Herbicide resistance in Palmer amaranth and waterhemp is on the rise and poses a great concern to growers in the United States. A multistate screening was conducted for these two weed species in the United States to assess their sensitivity to glufosinate, dicamba, and 2,4-D. The screening was designed to understand the weed sensitivity landscape and emerging trends in resistance evolution by testing each herbicide at its respective label rate and at half the label rate. A total of 303 weed seed accessions from 21 states representing 162 Palmer amaranth and 141 waterhemp seeds were collected from grower fields in 2019 and screened in greenhouse conditions. Statistical power of different sample sizes and probability of survivors in each accession were estimated for each species and herbicide treatment. Overall, the efficacy of glufosinate, dicamba, and 2,4-D against all these accessions was excellent, with greater than 90% average injury. The variability in herbicide injury, if any, was greater with half the label rate of 2,4-D in some Palmer amaranth accessions, while waterhemp accessions had exhibited variable sensitivity with half the label rate of dicamba and glufosinate. The study highlights the value of monitoring weeds for herbicide sensitivity across broader landscape and the importance of glufosinate, dicamba, and 2,4-D herbicides in managing troublesome weeds as part of a diversified weed control program integrated with other chemical, mechanical and cultural practices.

From the seventh century AD, successive Islamic polities were established around the Mediterranean. Historians have linked these caliphates with the so-called ‘Islamic Green Revolution’—the introduction of new crops and agricultural practices that transformed the economies of regions under Muslim rule. Increasingly, archaeological studies have problematised this largely text-based model of agrarian innovation, yet much of this research remains regionally and methodologically siloed. Focusing on the Western Mediterranean, the authors offer a theoretically informed, integrated environmental archaeology approach through which to contextualise the ecological impact of the Arab-Berber conquests. Its future application will allow a fuller evaluation of the scale, range and significance of agricultural innovations during the ‘medieval millennium’.

Se presentan los resultados del estudio de la colección del sitio Puente del Diablo (SSalLap20) ubicado en la cabecera del Valle Calchaquí (La Poma, Salta, Argentina). Mediante el estudio de los materiales, registros, libretas de campo y nuevos análisis, se caracterizan cuatro enterratorios, dos de inicios del Holoceno con modalidades funerarias no descritas previamente. Asimismo, se caracteriza el material lítico, faunístico y vegetal; en este último caso se reportan especies domesticadas, entre ellas una semilla de poroto fechada por AMS, siendo el registro directo más temprano del valle. Los enterratorios aportan no sólo al entendimiento de la funebria en los albores del Holoceno —práctica que cuenta con escasos registros en la región— sino también al fechado directo más temprano sobre restos humanos de la zona valliserrana del Noroeste argentino.

The existing literature has demonstrated that both ethnic and economic factors affect a vote decision in African democracies. I show that there is a meaningful interaction between the two cleavages in their influence on voting. In particular, I argue for political salience of agricultural subsectors that shape the electoral consequences of economic performance in the context where agricultural policy affects the livelihood of the majority population. Relying on the analyses of the 2007 and 2013 elections in Kenya, I illustrate how likely an individual, who is attached to a politically coherent ethnic group, votes for a candidate, the majority of whose ethnic members engage in the same industry as the voter himself regardless of the candidate's ethnicity. The results show that the sector factor reinforces the positive and negative effects of ethnic communities on incumbent support, and also explains voting by ethnic minorities whose motives for voting are not ethnic.

The introduction of agriculture is a key defining element of the Neolithic, yet considerable debate persists concerning the nature and significance of early farming practices in north-west Europe. This paper reviews archaeobotanical evidence from 95 Neolithic sites (c. 4000–2200 cal bc) in Wales, focusing on wild plant exploitation, the range of crops present, and the significance of cereals in subsistence practices. Cereal cultivation practices in Early Neolithic Wales are also examined using cereal grain stable carbon (δ13C) and nitrogen (δ15N) isotope analysis. The Early Neolithic period witnessed the widespread uptake of cereals alongside considerable evidence for continued wild plant exploitation, notably hazelnuts and wild fruits. The possibility that wild plants and woodlands were deliberately managed or altered to promote the growth of certain plants is outlined. Small cereal grain assemblages, with little evidence for chaff and weed seeds, are common in the Early Neolithic, whereas cereal-rich sites are rare. Emmer wheat was the dominant crop in the Early Neolithic, while other cereal types were recorded in small quantities. Cereal nitrogen isotope (δ15N) values from Early Neolithic sites provided little evidence for intensive manuring. We suggest that cultivation conditions may have been less intensive when compared to other areas of Britain and Europe. In the later Neolithic period, there is evidence for a decline in the importance of cereals. Finally, the archaeobotanical and crop isotope data from this study are considered within a wider European context.

Se presentan los primeros resultados obtenidos del estudio tecnológico-funcional de un conjunto de 55 cabezales de hachas o azuelas líticas asignadas al período prehispánico tardío (1500–360 años aP) de las Sierras de Córdoba, Argentina. A partir del análisis de sus atributos tecnológicos (peso, agudeza y largo de los filos, etc.) y de los rastros de uso utilizando aumentos de 20–50x, se argumenta que un número significativo de instrumentos fue utilizado para realizar tareas que involucraron el contacto con sedimentos abrasivos, probablemente para cortar y arrancar elementos leñosos del sotobosque a nivel del suelo. Una proporción del conjunto evidenció rastros de uso exclusivamente asociados al trabajo sobre maderas, como pulido y micro-estrías restringidas a la periferia de los filos. Se concluye que los grupos tardíos desarrollaron artefactos pulidos costosos para cumplir efectivamente con la apertura y mantenimiento de claros en el bosque serrano, ya sea para el cultivo, la construcción de viviendas o incrementar la capacidad reproductiva de plantas silvestres de las cuales dependían, entre otros motivos. De esta manera, comprender la función de las hachas o azuelas tardías es fundamental para discutir las actividades productivas y la modificación antrópica del paisaje propuesta para la región a fines del Holoceno.

Landraces (including heritage varieties) are an important agrobiodiversity resource offering considerable value as a buffer against crop failures, as a crop for niche markets, and as a source of diversity for crop genetic improvement activities underpinning future food security. Home gardens are reservoirs of landrace diversity, but some of the accessions held in them are vulnerable or threatened with extinction. Those associated with seed saving networks have added security, for example, ca. 800 varieties are stored in the Heritage Seed Library (HSL) of Garden Organic, UK. In this study, Amplified Fragment Length Polymorphisms-based genetic analysis of accessions held in the HSL was used to (a) demonstrate the range of diversity in the collection, (b) characterize accessions to aid collection management and (c) promote broader use of the collection. In total, 171 accessions were included from six crops: Vicia faba L., Pisum sativum L., Daucus carota L., Cucumis sativus L., Lactuca sativa L. and Brassica oleracea L. var. acephala (DC.) Metzq. Average expected heterozygosity ranged from 0.18 to 0.28 in D. carota; 0.02–0.18 in P. sativum; 0.05–0.18 in L. sativa; 0.15–0.26 in B. oleracea var. acephala; 0.15–0.37 in C. sativus and 0.07–0.36 in V. faba. Genetic diversity and Fst values generally reflected the breeding system and cultivation history of the different crops. Comparisons of the diversity found in heritage varieties with that found in commercial varieties did not show a consistent pattern. Principal coordinates analysis and Unweighted Pair Group Method with Arithmetic Mean cluster analysis were used to identify four potential duplicate accession pairs.

A segment of the debate surrounding the commercialization of genetically engineered (GE) crops, such as glyphosate-resistant (GR) crops, focuses on the theory that implementation of these traits is an extension of the intensification of agriculture that will further erode the biodiversity of agricultural landscapes. A large field-scale study was conducted in 2006 in the United States on 156 different field sites with a minimum 3-yr history of GR corn, cotton, or soybean in the cropping system. The impact of cropping system, crop rotation, frequency of using the GR crop trait, and several categorical variables on emerged weed density and diversity was analyzed. Species richness, evenness, Shannon's H′, proportion of forbs, erect growth habit, and C3 species diversity were all greater in agricultural sites that lacked crop rotation or were in a continuous GR crop system. Rotating between two GR crops (e.g., corn and soybean) or rotating to a non-GR crop resulted in less weed diversity than a continuous GR crop. The composition of the weed flora was more strongly related to location (geography) than any other parameter. The diversity of weed flora in agricultural sites with a history of GR crop production can be influenced by several factors relating to the specific method in which the GR trait is integrated (cropping system, crop rotation, GR trait rotation), the specific weed species, and the geographical location. The finding that fields with continuous GR crops demonstrated greater weed diversity is contrary to arguments opposing the use of GE crops. These results justify further research to clarify the complexities of crops grown with herbicide-resistance traits, or more broadly, GE crops, to provide a more complete characterization of their culture and local adaptation.

We examine how changes in yield variability affect the welfare of cereal grain and oilseed buyers and producers around the world. We simulate trade patterns and welfare for 21 countries with a Ricardian trade model that incorporates bilateral trade costs and crop yield distributions. The model shows that world trade volumes would need to increase substantially if crop yield variability were to rise. Net welfare effects, however, are moderate so long as countries do not resort to policies that inhibit trade, such as export restrictions or measures to promote self-sufficiency in crops. Low-income countries suffer the most from increases in yield variability, due to higher bilateral trade costs and lower-than-average productivity.

There are many quality targets in cereals that could generate step-change improvements in nutritional or food-processing characteristics. For instance, levels of acrylamide, soluble and insoluble fibre, antioxidants, allergens and intolerance factors in food are, to a large extent, determined by the genetics of the raw materials used. However, improvements to these traits pose significant challenges to plant breeders. For some traits, this is because the underlying genetic and biochemical basis of the traits is not fully understood but for others, there is simply a lack of natural genetic variation in commercially useful germplasm. One strategy to overcome the latter hindrance is to use wide crosses with more exotic germplasm; however, this can bring other difficulties such as yield loss and linkage drag of deleterious alleles. As DNA sequencing becomes cheaper and faster, it drives the research fields of reverse genetics and functional genomics which in turn will enable the incorporation of desirable traits into crop varieties via molecular breeding and biotechnology. I will discuss the evolution of these techniques from conventional genetic modification to more recent developments in targeted gene editing and the potential of biotechnology to complement conventional breeding methods. I will also discuss the role of risk assessment and regulation in the commercialisation of GM crops.

This study investigates the long-term adjustments to drought by crop and livestock sectors using a dynamic partial equilibrium quarterly model of the U.S. agricultural economy. Results show that short-term drought effects including increases in crop and forage prices are in tandem with decreased live cattle prices resulting from drought-induced beef cattle herd liquidation. Crop price increases in the long run cause livestock inventory reductions, leading to fewer animals moving through the U.S. meat supply chain and increased livestock prices. Longer-term market adjustments cause a significant decrease in consumer surplus, and prolonged drought amplifies and extends the model-predicted results.

The impact of an ad valorem pesticide tax on cropping patterns and pesticide use was examined in the South Central Texas Crop Reporting District. Output supply equations were econometrically estimated and used in the simulation. A 25 percent tax on pesticide was estimated to have major impacts on cropping patterns and on pesticide use. Assuming other input and output prices were unaffected, the supply of one important crop would fall by more than half. Demand for some of the highly soluble and persistent pesticides, which present the greatest threat to groundwater quality, would also decrease substantially (some as much as 50 percent).

The goal of zero-waste is one of the main challenges of modern steel industry, which over the past 20 years has been committed to increase the recovery and the use of by-products generated during the ironmaking and steelmaking processes. Among the main by-products generated during iron and steel production, such as slags, dusts and sludges, slags constitute about 90% of the total. Slags are currently used in various fields (such as cement production, road construction, environmental recovery in landfill covers, as fertilizer and soil conditioner, etc.) according to their chemical features, which depend on production process origin. In Italy, in particular for example, BF (Blast Furnace) slag is used for cement production while BOF (Basic Oxygen Furnace) slag without iron (inert slag) is used as landfill cover, in compliance with Italian legislation. In Germany, BF and BOF slag use as fertlisers and liming materials has a long tradition. Although in recent years slag use has increased, the application for agriculture purposes needs to be further investigated. Slag can be used as a soil conditioner (high content of Ca and Mg), Si supply (improves the crops resistance to pests and diseases), P fertilizer production and micro-nutrients supply. Use of slags can affect human health and environment, because of heavy metal content, which can leache to groundwater or be transferred to surface water. The assessment of risk to the environment based on slag application requires further investigation. This represents an opportunity for both the steel and fertilizer industries to promote natural resources savings, CO2 emission reductions, landfill waste prevention as well as social awareness of sustainability of some industrial activities. The BOF slag has been shown to be useful as liming material for acidic soil amendment and it can replace commercial fertilizers. Different effects on crop yields and on soil parameters can be found, depending on soil characteristics and climate conditions. In Middle Europe, with humid climate, lime losses through leaching of up to 0.5 t CaO/ha have to be replaced with liming material to prevent acidification. Evaluation of long-term field trials with slag liming materials can give information about the impact of slag applications on crop management and the environment. In Mediterranean regions, such as in Italy, arable soils rarely show acidic characteristics. Alkaline soils from coastal areas are often rich in sodium content, due to seawater intrusion and irrigation with saline water. The aim of this research is also to investigate the application of BOF slag to these soils, in order to assess the effect of Ca contained in slag in balancing negative Na effects. This paper is based on the preliminary study and experiments carried out within an ongoing RFCS (Research Fund for Coal and Steel) project.

Oribius species are small flightless weevils endemic to the island of New Guinea and far northern Cape York, Australia. The adults feed externally on leaves, developing fruit and green bark, but their impact as pests and general host use patterns are poorly known. Working in Eastern Highlands Province, Papua New Guinea, we carried out structured host use surveys, farmer surveys, shade-house growth trials and on-farm and on-station impact trials to: (i) estimate the host range of the local Oribius species; (ii) understand adult daily activity patterns; (iii) elucidate feeding habits of the soil dwelling larvae; and (iv) quantify the impacts of adult feeding damage. Oribius inimicus and O. destructor accounted for nearly all the Oribius species encountered locally, of these two O. inimicus was the most abundant. Weevils were collected from 31 of 33 plants surveyed in the Aiyura Valley, and a combination of farmer interviews and literature records provided evidence for the beetles being pestiferous on 43 crops currently or previously grown in the Highlands. Adult weevils had a distinct diurnal pattern of being in the upper plant canopy early in the morning and, to a lesser extent, again late in the afternoon. For the remainder of the day, beetles resided within the canopy, or possibly off the plant. Movement of adults between plants appeared frequent. Pot trials confirmed the larvae are root feeders. Quantified impact studies showed that the weevils are damaging to a range of vegetable and orchard crops (broccoli, capsicum, celery, French bean, Irish potato, lettuce, orange and strawberry), causing average yield losses of around 30–40%, but up to 100% on citrus. Oribius weevils pose a significant and, apparently, growing problem for Highland's agriculture.

Understanding the compensatory responses of crops to pest damage is important in developing pest thresholds. Compensation for pest damage in crops can occur at the plant level, where the architecture, growth dynamics and allocation patterns of damaged plants are altered, allowing them to recover or, at the crop level, where differential damage between plants may alter plant-to-plant interactions. We investigated growth and yield of cotton (Gossypium hirsutum L.) following non-uniform manual defoliation of seedlings. This partially replicates real pest damage and is valuable in understanding crop-level responses to damage because it can be inflicted precisely. Damage distributions included damaging 0, 25, 50, 75 or 100% of the plants. Damage intensity for the damaged plants was varied by removing 100 or 75% of each true leaf when plants had two, four and six true leaves. At the crop level, yield loss increased as the proportion of plants damaged and intensity of damage per damaged plant increased. Neighbour interactions occurred; undamaged plants with damaged neighbours grew larger and yielded better than undamaged plants with undamaged neighbours, while the converse applied for damaged plants with undamaged neighbours. Neighbour interactions were influenced by the intensity of damage and were stronger when 100% of the leaf area was removed than when 75% was removed. At the crop level, when compared with yield estimates based on yield of plants from uniformly damaged or undamaged plots, these interactions resulted in higher yield than expected (+8%). This suggests that damage distribution may have to be considered in studies where artificial or real pest damage is inflicted uniformly on plants.

In a sub-Saharan African context, limited natural resources, infectious diseases, including those transmitted by arthropod vectors, and chronic exposure to food contaminated with mycotoxin-producing fungi which, among others, are vectored by insects, are among the major constraints to human health. Thus, pest control should be an important component in human health improvement projects. It appears that the advantages of preventive over curative methods are rarely recognised in Africa, with more emphasis being given to the search for the ‘silver bullet’ than to integrated control approaches. Integrated pest management (IPM) systems can be assigned to different decision-making levels as well as to different integration levels, combining ecological (individual pest species, species communities, species assemblages) and management (crop, cropping systems, farms, communities) levels with the respective control systems. These levels produce a highly structured environment for decision-making, in which the use of modern information technology is important. Case studies show that IPM systems are developed and implemented at four integration levels, whereby most work is done on the lowest integration level, addressing a single pest or pest complex attacking a particular crop, group of livestock or human population, and the respective control measures undertaken. Coordinated efforts to develop and implement supplementary IPM systems at higher levels are concluded to be important elements in integrated pest management and a further contribution to human health improvement and poverty alleviation.

Cutworms, semiloopers, budworms and armyworms in the genera Agrotis, Chrysodeixis, Heliothis, Mythimna, Persectania and Spodoptera are important pasture and crop pests in Australia. They comprise both cosmopolitan species, such as A. ipsilon, H. armigera, M. separata and S. exempta and endemic species such as A. infusa, H. punctigera, M. convecta, P. ewingii and P. dyscrita. Although the cosmopolitan species are major pests of parts of Asia and Africa, they are, with the exception of H. armigera, less important agricultural pests in Australia than their endemic counterparts. The latter are widely distributed outside cropping areas, because they breed on a wide range of native host plants as well as on introduced crops and pastures and also have the potential to invade cropping areas from native habitats. The cosmopolitan species are largely confined to tropical and subtropical summer crops and improved pastures of north and east Australia where chronic infestations often develop although major outbreaks and migration out of cropping areas are rare. Periodic outbreaks of endemic species result from an unusually favourable growth of vegetation in early autumn, following drought-breaking rains in the inland. Moths arrive in the rain-affected areas as a result of migration and concentration by rain-bearing troughs and depressions. Southward migration of their progeny occurs in spring on warm northerly airflows produced ahead of eastward-moving cold fronts and results in invasions of temperate crops and pastures. Migration also occurs in anticyclonic conditions, resulting in an extensive redistribution of populations and is adapted to the erratic distribution of rainfall in inland Australia. Among cosmopolitan species, only Spodoptera spp. cause outbreaks which are infrequent and occur with the onset of summer rains in coastal and sub-coastal areas. Most movements of cosmopolitan species are confined within cropping areas although migration from coastal to inland crops, under the influence of prevailing SE winds, and in frontal systems, troughs and storm outflows, is also suspected.