results The use of biodegradable films, made of starch and/or a protein source such as gelatin, has been studied as a promising alternative. Both stand out because of their film-forming ability, and because they come from abundant sources and are biodegradable. Conclusion This study aimed to review the current findings on starch and gelatin films that can be used as alternatives to conventional plastics in agricultural crops. © 2019 Society of Chemical Industry.

Anthropogenic foods such as agricultural crops have potential to give large impacts on wildlife populations. However, few studies have addressed the impact of anthropogenic food consumption on the individual performance and then population of long‐lived mammals such as large herbivores. In this study, we investigated the effect of agricultural crop consumption on the physical characteristics and reproductive performances of sika deer (Cervus nippon) in central Japan. To investigate the relative dietary contribution of agricultural crops for each individual, we performed nitrogen stable isotope analysis of bone collagen. Our results suggest that nitrogen stable isotope ratios (δ15N) could be used as an index of the relative dietary contribution of agricultural crops. The δ15N value of agricultural crops was much higher than that of wild plants and that of bone collagen varied widely among individuals. Deer ≤4 yr old that were more likely to consume agricultural crops tended to be larger and have a higher reproductive rate. In contrast, body size and reproductive rate did not vary according to the relative dietary contribution of agricultural crops in individuals ≥5 yr old. These results indicate that consumption of anthropogenic foods can induce precocious maturity in younger individuals by improving their physical characteristics and reproductive performance. Agricultural crop consumption is therefore likely to be an important factor in the population dynamics of large herbivores living in agricultural landscapes.

We estimate the short‐ and long‐run global response of corn, soybeans, wheat, and rice growing areas to output price changes allowing responses to vary across countries using methods from the panel time‐series literature. Our estimates of growing‐area response are considerably lower than estimates obtained using more traditional models. Previous findings appear biased due to the assumption of homogeneous response across countries. Our aggregate estimates of short‐ and long‐run elasticities of four crop growing areas with respect to average price are 0.024 and 0.143, respectively. Crop‐specific results indicate that both corn and soybean growing areas are generally more responsive than wheat and rice. For corn and soybeans, the long‐run own‐price growing‐area elasticities are 0.274 and 0.793, respectively. The long‐run own‐price elasticities for wheat and rice are 0.279 and 0.045, respectively. The short‐run own‐price elasticities for corn and soybeans are 0.133 and 0.199, respectively, which are higher than wheat (0.037) and rice (0.00001).

Soil salinity is considered one of the most detrimental environmental problems affecting the productivity of many agricultural crops, with negative effects on seed germination, plant vigour, and crop yields. To mitigate these negative effects, it is necessary to restrategize and identify viable options that are environmentally and economically applicable for sustainable agriculture. This review summarizes and evaluates soil reclamation strategies that have been employed and those that could potentially be used, concentrating on the use of legume crops. Apart from the fact that legumes have many nutritional benefits as foods, they are also an attractive option to refertilize degraded and nitrogen‐deficient soils. Thus, the potential use of grain, grass, shrubby, and tree legumes to restore degraded soils requires evaluation. In this paper, we discuss and evaluate why legumes should be considered and used for the reclamation of degraded soils, with a particular focus on salt‐degraded soils. Globally relevant case‐studies that demonstrate how legumes could be used to reclaim salt‐degraded soils are highlighted.

Strategies to deal with global radiation may be related to important aspects of species biology and ecology by reflecting, transmitting or absorbing the radiation of varying wavelengths differently. The elytra capacity to manage infrared, visible and ultraviolet radiations (from 185 to 1400 nm) was assessed with a spectrophotometric analysis in five Canthon species of dung beetles; we calculated the reflectance, transmittance and absorbance capacity of the elytra of these species. These species have different ecologies: two species preferentially inhabit forest areas (Canthon angularis and Canthon lividus lividus), two species preferentially inhabit open areas (Canthon chalybaeus and Canthon tetraodon) including agricultural crops, and one species does not present a clear habitat preference and can be found in both habitats (Canthon quinquemaculatus). All the species show a similar pattern in which the light from shorter wavelengths and higher frequencies is almost entirely absorbed by the elytra, while radiation from longer wavelengths and lower frequencies can mostly pass through the elytra. However, C. quinquemaculatus seems to have significantly higher rates of reflectance and transmittance in the visible‐ and near‐infrared spectrum. This different pattern found in C. quinquemaculatus may be associated with its capacity to establish populations both in agricultural and forest areas., This research was funded by the“PVE”projectMEC/MCTI/CAPES/CNPq/FAPs No 09/2014 of the Ministry ofEducation of Brazil:“Efeito comparado do clima e das mudancßas nouso do solo na distribuicß~ao espacial de um grupo de insetosindicadores (Coleoptera: Scarabaeinae) na Mata Atl^antica”(Process88881.068089/2014-01).VMA would like to thank CAPES (Ministryof Education of Brazil) for a PhD Grant during a research stay inthe Museo de Ciencias Naturales de Madrid (Process 88887.122299/2016-00). MIMH would like to thank CNPq (Science andTechnology Ministry of Brazil, Proc. 309030/2013-7) for aProductivity Grant.

Diseases of agricultural crops caused by fungi have devastating economic and health effects. Fusarium head blight (FHB) is one of the most damaging diseases of wheat and other small grain cereals. FHB reduces agricultural yield while also affecting food supply and safety through deposition of toxins (mycotoxins/phytotoxins). Control of FHB growth and toxin accumulation in grains remain major challenges. While the ultimate goal in the battle against FHB is the development of resistant wheat varieties, the actual use of fully resistant plants that preclude any need for treatment with fungicides remains out of sight. Current antifungals being applied against FHB are generally azole‐based inhibitors. However, usage of these azole‐based fungicides is being complicated by the facts that these are active only during specific short‐lived developmental time periods, fungi are developing increased resistance to them and they are having significant environmental impacts. As such, there is a great need for more targeted, specific and effective antifungal agents to address the significant threat of FHB. This review provides an overview of some of the more promising fungal targets that are currently being investigated for antifungal development.

The influence of agriculture on Australia's nineteenth and twentieth century economic development is well known. While wool's contribution is rightly celebrated, the contribution of agricultural crops has received less attention. This paper focuses on one major staple, wheat, from 1861 to 1939. Both patent data and a new measure of technological progress, the cumulative number of wheat varieties tested for local adoption, are used to quantify the contribution of agricultural innovation to growth. We find innovation in this sector made an important contribution to the growth of total factor productivity over the period.

In applying cross-species extrapolation safety factors from honeybees to other bee species, some basic principles of toxicity have not been included, for example, the importance of body mass in determining a toxic dose. The present study re-analyzed published toxicity data, taking into account the reported mass of the individuals in the identified species. The analysis demonstrated a shift to the left in the distribution of sensitivity of honeybees relative to 20 other bee species when body size is taken into account, with the 95(th) percentile for contact and oral toxicity reducing from 10.7 (based on μg/individual bee) to 5.0 (based on μg/g bodyweight). Such an approach results in the real drivers of species differences in sensitivity-such as variability in absorption, distribution, metabolism, and excretion in and target-receptor binding-being more realistically reflected in the revised safety factor. Body mass can also be used to underpin the other parameter of first-tier risk assessment, that is, exposure. However, the key exposure factors that cannot be predicted from bodyweight are the effects of ecology and behavior of the different species on exposure to a treated crop. Further data are required to understand the biology of species associated with agricultural crops and the potential consequences of effects on individuals at the levels of the colony or bee populations. This information will allow the development of appropriate higher-tier refinement of risk assessments and testing strategies rather than extensive additional toxicity testing at Tier 1. Integr Environ Assess Manag 2016;12:622-626. © 2015 SETAC.

Rosemary Perkins raises some very troubling issues in her opinion piece ‘Are pet parasite products harming the environment more than we think?’ ( VR , 5/12 September 2020, vol 187, p 197). Many vets may not realise that modern flea medications contain neonicotinoids such as imidacloprid. These chemicals are extremely toxic to insects and other invertebrates yet are relatively non-toxic to mammals. Neonicotinoids are now banned from use in outdoor agricultural crops in the EU but not in greenhouse cultivation. The ban was due to concern about the effects of these insecticides on bees and other pollinators. The pristine houseplant …

To meet future world food and fiber demands, plant breeders must increase the rate of genetic improvement of important agricultural crops. One of the biggest obstacles now facing crop scientists is a phenotyping bottleneck. To ease this burden, the emerging technology of unmanned aerial systems (UAS) presents an exciting opportunity. To assess the utility of UAS, it is important to investigate their application across multiple crop species. Terminal plant height is of great importance to maize (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench] breeders and has been hypothesized to be useful but has been logistically impractical to measure in the field. In this study, we statistically analyzed in depth the ability of UAS to estimate height in sorghum (advanced and early generation material) and maize (optimal and late material) and the application of these estimates in breeding programs. We found that UAS explain genotypic variation similarly to ground-truth methods and that the repeatability of the methodology is high (R = 0.61–0.99), indicating effective differentiation of genotypes. Additionally, correlations between ground truth and UAS measurements were moderate to high for all materials (r = 0.4–0.9). Finally, we present a novel application for the technology in the form of high-resolution temporal growth curves. Using these UAS-generated growth curves, new physiological insights can be obtained and new avenues of scientific investigation are possible.

The on-going CRISPR craze is focused on the use of Cas9-based technologies for genome editing applications in eukaryotes, with high potential for translational medicine and next-generation gene therapy. Nevertheless, CRISPR-Cas systems actually provide adaptive immunity in bacteria, and have much promise for various applications in food bacteria that include high-resolution typing of pathogens, vaccination of starter cultures against phages, and the genesis of programmable and specific antibiotics that can selectively modulate bacterial population composition. Indeed, the molecular machinery from these DNA-encoded, RNA-mediated, DNA-targeting systems can be harnessed in native hosts, or repurposed in engineered systems for a plethora of applications that can be implemented in all organisms relevant to the food chain, including agricultural crops trait-enhancement, livestock breeding, and fermentation-based manufacturing, and for the genesis of next-generation food products with enhanced quality and health-promoting functionalities. CRISPR-based applications are now poised to revolutionize many fields within food science, from farm to fork. In this review, we describe CRISPR-Cas systems and highlight their potential for the development of enhanced foods.

Summary Terrestrial plants create roughly 84 Tmol biogenic silicon (BSi) each year. This substantial uptake of dissolved silicon (DSi) by land plants represents an important, yet often overlooked, pathway of Si on the global scale. Agricultural crops account for ~35% of BSi created by land plants globally due to a combination of large biomass and relatively high Si concentrations in the tissue of many crops. In this review, we investigate the global importance of terrestrial BSi fixation by agricultural crops. Using annual data from 1961 to 2012 of the 10 most important crops (ranked by mass produced globally), we quantify how agriculture has altered the amount of BSi created on land. Over this time period, average annual BSi production by the top 10 crops tripled globally, increasing by an additional 39 Gmol Si each year. We refer to this BSi in agricultural crops as human-appropriated biogenic Si (HABSi). Based on projected increases in human populations and land cover change, HABSi is projected to increase by 22–35% by 2050. Human agricultural practices are increasing the size of relatively labile plant BSi pool on land. Considering its bioavailable nature, we suggest that increasing plant BSi on land has the capacity to alter Si availability in downstream receiving waters, although this depends on the fate of harvesting and threshing losses, which varies substantially across the globe. We highlight similarities between the N, P and Si cycles in agricultural settings, such as the often unidirectional flow of Si away from croplands (similar to N) and soil BSi depletion (similar to P). We then address how changing human diets will continue to alter plant BSi cycling in future decades.

Mealiness is known as an important internal quality attribute of fruits/vegetables, which has significant influence on consumer purchasing decisions. Mealiness has been a topic of research interest over the past several decades. A number of destructive and nondestructive techniques are introduced for mealiness detection. Nondestructive methods are more interesting because they are rapid, noninvasive, and suitable for real-time purposes. In this review, the concept of mealiness is presented for potato, apple, and peach, followed by an in-depth discussion about applications of destructive and nondestructive techniques developed for mealiness detection. The results suggest the potential of electromagnetic-based techniques for nondestructive mealiness evaluation. Further investigations are in progress to find more appropriate nondestructive techniques as well as cost and performance.

BACKGROUND A population model can be a useful tool to understand population dynamics under various environmental factors, and can be useful for evaluating the efficacy of new management practices. This study was conducted to construct an oviposition model of overwintered Scirtothrips dorsalis as a part of its whole population model. RESULTS Adult longevity decreased with increasing temperature and ranged from 44.7 days at 13 °C to 9.9 days at 33 °C. S. dorsalis showed a maximum fecundity of 52.6 eggs female−1 at 21 °C, which declined to 13.9 eggs female−1 at 33 °C. Egg development time decreased from 28.41 days at 13 °C to 5.14 days at 29 °C and 5.5 days at 33 °C. An oviposition model was developed on the basis of three temperature-dependent submodels: total fecundity, age-specific oviposition rate and age-specific survival rate models CONCLUSION The oviposition model outputs followed the field occurrence patterns of S. dorsalis egg populations well, with a peak time discrepancy of 3–4 days. Our model should be useful for population modelling of S. dorsalis in agricultural crops. Furthermore, the present model can be independently used for the timing of spraying against S. dorsalis in IPM programmes of various crops. © 2014 Society of Chemical Industry

This paper quantifies the levels of assistance received by producers of the major agricultural crops and animal products in Australia from Federation to the end of World War II. We outline the history of government assistance to the sector after Federation. Six measures of assistance are examined. Then the nominal rates of assistance from these measures are calculated for 20 agricultural products, 14 of which are classified as exportables and 6 as importables. From these product measures of assistance, we construct a series of the production-weighted average nominal rate of assistance for the group of exportable products and for the group of importable products and for the whole sector. Our results show that, from the time of Federation, the pattern of assistance to the sector discriminated persistently and heavily against the exportable agricultural products.

Meloidogyne species pose a significant threat to crop production in Africa due to the losses they cause in a wide range of agricultural crops. The direct and indirect damage caused by various Meloidogyne species results in delayed maturity, toppling, reduced yields and quality of crop produce, high costs of production and therefore loss of income. In addition, emergence of resistance-breaking Meloidogyne species has partly rendered various pest management programmes already in place ineffective, therefore putting food security of the continent at risk. It is likely that more losses may be experienced in the future due to the on-going withdrawal of nematicides. To adequately address the threat of Meloidogyne species in Africa, an accurate assessment and understanding of the species present, genetic diversity, population structure, parasitism mechanisms and how each of these factors contribute to the overall threat posed by Meloidogyne species is important. Thus, the ability to accurately characterize and identify Meloidogyne species is crucial if the threat of Meloidogyne species to crop production in Africa is to be effectively tackled. This review discusses the use of traditional versus molecular-based identification methods of Meloidogyne species and how accurate identification using a polyphasic approach can negate the eminent threat of root knot nematodes in crop production. The potential threat to Africa posed by highly damaging and resistance-breaking populations of ‘emerging’ Meloidogyne species is also examined.

Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic compounds produced predominantly as secondary metabolites by certain species of fungi belonging to the Aspergillus genus. Owing to the significant health risks and economic impacts associated with the presence of aflatoxins in agricultural commodities, a considerable amount of research has been directed at finding methods to prevent toxicity. This review compiles the recent literature of methods for the detoxification and management of aflatoxin in post-harvest agricultural crops using non-biological remediation. © 2013 Society of Chemical Industry

This article presents a mixed-integer programming model for a multitype facility colocation problem with capacity expansion over a multiperiod horizon. This problem is motivated by the emerging U.S. biofuel industry that is rapidly expanding its infrastructure facilities to produce bioethanol from agricultural crops. Each type of facility (e.g., corn- or cellulose-based biorefinery) requires a different type of raw material (e.g., corn or perennial grass), but they produce the same final product (e.g., bioethanol), and colocation of multiple types of facilities results in cost-saving benefits due to complementary production process and byproduct recycling. Multiple solution approaches (i.e., Lagrangian relaxation, Benders decomposition, and accelerated Benders decomposition) are proposed to solve this problem. Numerical experiments show that accelerated Benders decomposition most effectively solves large-sized problems in a short amount of time. Various managerial insights are also drawn from the computational results.

Phytotoxins are secondary microbial metabolites that play an essential role in the development of disease symptoms induced by fungi on host plants. Although phytotoxins can cause extensive-and in some cases devastating-damage to agricultural crops, they can also represent an important tool to develop natural herbicides when produced by fungi and plants to inhibit the growth and spread of weeds. An alternative strategy to biologically control parasitic plants is based on the use of plant and fungal metabolites, which stimulate seed germination in the absence of the host plant. Nontoxigenic fungi also produce bioactive metabolites with potential fungicide and insecticide activity, and could be applied for crop protection. All these metabolites represent important tools to develop eco-friendly pesticides. This review deals with the relationships between the biological activity of some phytotoxins, seed germination stimulants, fungicides and insecticides, and their stereochemistry.

White-tailed deer (Odocoileus virginianus) damage agricultural crops, often leading to signifi- cant economic losses for farmers. We used poly-mesh fence with wings to separate good deer cover from agricultural fields where crop damage by deer occurred primarily along this edge. In these cases, complete enclosure of the field with fencing may be unnecessary. The design used a 2.13-m-high polypropylene mesh fence erected along the wooded edge of a field with either 50-m or 150-m wings extending perpendicular from the fence line and wooded habitat. Fences reduced deer damage in cornfields 13.5% (F1,6 ¼1 , P < 0.001). Average yield in fenced fields (10,211 kg/ha) was 1,708 kg/ha greater than in control fields, which, at US$0.155/kg, equals a net gain of US$265/ha. We found no difference in damage between fences with 50-m and 150-m wings (F1,1 ¼ 0.26, P ¼ 0.695). Costs for materials and labor for erecting partial poly-mesh fences with wings were US$5.56/m and US$1.42/m, respectively. Mean total cost for partial poly-mesh fences with 50-m wings would be US$60.13/ha/year over a 10-year period, compared with US$82.30/ha/year for 150-m wings and US$184.16/ha/year for completely enclosing fields. Expected savings for partial poly-mesh fences with 50-m wings over a 10-year period were US$205/ha/year, as compared with damaged fields without fences. We concluded that poly-mesh fences with 50-m wings were cost-effective at reducing damage by deer to corn. Additional research should be conducted to determine efficacy of the more cost-effective high-tensile and poly-tape fences with wings. 2012 The Wildlife Society.

Traps baited with the sex pheromone blend of (Z7)- and (Z5)-tetradecenyl acetate captured significant numbers of male spotted cutworm moths, Xestia c-nigrum (L.) compared to unbaited traps. Nearly no males were captured in traps baited with (Z7)-tetradecenyl acetate, the major pheromone component. Antennae of spotted cutworm males responded to (Z7)-, (E7)-, (Z5)- and (E5)-tetradecenyl acetate in the laboratory; however there was no response by moths in the field to the E isomers when presented in traps as major and minor components respectively of a binary blend or to the (E7) isomer as a single component. These findings clarify the makeup of a sex attractant that can be used for monitoring X. c-nigrum on agricultural crops in Washington. However, multi-year season-long monitoring of spotted cutworm moths in Yakima Valley apple orchards revealed differential responses to pheromone and blacklight traps. A spring flight period showed a strong moth response to the pheromone compared to blacklight, while a later summer flight period showed a weak moth response to the pheromone relative to blacklight. At this time, we do not know which trap type might best indicate spotted cutworm abundance and risk to crops.

BACKGROUND: Native to Africa, Gambian giant pouched rats (Gambian rats; Cricetomys gambianus Waterh.) are a threatening invasive species on a Florida island, Grassy Key. Gambian giant pouched rats shifted from a domestic pet to invading species after suspected release from a pet breeder. Because of the large size of Gambian rats (weighing up to 2.8 kg), they pose a serious threat to native species (particularly nesting species) and agricultural crops, especially if Gambian rats invade mainland Florida. Also, Gambian rats pose a threat from disease, as they were implicated in a monkeypox outbreak in the midwestern United States in 2003. The United States Department of Agriculture's Wildlife Services has initiated eradication and detection efforts in the Florida Keys, but trapping the sparse population of Gambian rats has proven difficult. RESULTS: Fifteen attractants that could be used in traps for capturing or detecting single or paired Gambian rats were tested. It was found that conspecific scents (i.e. feces and urine) from other Gambian rats were the best treatment for attracting single and paired Gambian rats. Single Gambian rats explored more attractant types than paired Gambian rats. CONCLUSIONS: Effective attractants for use with Gambian rats have been identified, and multiple attractant types should be used to capture or detect the sparse population. It is recommended that mainly urine and feces from Gambian rats be used, but peanut butter, anise, ginger and fatty acid scent could also be useful for attracting the currently small population of Gambian rats on Grassy Key. Published in 2009 by John Wiley & Sons, Ltd.

Examines the relationship of agricultural price policy to changes put into effect in the organisation of the peasant economy in Tanzania during the 1970s. Attention is directed, within the wider context of peasant-state relations in Tanzania, at the adverse consequences of declining real producer prices of agricultural crops for potential innovation in agricultural production.-Author

A closed culture system for the high density culturing of Artemia spp. in 300-liter tanks using a new formula of artificial seawater and micronized waste products from agricultural crops as food is described. Culture conditions are greatly improved by applying a new filter technique and an electronic transparency meter which controls food distributions automatically. A total volume of 6,000 liters of culture water recirculated over a rotating biological contactor, a cross-flow sieve and a plate separator at a flow rate of 3000 liters per hour.Production yields obtained with this culture system, when extrapolated to a 1 m³ tank, indicate that 50 g of brine shrimp cysts can be converted into 20 kg of fresh (wet dry) pre-adult Artemia in 14 days. These results are comparable to those reported earlier with open flow- through conditions.

Nonlethal management alternatives are needed to minimize bird depredation of agricultural crops. We conducted 8 caged feeding tests and 2 field studies to evaluate 2 registered fungicides (GWN-4770, Gowan Company, Yuma, AZ; Quadris®, Syngenta Crop Protection, Greensboro, NC), a neem oil insecticide (Aza-Direct®, Gowan Company), and a novel terpene formulation (Gander Gone, Natural Earth Products, Winter Springs, FL) as avian repellents. For all candidate repellents, red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated and treated rice during preference-testing in captivity. We observed a positive concentration–response relationship among birds offered rice treated with 2,500 ppm, 5,000 ppm, 7,500 ppm, 11,000 ppm, or 22,000 ppm GWN-4770. Relative to pretreatment, blackbirds consumed 34% and 77% less rice treated with 11,000 ppm and 22,000 ppm GWN-4770, respectively, during the concentration–response test. Maximum repellency among other tested compounds was

In this paper a nonlinear mathematical model to study effects of primary and secondary toxicants on the biomass of resources such as forestry, agricultural crops, etc., is proposed and analyzed. The primary toxicant is emitted into the environment with a constant prescribed rate by an external source and a part of which is transformed into a secondary toxicant, which is more toxic, both affecting the resource simultaneously. By using stability theory of differential equations, it is shown that the biomass density of resource attains an equilibrium level, the magnitude of which is smaller than its original (toxicant independent) carrying capacity and it decreases as the emission rate of primary toxicant increases. It is also shown that the decrease in biomass density of resource is more than the corresponding case of a single toxicant due to large transformation and uptake rates and high toxicity of secondary toxicant. It is pointed out that the resource may even become extinct if emission rate of primary toxicant and transformation rate of secondary toxicant are very large and their effects on resource are sufficiently harmful due to large uptake and high toxicity of secondary toxicant which is more toxic.

Bird depredation of agricultural crops is a worldwide problem. New strategies to include chemical repellents are needed to mitigate crop losses. We evaluated 3 preplant seed treatments (Apron XL® LS [Syngenta Crop Protection, Greensboro, NC], Dividend Extreme® [Syngenta], and Maxim® 4 FS [Syngenta]), one foliar insecticide (Karate® with Zeon Technology™ [Syngenta]), and one foliar fungicide (Tilt® [Syngenta]) as potential blackbird repellents in caged feeding trials and a field study. For all repellents tested, red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated and treated rice during preference testing in captivity. We observed a positive concentration–response relationship among birds offered rice treated with 25%, 50%, 75%, 100%, or 200% of the manufacturer label for Dividend Extreme, Karate, and Tilt. Relative to pretreatment, blackbirds ate 32% and 69% less rice treated with 100% and 200% Tilt label rates, respectively, during the concentration–response test. Maximum...

Cet article presente les resultats d'un suivi a long terme de la resistance aux produits phytosanitaires des populations de ravageurs agricoles en Russie. Sur les 45 dernieres annees, le developpement de resistance a ete signale pour 36 especes d'arthropodes nuisibles dans 11 cultures agricoles et des pâtures en relation a presque tous les produits utilises. Le developpement de resistances groupees, croisees et multiples est apparu dans des populations de nombreux organismes nuisibles economiquement importants. Des methodes toxicologiques et phenotypiques (pour le doryphore de la pomme de terre) ont ete concues pour suivre le developpement de la resistance. En se basant sur l'experience acquise pendant le siecle passe, des systemes destines a empecher le developpement de resistances aux insecticides et aux acaricides ont ete elabores. Ces systemes sont bases sur le suivi de la resistance et l'utilisation de mesures phytosanitaires qui minimisent la pression toxique sur les agroecosystemes.

Nonlethal management alternatives are needed to reduce avian depredation of agricultural crops. Caffeine has promise as an effective, economical, and environmentally safe avian repellent, yet formulation improvements are needed for field applications. We included sodium benzoate in subsequent formulations to enhance the solubility of caffeine. Red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated rice and rice treated with 250 ppm or 10,000 ppm caffeine and sodium benzoate in captivity. We observed a positive concentration–response relationship among birds offered rice treated with 250 ppm, 1,000 ppm, 2,500 ppm, 5,000 ppm, 10,000 ppm, or 20,000 ppm caffeine and sodium benzoate. Relative to the pretreatment of the concentration–response test, repellency was >85% for rice treated with our 2,500- to 20,000-ppm treatments. We conducted seed germination experiments and associated residue analyses to evaluate the potential phytotoxicity of various caffeine formulations under contr...

The explicit combination method (ECM; Penman, 1948) to calculate potential evapotranspiration (ETp) is a physically based model using standard climatological data. It is based on an assumption regarding the temperature and humidity at the evaporating surface that is not made in a recursive combination method (RCM; Budyko, 1958). Our objective was to compare the two methods by calculating values of ETp and of actual evapotranspiration (ETa) using hourly weather data collected on 45 d during the warm season in Lubbock, TX. Results show that on hot summer days ECM underestimated the daily value of ETp and of ETa by as much as 25% compared with RCM. The proposed RCM procedure is based on the same physical principles as ECM, but uses iteration to find an accurate answer. It can easily be used with commercially available mathematical software that has proven to be stable. The RCM needs experimental verification before implementation for crop irrigation. T HE TERM POTENTIAL EVAPOTRANSPIRATION, due to Thornthwaite (1948), stands for the maximum rate of water loss by evaporation from the land surface under given atmospheric conditions. The ETa represents values of evapotranspiration (ET) that, applied to well-watered agricultural crops, facilitate the planning and efficient use of water in crop production. It takes account of the role of leaf stomata in causing ETa to be less than ETp. Historically, the methods of relating ETp to weather parameters were empirical and lacked general validity. However, Penman (1948) and Budyko (1958) independently proposed methods to calculate ETp based on known physical principles and standard climatological data, commonly referred to as the combination method. The solution was obtained by combining the equations for the transport of water vapor and sensible heat from or to the land surface with an expression for the radiative energy balance of that surface. For reviews of methods to calculate ETp, see Sellers (1965) and Brutsaert (1982). Penman (1948) derived an explicit equation for ETp by making the assumption that the ratio between the temperature gradient between the surface and the air above and the corresponding humidity gradient, given saturation at the surface, would equal the value of the Clausius-Clapeyron equation at the ambient air temperature. The object of this assumption was the elimination of the surface temperature from the set of equations used in the calculation of ETp (Milly, 1991). However

SUMMARY Globally, virus diseases are common in agricultural crops and have a major agronomic impact. They are countered through the deployment of genetic resistance against the virus, or through the use of a range of farming practices based upon the propagation of virus-free plant material and the exclusion of the virus vectors from the growing crop. We review here the current status of our knowledge of natural virus resistance genes, and consider the future prospects for the deployment of these genes against virus infection.

Weeds typically occur in patches rather than uniformly across a field; however, conventional management practices rely on whole-field management. Site-specific weed management (SSWM), applying control measures only where weeds are located at densities greater than those that cause economic losses, has tremendous potential for economic and environmental benefits. Current commercially available systems can detect green vegetation and activate a herbicide spray nozzle. Researchers are actively exploring how ground-based, aerial, or satellite sensor systems can be further developed to delineate weeds from crops during the growing season. Aerial and satellite systems can provide large-area coverage on a regular basis, but typically do not have the spatial resolution necessary to detect small weeds among agricultural crops, which is necessary if effective control and minimized crop yield losses are to be achieved. Ground-based systems overcome spatial resolution issues and can analyze plant shape characteristics as well as spectral profiles for weed detection. The primary limitation for ground-based sensors is the highly complex computational capabilities and the relatively slow speeds required to allow image processing and sprayer activation in a single operation. To date, economic and technical limitations for SSWM have not favored widespread adoption. However, as research continues and technology advances, the opportunities for site-specific control of weeds will greatly increase.

Biotechnology has enabled the modification of agricultural materials in a very precise way, thereby improving productivity and yields of economically important crops. There are a number of methods available for detecting genetically modified organisms (GMOs). In the present investigation, a qualitative PCR technique has been adopted in order to discriminate between genetically modified and non-modified food products. The qualitative PCR assay employs primers specific for genetic elements that are used to generate genetically engineered agricultural crops. Two of the most common primers used for the detection of GMOs, 35S promoter and NOS 3' terminator, have been tested over a panel of 24 food products purchased from the local market. The results indicated that, out of the 24 food products tested, three products gave positive results with the 35S promoter. The NOS 3' primers gave negative results with all tested samples.

White-tailed deer (Odocoileus virginianus) cause millions of dollars of damage to agricultural crops annually. We tested the effectiveness of propane exploders and Electronic Guards (Pocatello Supply Depot, Pocatello, Id.) for reducing deer damage in cornfields during the silking–tasseling stage of growth. Track-count indices (F2,7=0.70, P=0.532), corn yields (F2,6=0.14, P=0.873), and estimated damage levels (F2,12=1.45 P=0.272) did not differ between experimental and control fields. The size (F2,11=0.08, P=0.924), location (F2,9 =0.30, P =0.750), and percent overlap (F2,9 =0.46, P =0.644) of use-areas of radiomarked female deer in the vicinity of experimental fields did not differ among before, during, and after 18-day treatment periods. In a related study, we placed propane exploders in cornfields within use-areas of 12 radiomarked female deer. The deer did not react appreciably to the devices: the size (F2,17=0.08, P=0.921), location (F2,22=1.37, P = 0.275), and percent overlap (F2,10 = 0.47, ...

Deer (Odocoileus spp.) can cause substantial damage to agricultural crops, resulting in economic losses for producers. We developed a deer-activated bio-acoustic frightening device to reduce white-tailed deer (O. virginianus) damage in agricultural fields. The device consisted of an infrared detection system that activated an audio component which broadcast recorded distress and alarm calls of deer. We tested the device against unprotected controls in cornfields during the silking–tasseling stage of growth in July 2001. The device was not effective in reducing damage: track-count indices (F1,4=0.02, P=0.892), corn yield (F1,9=1.27, P=0.289), and estimated damage levels (F1,10=0.87, P=0.374) did not differ between experimental and control fields. The size (F2,26=1.00, P=0.380), location (F2,25 =0.39, P =0.684), and percent overlap (F2,25 =0.20, P =0.818) of use-areas of radiomarked female deer did not differ between during- and after-treatment periods. We concluded that the deer-activated bio-acou...

Summary 1Improved nutrition may cause an increase in body size in animals, while increased ambient temperature may result in a decrease in body size, as expected from Bergmann's rule. In Israel, during the last 50 years both food availability for animals commensal with humans and ambient temperature have increased. 2Using museum data, temporal changes in body size of five species of carnivorous mammals commensal with humans were examined. 3An increase in body length was found in four species, and appears to be related to improved nutrition owing to a substantial increase in the amount of garbage and agricultural crops available to commensal mammals that has occurred since the establishment of the State of Israel in 1948. 4The larger species were more affected than the smaller ones, apparently because of their higher position in the feeding hierarchy or because of having larger home ranges. 5The increases are convergent with the increase in human body height observed during the past two centuries. 6These changes illustrate the fast rate of animal response to changing environmental conditions.

The results from multienvironment field performance trials of cultivars are usually analysed as two-way classification data with rows=genotypes/cultivars and columns=environments (locations and/or years). To reduce the impact of genotype × environment interaction effects, one commonly stratifies genotypes/cultivars or environments by cluster analysis techniques into homogeneous groups so that interactions within groups are minimized. By such a stratification, for example of test sites, with regard to similarity of genotype × environment interactions and the selection of only one representative test site from each group, the overall number of necessary test sites for yield trials can be reduced. In the literature, many clustering techniques have been proposed. Systematic comparisons between different cluster methods, however, are rather rare. A single cluster method is characterized by `measure of distance', `stopping criterion', `algorithm' and `level of significance'. In this paper, 11 clustering techniques were applied to extensive yield data sets of several agricultural crops (faba bean, fodder beet, oat, winter oilseed rape and sugar beet) from the official registration trials of the German `Bundessortenamt'. The results were compared with each other using two proposed parameters: measure of resemblance (for two classifications) and cluster size (for one classification). Neither the level of significance nor the algorithm has a substantial impact on the resulting clusters. The final results of clustering are therefore mainly determined by the stopping criterion with its associated measure of distance. If one uses tests for crossover interactions as stopping criteria, the resulting clusters are larger than the resulting clusters for the F-test of conventional interactions in an analysis of variance. The cluster size decreases with increasing sensitivity of the tests that are used as stopping criteria. Finally, recommendations for the choice and handling of clustering techniques for practical applications are given. Beitrage zur Analyse von Genotyp × Umwelt-Interaktionen: Experimentelle Ergebnisse zur Anwendung und zum Vergleich von Clusterverfahren zur Gruppierung von Standorten Die Ergebnisse von Leistungsprufungen liegen ublicherweise in der Form von kreuzklassifizierten Datensatzen vor: Zeilen=Genotypen/Sorten und Spalten=Umwelten (Standorte und/oder Untersuchungsjahre). Um die Effekte der Genotyp × Umwelt-Wechselwirkungen berucksichtigen zu konnen, werden Genotypen/Sorten bzw. Umwelten mit Hilfe von Clusterverfahren haufig so in homogene Gruppen eingeteilt, das die Wechselwirkungen innerhalb der Gruppen minimiert werden. Durch eine Gruppierung von Versuchsstandorten hinsichtlich der Ahnlichkeit der Genotyp×Umwelt-Wechselwirkungen und die danach folgende Auswahl von je einem reprasentativen Standort aus jeder Gruppe last sich die Anzahl der erforderlichen Versuchsstandorte fur Leistungsprufungen reduzieren. In der Literatur wurden zwar viele Clustertechniken vorgeschlagen, doch systematische Vergleiche zwischen den verschiedenen Verfahren liegen praktisch nicht vor. Ein einzelnes Clusterverfahren ist charakterisiert durch: Distanzmas, Abbruchkriterium, Algorithmus und Signifikanzniveau. In der vorliegenden Arbeit werden nun elf verschiedene Clusterverfahren auf umfangreiche Wertprufungsdatensatze verschiedener landwirtschaftlicher Kulturarten (Fababohne, Futter- und Zuckerrube, Hafer, Winterraps) des Deutschen Bundessortenamtes angewendet. Die Ergebnisse werden mit Hilfe der beiden vorgeschlagenen Maszahlen `Ahnlichkeitsmas' (fur zwei Klassifikationen) und `Clustergrose' (fur eine Klassifikation) miteinander verglichen. Mit Blick auf die resultierenden Klassifikationen erweisen sich der Algorithmus und auch das Signifikanzniveau als relativ unbedeutend, so das die Clusterergebnisse im Wesentlichen durch das Abbruchkriterium mit demdazugehorigen Distanzmas bestimmt werden. Falls man Tests fur Ranginteraktionen als Abbruchkriterium verwendet, sind die resultierenden Cluster groser als beim F-Test der Varianzanalyse auf konventionelle Interaktionen. Die Clustergrose nimmt mit zunehmender Sensibilitat der Tests, die man als Abbruchkriterium verwendet, ab. Abschliesend werden konkrete Empfehlungen fur die Auswahl und Handhabung von Clusterverfahren fur praktische Anwendungen gegeben.

Tamarisk (Tamarix aphylla) has been used for windbreaks near agricultural crops and as shade trees in rural desert margins in Iran. Symptoms associated with tamarisk witches' broom (TWB) disease, including proliferation of shoots with …

Transpiration is the main part of the water balance in the system soil-plant during the vegetation period. Its determination or calculation is essential for modeling of soil moisture content or solute transport. Transpiration is difficult to quantify because it is influenced by the atmosphere, the soil, and the plants. This paper describes the potential and limitations of plant physiological methods (sap flow, gas exchange, leaf water potential) to estimate the transpiration. A weighable lysimeter was used as reference method. Results are shown for corn [Zea mays L.] and rape [Brassica napus L.]) for the years 1998 and 1999. At days without rain the diurnal transpiration rates, determined by the plant physiological methods and by the lysimeter differ by less than 12%. The results demonstrate that the plant physiological methods applied are important for an understanding of the complex transpiration process. Limitations lie in the difficulties in up-scaling, and the impossibility of measurements of the absolute actual transpiration rates of agricultural crops for longer periods like months or years. Zur Eignung pflanzenphysiologischer Messungen fur die Bestimmung der Transpiration landwirtschaftlicher Pflanzenbestande Wahrend der Vegetationsperiode hat die Transpiration den entscheidenden Anteil an der Wasserbilanz. Aufgrund der vielschichtigen Einflussfaktoren ist sie immer noch eine schwer zu bestimmende Grose. In dieser Arbeit werden die Ergebnisse der pflanzenphysiologischen Messungen (Saftfluss, Gaswechsel und Blattwasserpotenzial) fur die Untersuchungsjahre 1998 und 1999 mit den Fruchtarten Raps [Brassica napus L.] und Mais [Zea mays L.] vorgestellt und die Qualitat der genutzten Methoden bewertet. Als Referenzmethode dient ein wagbares Lysimeter. Fur niederschlagsfreie Perioden ergibt sich eine gute Ubereinstimmung zwischen den mit dem Lysimeter und dem Minikuvetten- bzw. Dynagage-System gemessenen Transpirationsraten. Die Unterschiede sind kleiner als 12%. Trotz technischer Probleme, Schwierigkeiten beim up-scaling und eines hohen personellen Betreuungsaufwandes bei ihrem Einsatz sind pflanzenphysiologische Messungen fur ein besseres Prozessverstandnis unerlasslich. Als alleinige Verfahren zur Bestimmung der Bestandesverdunstung uber langere Perioden sind derartige Systeme dagegen nicht geeignet.

Yield losses in agricultural crops as a result of sulphur deficiency are increasing in the UK, because of the decrease in sulphur dioxide emissions and changes in fertiliser practices. Therefore, there is a need for a reliable and practical diagnostic indicator to predict early in the growing season whether it is necessary to apply S fertiliser, but also to avoid the application of fertiliser when not necessary. A successful diagnostic indicator should be reliable and stable throughout plant development, but also easily measured with great accuracy and as little effort as possible. In this paper the difficulties and problems with currently used diagnostic tests for S deficiency, such as total S, sulphate or the N:S ratio, will be discussed. A more reliable and practical indicator of S deficiency is the malate:sulphate peak area ratio which is at present being developed for use by commercial laboratories and their customers.