Implementation of a low-cost crop detection prototype for selective spraying in greenhouses     

Francisco?C.?PáezEmail author  Víctor?J.?Rincón  Julián?Sánchez-Hermosilla  Milagros?Fernández 《Precision Agriculture》2017,18(6):1011-1023

During phytosanitary treatments aimed at minimizing product losses, selective spraying systems can be employed. These systems consist of a group of detection–action devices which manage the spraying. In this work, the technical feasibility of a low-cost ultrasound detection system prototype has been assessed for pesticide spray application on greenhouse crops. The prototype is based on a commercially-available car parking assistance system, which has been modified to amplify the signal and activate an electro-valve for spray control. This system was fitted into a self-propelled machine with two vertical spray booms. A laboratory test was carried out to evaluate the system limitations (detection range, response time, optimal sensor location); and once the feasibility of the system was known, a field test was conducted. Inside the greenhouse, the same parameters were determined for canopy presence. The system’s capacity to start and stop spraying at the beginnings and ends of the crop lines was also analysed. In addition, the minimum crop line surface with no plant mass that triggers system activation was determined. The results show that the detection range was 0–0.4 m with an average response time of 1.67 s. Based on these parameters, the optimal sensor location was determined for the different forward velocities. In conclusion, the results show that this system is suitable for plant detection at a forward speed of 0.9 m s^?1, allowing growers to stop spraying automatically at the ends of the crop lines and where plant mass absence is greater than 1.0 lineal meter.  相似文献   

Vineyard zone delineation by cluster classification based on annual grape and vine characteristics     

Ana?Belén?González-FernándezEmail author  José?Ramón?Rodríguez-Pérez  Enoc?Sanz?Ablanedo  Celestino?Ordo?ez 《Precision Agriculture》2017,18(4):525-573

This study describes a method for vineyard zone delineation based on spatial interpolation of data on annual monitoring of grape and vine growth from 2007 to 2012 for four commercial vines (Cabernet Sauvignon, Mencía, Merlot and Tempranillo) located in the Bierzo Denomination of Origen (NW Spain). A sampled grid of 20 × 29 m (14 vines/ha) was defined for each vineyard and data were collected for ten soil, six grape composition, three grape production and five vine vigour variables. Continuous maps of each variable were created by spatial interpolation from the sampled points. Several zone delineations were obtained by clustering—using the iterative self-organizing data analysis (ISODATA) algorithm—according to different combinations of the studied variables. The resulting zone delineations were analysed (ANOVA) in order to determine whether the variables in the two cluster classifications for two or three zones were statistically different from each other. The selected delineation was the cluster that included total soluble solids, titratable acidity, total phenolic content, pH, mean cluster weight and length of the internode in two zones. The results point to the feasibility of this approach to vineyard zone delineation. Further research is necessary to confirm the effectiveness of this approach for other locations and evaluate the usefulness of introducing new grape and vine variables.  相似文献   

Cloud-based monitoring system for lysimetric and agroclimatic data     

C. Jiménez-Carvajal  A. J. García-Bañón  J. A. Vera-Repullo  M. Jiménez-Buendía  L. Ruiz-Peñalver  J. M. Molina-Martínez 《Precision Agriculture》2017,18(6):1069-1084

The availability of irrigation water is one of the main concerns in Mediterranean agriculture. For this reason, it is so important to accurately determine the water needs of the crop in order to optimize the use of scarce water resources. This paper presents the design and operation validation of an agroclimatic data acquisition system composed of a set of wireless nodes with different functionalities to ascertain irrigation requirements based on weather and lysimetric data. These nodes were based on a common single-board computer to which, depending on the required features, additional hardware components were added. A comparative study of the different single-board computers available in the market was conducted and the Raspberry Pi device was selected due its high performance to cost ratio. With this philosophy, the design of two types of nodes was proposed: climate nodes and lysimetric nodes. Software drivers were developed for both to perform data acquisition and to send the measurements through a mobile network to an application hosted in the cloud. This application managed the storage of the data in a structured-relational database. The required interfaces were programmed to allow the user to view historical and real-time data, as well as configure additional parameters of the nodes related to the crop, geographical location and so on. This cloud application is accessible from any computer or mobile device with an internet connection. All the software tools and hardware platforms were low-cost and open source. Various performance tests were carried out both in the laboratory and in the field, obtaining evapotranspiration measurements consistent with the reference evapotranspiration calculated from data of the climate node.  相似文献   

RNAseq analysis reveals the role of secondary metabolism in the response of URS 21, a race‐nonspecific resistant cultivar,to crown rust          下载免费PDF全文

A. de A. Figueiró  J. L. Gonzalez‐Hernandez  M. T. Pacheco  R. N. Reese  G. L. de Morais  F. Guzman  P. Swaminathan  C. A. Delatorre 《Plant pathology》2017,66(5):702-712

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Geographical distribution and first molecular detection of an <Emphasis Type="Italic">Emaravirus,High Plains wheat mosaic virus</Emphasis>, in Argentina     

Vanina Alemandri  María Fernanda Mattio  Sandra Mónica Rodriguez  Graciela Truol 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(3):743-750

High Plains wheat mosaic virus (HPWMoV) has recently been assigned to genus Emaravirus and is the causal agent of High Plains disease. In this work the geographical distribution and first molecular detection of HPWMoV in Argentina are reported. The virus was detected in six provinces and nine hosts, including wheat, corn, oat and barley, as well as weeds, which play an important role in the epidemiology of this disease. Molecular and phylogenetic analyses of a portion of RNA3 nucleoprotein gene sequence showed that five HPWMoV isolates from different wheat growing regions of Argentina were identical, and suggest a single introduction of HPWMoV to this country, possibly through corn seeds. To the best of our knowledge, this is the first molecular detection of HPWMoV in South America. These results highlight the importance of certification of viruses-free cereal seeds and strict controls for material transfer between different countries to prevent the entry not only of new pathogens but also of new variants or strain at sites where the pest has already been detected.  相似文献   

Contribution of <Emphasis Type="Italic">Rosellinia necatrix</Emphasis> toxins to avocado white root rot     

I. Arjona-Girona  T. Ariza-Fernández  C. J. López-Herrera 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(1):109-117

By transversely cutting infected avocado plant stems and using PCR techniques on avocado leaves, two experiments were carried out to determine whether Rosellinia necatrix can invade avocado vascular tissues. We were unable to detect the pathogen in either stems or leaves in either experiment, so we concluded that R. necatrix does not invade the vascular system of the plant. Additionally, the toxins produced by the pathogen were also studied to determine whether such toxins could contribute to the wilting and death of avocado plants infected by R. necatrix, having an effect on avocado leaves, where they can hinder the photosynthetic process. First, we isolated and identified the toxins cytochalasin E and rosnecatrone from filtrates of six R. necatrix isolates. Second, we tried to detect cytochalasin E in sap and leaves from infected avocado plants, and it was not detected at the minimum level of 50 μg/kg in leaves or 25 μg/kg on sap. Finally, we observed changes in fluorescence emitted by the avocado leaf surface (to detect photosynthetic efficiency) after inoculating avocado plants with this toxin. Fluorescence was higher in the leaves of plants immersed in toxin solution after 4 and 8 days, but not after longer periods of time. In this work, we demonstrated that although R. necatrix is not a fungus that invades the vascular system, its toxins are probably involved in the wilting and death of infected avocado plants, decreasing the efficiency of photosynthesis.  相似文献   

Molecular and biological characterization of an isolate of <Emphasis Type="Italic">Tomato mottle mosaic virus</Emphasis> (ToMMV) infecting tomato and other experimental hosts in eastern Spain     

S. Ambrós  F. Martínez  P. Ivars  C. Hernández  F. de la Iglesia  S. F. Elena 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(2):261-269

Fusarium Head Blight is a major disease of wheat and an important contributor to the reduced cultivation of wheat in South Africa, where the crop often is grown under irrigation. We collected Fusarium isolates from 860 Fusarium Head Blight-infected wheat heads in seven irrigated wheat-growing areas of South Africa. Six Fusarium species, i.e., F. chlamydosporum, F. crookwellense, F. culmorum, F. equiseti, F. graminearum and F. semitectum were recovered, three of which, i.e., F. chlamydosporum, F. equiseti and F. semitectum, were not previously associated with Fusarium Head Blight in South Africa. Fusarium graminearum occurred at high frequencies at all seven locations. Based on polymerase chain reaction (PCR) assays of diagnostic sequences, more isolates were predicted to produce deoxynivalenol than nivalenol. Fusarium graminearum (sensu lato) appears to be the primary causal agent of Fusarium Head Blight in irrigated wheat in South Africa, which may not be the case for wheat cultivated under rain-fed conditions. Rotations of irrigated wheat with other graminaceous crops and maize could increase fungal inoculum and disease pressure. The establishment of Fusarium Head Blight in the irrigated wheat region of the country means that resistant lines and alternative agronomic practices are needed to limit disease severity, yield losses and mycotoxin contamination.  相似文献   

Local infection associated with vascular bundles: the colonization of coconut palm leaflets by two <Emphasis Type="Italic">Camarotella</Emphasis> species     

Kelly Lana Araújo  Silvaldo Felipe da Silveira  Vicente Mussi-Dias  Juan Manuel Anda Rocabado  Flavio Costa Miguens 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(2):413-422

Two Camarotella (Phyllachoraceae) species, C. torrendiella and C. acrocomiae are the causative agents of small (SV) and large verrucosis (LV), respectively, which are important diseases affecting Brazilian coconut palms. The small verrucosis produces necrotic lesions in coconut palm leaflets, whereas LV just produces chlorosis. Semi-thin sections of asymptomatic leaflets and of leaves presenting stromata in different development stages were compared through light microscopy in order to characterize the colonization process of these two coconut palm verrucosis agents. Camarotella torrendiella initially colonized the adaxial epidermal cells and the cells underlying the epidermis close to the vascular bundles. In latter colonization stages, the hyphae of C. torrendiella remained limited to the underlying necrotic tissue adjacent to the mature stromata, mostly in the intracellular spaces and in the collapsing cells of necrotized tissues around the vascular bundles. This species does not colonize intracellular intact fiber cells, xylem vessels or phloem sieve tube elements. In contrast, C. acrocomiae presented a typical biotrophic parasitism model such as that of some gramineous Phyllachora spp. High densities of C. acrocomiae hyphae were found inside intact sieve tube elements; however, with no evidence of cellular death. The extensive hyphal colonization by C. acrocomiae within sieve tube elements was also observed in tertiary and quaternary bundles, as well as in anastomosing vascular bundles. The dependence of both species on the colonization sites associated with vascular bundles indicates the need for additional studies about these intricate host-pathogen relationships. These studies could be important to define new strategies to control coconut palm verrucosis diseases.  相似文献   

Evaluation of a decision support strategy for the control of powdery mildew,Erysiphe necator (Schw.) Burr., in grapevine in the central region of Chile          下载免费PDF全文

Héctor Valdés‐Gómez  Miguel Araya‐Alman  Carolina Pañitrur‐De la Fuente  Nicolás Verdugo‐Vásquez  Mauricio Lolas  César Acevedo‐Opazo  Christian Gary  Agnès Calonnec 《Pest management science》2017,73(9):1813-1821

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Behaviour of bentazon as influenced by water and tillage management in rice‐growing conditions          下载免费PDF全文

Antonio López‐Piñeiro  David Peña  Ángel Albarrán  Javier Sánchez‐Llerena  José Manuel Rato‐Nunes  María Ángeles Rozas 《Pest management science》2017,73(6):1067-1075

Bentazon is a widely used herbicide in rice agroecosystems that has commonly been found in water resources. To assess how tillage and water regimes affect sorption/desorption, dissipation and leaching of bentazon in Mediterranean rice‐growing conditions, field experiments were carried out using tillage and flooding (TF), tillage and sprinkler irrigation (TS), no‐tillage and sprinkler irrigation (NTS) and long‐term no‐tillage and sprinkler irrigation (NTS7). After 3 years, the K_d values in TS were 2.3, 1.6 and 1.7 times lower than the values in NTS7, NTS and TF respectively. Greater sorption of bentazon was related to higher contents in total organic carbon and, although to a lesser extent, in humic acids and dissolved organic carbon. The persistence of bentazon was significantly greater under anaerobic (half‐life DT₅₀ = 94.1–135 days) than under aerobic (DT₅₀ = 42.4–91.3 days) incubation conditions for all management regimes. Leaching losses of bentazon were reduced from 78 and 74% in TS and TF to 61 and 62% in NTS7 and NTS respectively. The mid‐ and long‐term implementation of sprinkler irrigation in combination with no‐tillage could be considered a management system that is effective at reducing water contamination by bentazon in Mediterranean rice‐growing agroecosystems. © 2017 Society of Chemical Industry  相似文献