Search

Citrus Huanglongbing (HLB), also known as citrus greening, is one of the most devastating citrus diseases worldwide. Candidatus Liberibacter asiaticus (CLas) is the most prevalent strain associated with HLB, which is yet to be cultured in vitro. None of the commercial citrus cultivars are resistant to HLB. The pathosystem of Ca. Liberibacter is complex and remains a mystery. In this review, we focus on the recent progress in genomic research on the pathogen, the interaction of host and CLas, and the influence of CLas infection on the transcripts, proteins, and metabolism of the host. We have also focused on the identification of candidate genes for CLas pathogenicity or the improvements of HLB tolerance in citrus. In the end, we propose potentially promising areas for mechanistic studies of CLas pathogenicity, defense regulators, and genetic improvement for HLB tolerance/resistance in the future.

The Banana Bunchy Top Disease (BBTD), caused by the Banana Bunchy Top Virus (BBTV) is the most important and devastating in many tropical countries. BBTD epidemiology has been little studied, mixed landscape smallholder systems. The relative risks associated with this disease vary between geographical areas and landscapes. This work analyzed the management and vegetation conditions in smallholder gardens to assess the factors linked to landscape-level BBTV transmission and management. Mapping was done in this study area which is in a BBTD-endemic region, involving farmers actively managing the disease, but with household-level decision making. A spatial scanning statistic was used to detect and identify spatial groups at the 5% significance threshold, and a Poisson regression model was used to explore propagation vectors and the effect of surrounding vegetation and crop diversity. Spatial groups with high relative risk were identified in three communities, Dangbo, Houéyogbé, and Adjarra. Significant associations emerged between the BBTD prevalence and some crop diversity, seed systems, and BBTD management linked factors. The identified factors form important candidate management options for the detailed assessment of landscape-scale BBTD management in smallholder communities.

The third-largest country in the production of fresh fruit in the world, Brazil stands out for having an ample capacity of adaptation of exotic fruit trees, due to its edaphoclimatic conditions, which added to already established cultural practices, allows the achievement of high yields. In addition, the country has one of the largest agrobiodiversities in the world, having native fruit species with high potential for consumption exploitation, however, many times these fruits do not receive any value and are neglected by popular ignorance, presenting low participation in the fruit market. Therefore, the present study aimed to identify the pattern of fruit consumption, analyze popular knowledge about exotic and native fruit trees and verify the potential for insertion of native species from Brazil in the fruit market. It was observed that the consumption of fruit is lower than that recommended by the World Health Organization (WHO), is composed mostly of exotic fruit acquired in supermarkets. Despite the lack of understanding of the terms of fruit classification based on the center of origin, the research participants, consisted mostly of people with higher education, understand which species belong to the Brazilian flora and which ones have been introduced in the national territory, and demonstrate awareness of the importance of native species and the barriers that prevent insertion in the market in larger quantities and affirm that they would like to consume more native fruits, which demonstrates the potential of Brazilian fruits. Brasil es el tercer productor mundial de frutas frescas en el mundo, destacándose por tener una amplia capacidad de adaptación productiva de frutales exóticos, debido principalmente a sus condiciones edafoclimáticas, que sumadas a las prácticas culturales, permiten lograr altas producciones. Adicionalmente, Brasil es dueño una de las mayores riquezas en agrobiodiversidad, contando con especies de frutas nativas con alto potencial de explotación para el consumo. Esas frutas muchas veces no reciben el valor debido, siendo desconocidas para una representativa parte de la población y como consecuencia, teniendo baja participación en el comercio de frutas brasileño. Ante este escenario, el presente estudio tuvo como objetivo identificar el patrón de consumo de frutas, analizar el conocimiento popular sobre frutales exóticos y nativos, y verificar el potencial de inserción de especies nativas de Brasil en el mercado de frutas. Se observó que el consumo de fruta es menor al recomendado por la Organización Mundial de la Salud (OMS), compuesto en su mayoría por frutas exóticos adquiridos en supermercados. A pesar de la falta de entendimiento de los términos de clasificación de frutas en cuanto al centro de origen, los participantes de la investigación, principalmente comprendido por personas con educación superior, identifican qué especies pertenecen a la flora brasileña y cuáles fueron introducidas en el territorio nacional, comprenden la importancia de las especies nativas y las barreras que impiden su ingreso al mercado en mayores proporciones, manifestando que les gustaría consumir más frutas nativas, lo que demuestra el potencial de las fruticultura brasilera. Terceiro maior país em produção de frutas frescas no mundo, o Brasil destaca-se por apresentar ampla capacidade de adaptação produtiva de fruteiras exóticas devido, principalmente, às suas condições edafoclimáticas que somados a práticas culturais já estabelecidas, permitem alcançar altas produções. Além disso, o país é detentor de uma das maiores agrobiodiversidades mundiais, possuindo espécies nativas frutíferas com alto potencial de exploração do consumo. Porém, muitas vezes essas frutas não recebem o devido valor, sendo negligenciadas pelo desconhecimento popular, e, consequentemente, apresentam baixa participação no comércio de frutas do Brasil. Diante deste cenário, o presente trabalho teve por objetivo identificar o padrão de consumo de frutas, analisar o conhecimento popular sobre fruteiras exóticas e nativas e verificar a potencialidade de inserção de espécies nativas do Brasil no mercado de frutas. Observou-se que, o consumo de frutas é inferior ao recomendado pela Organização Mundial da Saúde (OMS), sendo composto em sua maioria de fruteiras exóticas adquiridas em supermercados. Apesar da falta de entendimento dos termos de classificação de frutas quanto ao centro de origem, os participantes da pesquisa, compreendidos majoritariamente por pessoas que possuem ensino superior, conhecem quais espécies são pertencentes à flora brasileira e quais foram introduzidas no território nacional. Além disso os entrevistados demonstram consciência da importância das espécies nativas e dos entraves que impedem a inserção no mercado em maiores quantidades, afirmando que gostariam de consumir mais frutas nativas, o que demonstra a potencialidade da fruticultura nacional.

La presente guía está destinada a los profesionales que actúan en el ámbito productivo vinculado a los cultivos frutícolas de hoja caduca (pepita y carozo) y vides, y que se desenvuelven dentro del paradigma productivista. Para futuros paradigmas, posiblemente no tenga ningún valor. En primer lugar, se detalla un listado donde figuran todos los fungicidas registrados con presencia en los comercios de la región, junto con el grupo químico al que pertenecen y el riesgo al desarrollo de resistencia que se le asigna a cada grupo. Esto permite desarrollar un esquema de rotación de activos para evitar resistencia. Luego, se detalla para cada cultivo, los principios activos registrados y con presencia comercial en la región, su eficacia en el control de las principales enfermedades, dosis recomendadas, tiempos de carencia correspondientes, límite máximo de residuos para la legislación argentina, Brasil, mercado más exigente y Codex. Los principios activos considerados se agrupan en cada caso de acuerdo al grupo químico al que pertenecen. La información anterior se complementa con otros fungicidas registrados en cada cultivo, pero no disponibles en el comercio regional en 2021, ya sea porque fueron retirados o porque aún sus compañías no los distribuyen. Los cultivos considerados son once: almendros, cerezo, ciruelo, duraznero, nectarinas, nogales, peral, manzano, membrillero, vid de mesa y vid de vino. Finalmente, se incluye un listado de aquellos fungicidas registrados para uso en poscosecha en los mismos cultivos considerados, y sus LMR correspondientes a la legislación argentina. Es sabido que en nuestro país, una cosa son los activos registrados y otra los activos que realmente se necesitan utilizar, y que ambos grupos pueden no ser coincidentes. Esta guía pone en evidencia esta distorsión, y la necesidad de resolverla. Si consideramos el número de grupos químicos disponibles en un cultivo para controlar cualquiera de las enfermedades que se presentan, entre los once cultivos considerados en esta Guía, hay tres situaciones: Sin restricciones: cerezos, durazneros, nogales, perales, manzanos, y uva de mesa; Con ligeras restricciones: almendros y ciruelos; Con fuertes restricciones: nectarinas, membrilleros y vid vinífera. Una de las causas se debe a que el registro se realiza por cultivo y no por patógeno en cultivos del mismo género, como por ejemplo durazneros y ciruelos; o cerezos y nectarinas. Así, por ejemplo, el fungicida fosetyl aluminio, registrado en cerezos, perales y manzanos para el control de phytophtora, o en uva de mesa para control de peronóspora, no se encuentra registrado en durazneros o nectarinas para la primer enfermedad, o en vides viníferas para la segunda. LOS LMR DE ARGENTINA SON LOS VIGENTES EN MAYO DE 2021 http://www.senasa.gob.ar/normativas/resolucion-934-2010-senasa-servicio-nacional-de-sanidad-y-calidad-agroalimentaria Para establecer la presencia efectiva de cada activo a nivel comercial, se consultó a los comercios regionales, entre los cuales agradecemos a los del siguiente listado. EEA Alto Valle Fil: De Rossi, Rafael. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle. Agencia de Extensión Rural Río Colorado; Argentina Fil: Cichón. Liliana Isabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentina Fil: Ziaurriz, Sergio Adrián. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle. Agencia de Extensión Rural Villa Regina; Argentina Fil: Colodner, Adrián Darío Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentina Fil: Montenegro, Maricel. Cooperativa de Transformación de Río Colorado; Argentina

Helicoverpa armigera (Hub.) is a destructive pest of the tomato (Lycopersicon esculentum Mill) crop in Pakistan. Although insecticides are the primary management strategy used to control H. armigera, most of them are not effective due to considerable toxic residual effects on the fruits. Nonetheless, H. armigera is rapidly evolving resistance against the available pesticides for its management. This situation calls upon the need of alternative management options against the pest. Different plant extracts have been suggested as a viable, environment-friendly option for plant protection with minimal side effects. Furthermore, the plant extracts could also manage the insect species evolving resistance against pesticides. This study evaluated the efficacy of different plant extracts (i.e., Neem seed, turmeric, garlic and marsh pepper) against H. armigera. Furthermore, the impact of the plant extracts on growth and yield of tomato crop was also tested under field conditions. The results revealed that all plant extracts resulted in higher mortality of H. armigera compared to control. Similarly, the highest plant height was observed for the plants treated with the plant extracts compared to untreated plants. Moreover, the highest tomato yield was observed in plants treated with plant extracts, especially with neem seed (21.013 kg/plot) followed by pepper extract (19.25 kg/plot), and garlic extract 18.4 kg/plot) compared to the untreated plants (8.9 kg/plot). It is concluded that plant extracts can be used as eco-friendly approaches for improving tomato yield and resistance management of H. armigera.

[ES] El objetivo del presente Trabajo de Final de Máster es la búsqueda de la optimización en la gestión de redes de riego, tanto desde el punto de vista del consumo hídrico para regadío como del consumo energético para el funcionamiento de la red. Para ello, se analiza y estudia un caso concreto, el de la Comunidad de Regantes (CC.RR.) del Estepar, perteneciente al Término Municipal de Carlet. Además, se buscará cuantificar la energía recuperable en ciertos puntos de la instalación bajo diversas hipótesis de funcionamiento empleando bombas actuando como turbinas (Pump As a Turbine, PAT). En este contexto, la CC.RR. gestiona el aporte hídrico de aproximadamente 400 hectáreas de cultivos frutales, fundamentalmente cítricos y caquis, para lo cuál cuenta con todas las infraestructuras requeridas para su funcionamiento, destacando: dos balsas de regulación, dos cabezales de riego, un centenar de hidrantes multiusuario componiendo 3 subredes de riego, dos elementos de impulsión (una desde el canal Júcar-Túria y otra desde un pozo), conducciones a presión y elementos de control, regulación y automatización. Además, la topografía de la zona es variable lo que favorece la generación de sobrepresiones en la red recuperables, la dominancia de dos cultivos homogeneiza la demanda y, por ende, la organización del riego a lo largo del año. Para llevar a cabo el estudio, se emplearán aplicaciones informáticas que permitan recopilar la información referente a la topografía de las parcelas y la red en cuestión, destacando el programa de visualización y edición geográfica QGis y el programa de análisis de redes Epanet 2.0. Conocidas las condiciones actuales, se propondrán diferentes hipótesis de funcionamiento de la red de riego, para cada una de las cuales se estudiará la posibilidad de introducir las PAT para cuantificar la posible energía recuperable, manteniendo unas condiciones óptimas de funcionamiento. Finalmente, se aportarán una serie de medidas de mejora y ahorro energético para la futura gestión de la CC.RR., relacionadas con el manejo de la instalación, así como con la optimización de las tarifas eléctricas. Todo ello permitirá concluir sobre la capacidad de mejora de la CC.RR. en el manejo y gestión del regadío, mostrando la viabilidad de las PAT como tecnología innovadora en redes de gran calibre para el ahorro energético y económico., [EN] The aim of this Master's thesis is the search for efficiency in the management of irrigation networks, both from the point of view of water consumption for irrigation and energy consumption and for the operation of the network. To this end, a specific case is analysed and studied. Specifically, the Water Use Association (CC.RR.) of Estepar, belonging to the Municipal District of Carlet (Valencia, Spain). In addition, the aim is to quantify the energy recovery at certain points of the installation under different operating hypotheses using pumps acting as turbines (PAT). In this context, the CC.RR. manages the water supply for approximately 400 hectares of fruit crops, mainly citrus and persimmon, for which it has all the infrastructures required for its operation, including: two regulation reservoirs, two irrigation heads, a hundred multi-user hydrants making up 3 irrigation sub-networks, two impulsion elements (one from the Júcar-Túria canal and the other from a well), pressure pipes and control, regulation and automation elements. In addition, the topography of the area is variable, which facilitates the generation of recoverable overpressures in the network. Finally, the dominance of two crops homogenises the demand, therefore the organisation of irrigation throughout the year too. To carry out the study, computer applications will be used to compile information on the topography of the plots and the network, particularly the QGis geographic visualisation and editing programme and the Epanet 2.0 network analysis programme. Once the current conditions are known, different operating hypotheses for the irrigation network will be proposed, for each of which the possibility of introducing PATs will be studied to quantify the possible energy recovery, maintaining optimal operating conditions. Finally, a list of improvements and energy saving measures will be provided for the future management of the CC.RR., related to the management of the installation, as well as for the optimisation of electricity tariffs. All of this will allow us to conclude on the capacity for improvement of the CC.RR. in the management of irrigation, showing the viability of the PAT as an innovative technology in large-scale networks for energy and economic savings.

El fósforo (P) es considerado un recurso no renovable del suelo y su contenido depende de la naturaleza del material originario y del manejo realizado por el hombre. En un relevamiento realizado en el Alto Valle se observó que cerca del 40 % de las muestras de suelo eran deficitarias en P ya que contenían menos del 10 ppm según método Olsen (Aruani & Sánchez, 2003). Por otra parte, suelos con una buena provisión de fósforo en la actualidad, pueden volverse deficitarios, si no se repone la extracción por parte de las cosechas mediante la aplicación de fertilizantes o abonos. EEA Alto Valle Fil: Curetti, Mariela. Instituto Nacional Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentina Fil: De Rossi, Rafael Pablo. Instituto Nacional Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle. Agencia De Extensión Rural Río Colorado; Argentina

Banana is a staple food and a major export commodity in the tropics. However, banana production systems are affected by the plant-soil relationships, where properties such as quality and quantity of soil organic matter play an important role in the dynamics of soil physical properties. In order to evaluate the effect of the soil organic carbon (SOC) content and its distribution in the water-stable of soil aggregates (WAS), and the physical fractions of the macro-organic matter, a study was conducted in lacustrine soils under Banana cv. ʻGrand Nainʼ in Venezuela. Soil sampling was carried out in two batches differentiated by their textural class and crop production. A completely randomized design under a directed random sampling technique was carried out. In each condition, 12 composite samples were taken at depths 0–5 and 5–10 cm, respectively. WAS were separated into micro (< 250 μm) and macroaggregates (> 250 μm). Also, physical fractionation by size-density of the macro-organic matter into light (LF), intermediate (IF), and heavy (HF) fraction using a silica gel solution, and SOC, were determined and correlated with banana yield and other agronomic traits. A major proportion of aggregates > 250 μm were found in both conditions and depths. Organic Carbon within soil aggregates ranged between 29.7 and 35.3 g kg-1. The HF was superior to IF and LF; however, its C content was higher in the LF. The results allow inferring that the stability conferred to these soils is primarily associated with the presence of the snail, which shares the same size as the aggregates studied. High yields are associated with high C content in stable aggregates, as well as in the most labile fractions of macro-organic matter. These results highlight the importance of the use of organic fertilizers less recalcitrant as a strategy for sustainable management of banana cultivation.

In this study, High throughput sequencing was used to analyze the effects of different vegetable rotations on the rhizosphere bacterial diversity and community structure in a substrate that was used for continuous tomato cropping (CK). The vegetable rotations tested were cabbage/tomato (B), kidney bean/tomato (D), and celery/tomato (Q). The results revealed that the substrate bacterial diversity and richness of each crop rotation were higher than those of CK. The highest bacterial diversity was found in the B substrate, followed by the Q and D substrates. Further comparison showed that the rhizosphere bacterial community structure of Q substrate was significantly different to that of CK. Compared with the CK, the Q substrate had a significantly higher relative abundance of several dominant microflora, such as Acidobacteria, Chloroflexi, and Firmicutes. Additionally, the Q rotation significantly increased the abundance of beneficial bacteria, such as Actinobacteria_unclassified and Anaerolineaceae_unclassified. A redundancy analysis showed that Most dominant bacteria correlated positively with the substrate pH, total N, and alkali-hydrolyzable N but negatively with the available P, available K, total P, total K, and organic matter contents and substrate EC. The substrates after crop rotation improved the growth and physiological condition of the subsequent tomato plants, among which those from the Q rotation performed the best. Therefore, celery rotation not only increased the richness and diversity of bacterial communities in the substrate but also significantly increased the richness of the beneficial bacterial communities, allowing better maintenance of the substrate microenvironment for the healthy growth of crops.

Farm workers are exposed to high risk of heat-related illness, especially when their jobs require working outside at a fast pace during hot days. Climate change has increased the number of days with high temperatures, and thereby the amount of time that farm workers are likely exposed to extreme heat. To better understand how high heat exposure affects farm workers, this study investigates how crop workers respond to heat exposure and estimates the effects of different pay and work arrangements on workers’ responses to heat exposure. We explore, specifically, whether piece-rate arrangements increase workers’ effort during periods with high heat exposure compared to workers paid by hourly wages. We use observational data from detailed measurements of localized heat exposure and individual workers’ effort in the field. First, these results show workers adjust their effort in response to heat exposure when the heat exposure level changes. Second, piece-rate arrangements increase workers’ effort during work shifts. Third, piece-rate arrangements allow workers to modify their effort more easily during different heat exposure levels. When facing low levels of heat exposure, workers who were paid by piece-rate arrangements exert a higher effort than workers paid by hourly wages, up until WBGT is 26.6˚C. When facing high levels of heat exposure (with WBGT exceeding 29.6˚C), workers paid by piece-rate arrangements lower their effort compared to workers paid by hourly wage arrangements.

Flocks of birds may cause major damage to fruit crops in the ripening phase. This problem is addressed by various methods for bird scaring, in many cases, however, the birds become accustomed to the distraction, and the applied scaring procedure loses its purpose. To help eliminate the difficulty, we present a system to detect flocks and to trigger an actuator that will scare the objects only when a flock passes through the monitored space. The actual detection is performed with artificial intelligence utilizing a convolutional neural network. Before teaching the network, we employed videocameras and a differential algorithm to detect all items moving in the vineyard. Such objects revealed in the images were labeled and then used in training, testing, and validating the network. The assessment of the detection algorithm required evaluating the parameters precision, recall, and F1 score. In terms of function, the algorithm is implemented in a module consisting of a microcomputer and a connected videocamera. When a flock is detected, the microcontroller will generate a signal to be wirelessly transmitted to the module, whose task is to trigger the scaring actuator.

The use of adaptable fruit and berry cultivars significantly increases the environmental sustainability of horticulture. In 2014–2018, the assortment of plum in the Urals was evaluated using the parameters of productivity, environmental plasticity and stability under the conditions of Chelyabinsk Province. The analysis of environmental plasticity and stability helped to identify adaptable cultivars of Chinese plum (Prúnus salicina L.): ‘Altayskaya yubileynaya’ and ‘Uralskaya zolotistaya’. Plastic plum cultivars included cv. ‘Uralskaya zolotistaya’ (yield: 5.62 t/ha; bi = 1.10; Si2 = 25.7), ‘Uralskaya serebristaya’ (5.53 t/ha; 1.16; 21.3) and ‘Manchzhurskaya krasavitsa’ (5.53 t/ha; 1.21; 33.9); their productivity varied in accordance with changes in environmental conditions. Intensive-type cultivars with high responsiveness to the improvement of growing conditions (bi significantly higher than 1) were cvs. ‘Uvelskaya’ (5.62 t/ha; 1.46; 26.8) and ‘Krasnoselskaya’ (5.04 t/ha; 1.35; 45.7). Cv. ‘Zhemchuzhina Urala’ (4.65 t/ha; 0.05; 22.8) belongs to the cultivars with low plasticity (the bi value close to zero); it is characterized by a weak response to a change in environmental conditions. Cv. ‘Altayskaya yubileynaya’ produces the highest yield (6.16 t/ha) due to its plasticity (bi = 0.91), but has low stability (Si2 = 102.5), while cv. ‘Shershnevskaya’ secures rather high productivity (5.23 tons per hectare) due to high stability (Si2 = 32.7) and medium responsiveness to changes in environmental conditions (bi = 0.75).

The involvement of the phytohormone ethylene as the main trigger of climacteric fruit ripening is well documented. However, our knowledge regarding the role of ethylene response factor (ERF) transcription factor in the transcriptional regulation of ethylene biosynthesis during fruit ripening remains limited. Here, comprehensive transcriptome analysis and expression profiling revealed 63 ERFs in durian pulps, termed DzERF1–DzERF63, of which 34 exhibited ripening-associated expression patterns at three stages (unripe, midripe, and ripe) during fruit ripening. Hierarchical clustering analysis classified 34 ripening-associated DzERFs into three distinct clades, among which, clade I consisted of downregulated DzERFs and clade III included those upregulated during ripening. Phylogenetic analysis predicted the functions of some DzERFs based on orthologs of previously characterized ERFs. Among downregulated DzERFs, DzERF6 functional prediction revealed its role as a negative regulator of ripening via ethylene biosynthetic gene repression, whereas among upregulated genes, DzERF9 was predicted to positively regulate ethylene biosynthesis. Correlation network analysis of 34 ripening-associated DzERFs with potential target genes revealed a strong negative correlation between DzERF6 and ethylene biosynthetic genes and a strong positive correlation between DzERF9 and ethylene biosynthesis. DzERF6 and DzERF9 showed differential expression patterns in association with different ripening treatments (natural, ethylene-induced, and 1-methylcyclopropene-delayed ripening). DzERF6 was downregulated, whereas DzERF9 was upregulated, during ripening and after ethylene treatment. The auxin-repressed and auxin-induced expression of DzERF6 and DzERF9, respectively, confirmed its dose-dependent responsiveness to exogenous auxin. We suggest ethylene- and auxin-mediated roles of DzERF6 and DzERF9 during fruit ripening, possibly through transcriptional regulation of ethylene biosynthetic genes.

Our knowledge of citrus viruses is largely skewed toward virus pathology in cultivated orchards. Little is known about the virus diversity in wild citrus species. Here, we used a metatranscriptomics approach to characterize the virus diversity in a wild citrus habitat within the proposed center of the origin of citrus plants. We discovered a total of 44 virus isolates that could be classified into species Citrus tristeza virus and putative species citrus associated ampelovirus 1, citrus associated ampelovirus 2, and citrus virus B within the family Closteroviridae, providing important information to explore the factors facilitating outbreaks of citrus viruses and the evolutionary history of the family Closteroviridae. We found that frequent horizontal gene transfer, gene duplication, and alteration of expression strategy have shaped the genome complexity and diversification of the family Closteroviridae. Recombination frequently occurred among distinct Closteroviridae members, thereby facilitating the evolution of Closteroviridae. Given the potential emergence of similar wild-citrus-originated novel viruses as pathogens, the need for surveillance of their pathogenic and epidemiological characteristics is of utmost priority for global citrus production., Author summary Closterovirids are principal plant pathogens for citrus trees and other plants, as they sometimes cause new or re-emerging diseases. However, the closterovirid diversity in natural plant hosts, especially citrus plants, is unclear. Here, we describe three novel species and Citrus tristeza virus within the family Closteroviridae that were sampled from wild citrus trees growing in their natural habitat in southwestern China. The presence of three different taxon classes of the family Closteroviridae indicates the geographical uniqueness of the sampling region for citrus closterovirid evolution. Our analysis shows that frequent horizontal gene transfer, gene duplication, alteration of expression strategy, and recombination have been important evolutionary processes in the diversification of the family Closteroviridae. Our study also shows the significance of natural reserves as potential sources of disease agents endangering cultivated crop plants.

Alphabaculovirus of Chrysodeixis chalcites (ChchNPV-TF1) has been investigated as a useful bioinsecticide against C. chalcites (Esper) (Lepidoptera: Noctuidae) in banana crops. This study investigated the effects of several substances on the persistence of ChchNPV-TF1 under field conditions in the Canary Islands. Natural photoprotective substances, such as moringa, cacao, green tea, benzopurpurine, charcoal, iron dioxide, benzimidazole, kaolinite, and bentonite, were first evaluated under laboratory conditions using a Crosslinker as UV light source at 200 J/cm(2). The photoprotective substances were divided into three groups: low protection (0-8%; kaolinite), intermediate protection (48-62%; green tea, moringa, bentonite and cacao) and high protection (87-100%; charcoal, iron ioxide). Benzopurpurine and benzimidazole did not provide any photoprotective effects. Two of the substances that yielded the best results, 1% cacao and 1% charcoal, were selected for the open-field experiment in a banana plantation. The persistence of ChchNPV-TF1 OBs (occlusion bodies) on leaf surfaces with sunlight exposure was analysed by comparing the initial mortality of 2(nd) instar C. chalcites larvae with the mortality observed at various intervals postapplication. The mortality rates decreased over time in all treatments and were always higher in the UV-protective substance-treated parcels. The 1% charcoal treatment exhibited the highest protection in both the laboratory and field experiments. No specific interference of UV-protective substances on the maximum photochemical efficiency of banana plants was observed under field conditions. This research was supported by Ministerio de Economia y Competitividad-INIA, España-CCAA (2014-2017) (RTA2013-00114-C02) in the form of a grant awarded to ICIA and IMAB, and Ministerio de Ciencia e Innovacion, España-Subvenciones para la formación de personal investigador en agroalimentacion en los centros de investigacion agraria y alimentaria INIA-CCAA FPI INIA) in the form of a grant awarded to TC (CPD 2015-0205).

La drosófila de alas manchadas es una plaga exótica detectada recientemente en nuestro país (Cichón et al., 2015; Santadino et al., 2015) que presenta una importante expansión y puede producir importantes perjuicios en fruta fina, tal como se ha observado en otros países en los que está presente. Se requiere generar información sobre su posible impacto en las distintas ecorregiones argentinas productoras de fruta fina, así como sobre su prevención y manejo. El objetivo de las actividades propuestas es detectar la presencia de Drosophila suzukii en cultivos de interés comercial presentes en diferentes regiones del país, estudiar la fluctuación poblacional del insecto, determinar los niveles de infestación y relevar la presencia de enemigos naturales. EEA San Pedro Fil: Segade, Gonzalo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentina

BackgroundApples in the commercial food chain are harvested up to two weeks before maturity. We explore apple fruit development through the growing season to establish the point at which the features differentiating those cultivars become evident. This is relevant both for the understanding of the growing process and to ensure that any identification and classification tools can be used both on ripened-on-tree and stored fruit. Current literature presents some contradictory findings on apple development, we explored the size development of 12 apple cultivars in the Brogdale National Fruit Collection, UK over two growing seasons.MethodsFruit were sampled at regular time points throughout the growing season and four morphometrics (maximum length, maximum diameter, weight, and centroid size) were collected. These were regressed against growing degree days in order to appropriately describe the growth pattern observed.ResultsAll four morphometrics were adequately described using log-log linear regressions, with adjusted R2estimates ranging from 78.3% (maximum length) to 86.7% (weight). For all four morphometrics, a 10% increase in growing degree days was associated with a 1% increase in the morphometric measurement.DiscussionOur findings refine previous work presenting rapid early growth followed by a plateau in later stages of development and are in disagreement with published expo-linear models. We established that apples harvested for commercial storage purposes, two weeks prior to maturity, showed only a modest decrease in size, demonstrating that size morphometric approaches are appropriate for classification of apples, both ripened-on-tree and stored.

Las variedades que se describen en este informe fueron seleccionadas entre los individuos originados a partir de cruzamientos dirigidos entre distintos cultivares, algunos de uso comercial en la zona, caracterizadas por su buena adaptación a las condiciones regionales de cultivo, y otros sin difusión comercial pero disponibles en la colección de variedades de la EEA San Pedro. EEA San Pedro Fil: Valentini, Gabriel Hugo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentina Fil: Sánchez, Gerardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentina Fil: Aballay, Maximiliano Martín. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentina Fil: Aballay, Maximiliano Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Soria, Florencia Elizabeth. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentina Fil: Soria, Florencia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Chirino, Julián Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentina Fil: Chirino, Julián Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Research Article 1. Fleshy fruit production is becoming more intensive worldwide, but how this affects frugivorous birds is poorly known. In the Mediterranean region, intensive and super-intensive olive orchards are fast expanding, potentially affecting millions of wintering songbirds. Here, we test the idea that intensification may benefit frugivorous birds, at least locally, due to increased fruit availability, while negatively affecting the wider wintering bird community due to intensive management, structural simplification and landscape homogenisation. 2. We estimated olive abundance and surveyed birds in early, mid-and late winter, at traditional, intensive and super-intensive orchards in southern Portugal. We used Hierarchical Modelling of Species Communities to relate species richness, prevalence and abundance to management intensity, winter period, olive availability and landscape context, and evaluated the role of frugivory in modulating observed responses. 3. Olive availability was much higher throughout the winter in more intensive than in traditional orchards, both in trees and on the ground. Frugivorous bird abundance was higher in more intensive orchards, and the most abundant frugivorous species (blackcap, song thrush, robin) were positively affected by olive availability and/or increasing landscape cover by olive orchards, while intensification level had relatively minor effects after accounting for other variables. Non-frugivorous richness and abundance were higher in traditional orchards, and many non-frugivorous species had lower prevalence in more intensive orchards or were negatively affected by landscapes dominated by olive cultivation. 4. Synthesis and applications. While negatively affecting the wider bird community, our results suggest that olive farming intensification can contribute to sustaining large numbers of frugivorous birds in the Mediterranean region. As frugivorous birds are not seen as damaging by olive farmers, there is an opportunity to promote their conservation in intensive and super-intensive orchards, which requires management to increase habitat heterogeneity, and to reduce risks such as mortality associated with mechanical harvest and contamination with pesticide residues. Overall, we recommend that efforts to manage farmland biodiversity should consider the impacts and conservation opportunities of fruit crop intensification info:eu-repo/semantics/publishedVersion