scholarly journals Climatic drivers of Verticillium dahliae occurrence in Mediterranean olive-growing areas of southern Spain

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0232648
Author(s):  
Juan M. Requena-Mullor ◽  
Jose Manuel García-Garrido ◽  
Pedro Antonio García ◽  
Estefanía Rodríguez
Keyword(s):  
Verticillium Dahliae ◽  
Large Scale ◽  
Climatic Factors ◽  
Irrigation Management ◽  
Temperature Oscillation ◽  
Southern Spain ◽  
Climatic Variables ◽  
Large Scale Field ◽  
Climatic Drivers ◽  
Olive Trees

Verticillium wilt, caused by the soil-borne fungus Verticillium dahliae, is one of the most harmful diseases in Mediterranean olive-growing areas. Although, the effects of both soil temperature and moisture on V. dahliae are well known, there is scant knowledge about what climatic drivers affect the occurrence of the pathogen on a large scale. Here, we investigate what climatic drivers determine V. dahliae occurrence in olive-growing areas in southern Spain. In order to bridge this gap in knowledge, a large-scale field survey was carried out to collect data on the occurrence of V. dahliae in 779 olive groves in Granada province. Forty models based on competing combinations of climatic variables were fitted and evaluated using information-theoretic methods. A model that included a multiplicative combination of seasonal and extreme climatic variables was found to be the most viable one. Isothermality and the seasonal distribution of precipitation were the most important variables influencing the occurrence of the pathogen. The isothermal effect was in turn modulated by the seasonality of rainfall, and this became less negative as seasonality increases. Thus, V. dahliae occurs more frequently in olive-growing areas where the day-night temperature oscillation is lower than the summer-winter one. We also found that irrigation reduced the influence of isothermality on occurrence. Our results demonstrate that long-term compound climatic factors rather than “primary” variables, such as annual trends, can better explain the spatial patterns of V. dahliae occurrence in Mediterranean, southern Spain. One important implication of our study is that appropriate irrigation management, when temperature oscillation approaches optimal conditions for V. dahliae to thrive, may reduce the appearance of symptoms in olive trees.

scholarly journals Climatic drivers of Verticillium dahliae occurrence in Mediterranean olive-growing areas of southern Spain

2020 ◽  
Author(s):  
Juan Miguel Requena-Mullor ◽  
Jose Manuel García-Garrido ◽  
Pedro Antonio García ◽  
Estefanía Rodríguez
Keyword(s):  
Verticillium Dahliae ◽  
Climatic Factors ◽  
Irrigation Management ◽  
Temperature Oscillation ◽  
Landscape Scale ◽  
Southern Spain ◽  
Climatic Variables ◽  
Information Theoretic ◽  
Climatic Drivers ◽  
Olive Trees

AbstractVerticillium wilt, caused by the soil-borne fungus Verticillium dahliae, is one of the most harmful diseases in Mediterranean olive-growing areas. Although, the effects of both soil temperature and moisture on V. dahliae are well known, there is scant knowledge about what climatic drivers affect the occurrence of the pathogen on a landscape scale. Here, we investigate what climatic drivers determine V. dahliae occurrence in olive-growing areas in southern Spain. In order to bridge this gap in knowledge, a landscape-scale field survey was carried out to collect data on the occurrence of V. dahliae in 779 olive groves in Granada province. Forty models based on competing combinations of climatic variables were fitted and evaluated using information-theoretic methods. A model that included a multiplicative combination of seasonal and extreme climatic variables was found to be the most viable one. Isothermality and the seasonal distribution of precipitation were the most important variables influencing the occurrence of the pathogen. The isothermal effect was in turn modulated by the seasonality of rainfall, and this became less negative as seasonality increases. Thus, V. dahliae occurs more frequently in olive-growing areas where the day-night temperature oscillation is lower than the summer-winter one. We also found that irrigation reduced the influence of isothermality on occurrence. Our results demonstrate that long-term “sophisticated” climatic factors rather than “primary” variables, such as annual trends, can better explain the spatial patterns of V. dahliae occurrence in Mediterranean, southern Spain. One important implication of our study is that appropriate irrigation management, when temperature oscillation approaches optimal conditions for V. dahliae to thrive, may reduce the appearance of symptoms in olive trees.

scholarly journals Region-Wide Analysis of Genetic Diversity in Verticillium dahliae Populations Infecting Olive in Southern Spain and Agricultural Factors Influencing the Distribution and Prevalence of Vegetative Compatibility Groups and Pathotypes

2011 ◽  
Vol 101 (3) ◽  
pp. 304-315 ◽  
Author(s):  
Rafael M. Jiménez-Díaz ◽  
Concepción Olivares-García ◽  
Blanca B. Landa ◽  
María del Mar Jiménez-Gasco ◽  
Juan A. Navas-Cortés
Keyword(s):  
Genetic Diversity ◽  
Verticillium Dahliae ◽  
Irrigation Management ◽  
Water Source ◽  
Vegetative Compatibility ◽  
Southern Spain ◽  
Vegetative Compatibility Groups ◽  
Discriminant Model ◽  
Olive Trees ◽  
Log Linear

Severity of Verticillium wilt in olive trees in Andalusia, southern Spain is associated with the spread of a highly virulent, defoliating (D) Verticillium dahliae pathotype of vegetative compatibility group 1A (VCG1A) but the extent of this spread and the diversity of the pathogen population have never been documented. VCG typing of 637 V. dahliae isolates from 433 trees in 65 orchards from five olive-growing provinces in Andalusia indicated that 78.1% were of VCG1A, 19.8% of VCG2A, 0.6% of VCG2B, 1.4% of VCG4B, and one isolate was heterokaryon self-incompatible. A single VCG prevailed among isolates within most orchards but two and three VCGs were identified in 12 and 3 orchards, respectively, with VCG1A+VCG2A occurring in 10 orchards. VCG1A was the predominant VCG in the three most important olive-growing provinces, and was almost as prevalent as VCG2A in another one. Molecular pathotyping of the 637 isolates using specific polymerase chain reaction assays indicated that VCG1A isolates were of the D pathotype whereas isolates of VCG2A, -2B, and -4B were of the less virulent nondefoliating (ND) pathotype. The pathotype of isolates correlated with the disease syndrome affecting sampled trees. Only three (seq1, seq2, and seq4) of the seven known sequences of the V. dahliae-specific 539- or 523-bp amplicon were identified among the 637 isolates. Distribution and prevalence of VCGs and seq sequences among orchards indicated that genetic diversity within olive V. dahliae in Andalusia is higher in provinces where VCG1A is not prevalent. Log-linear analysis revealed that irrigation management, source of irrigation water, source of planting stock, and cropping history of soil were significantly associated with the prevalence of VCG1A compared with that of VCG2A. Multivariate analyses using a selected set of agricultural factors as variables allowed development of a discriminant model for predicting the occurrence of D and ND pathotypes in the area of the study. Blind tests using this model correctly indentified the V. dahliae pathotype occurring in an orchard. The widespread occurrence and high prevalence of VCG1A/D pathotype in Andalusia have strong implications for the management of the disease.

Limited application of irrigation water does not affect the nutritive characteristics of lucerne

2014 ◽  
Vol 54 (10) ◽  
pp. 1635 ◽  
Author(s):  
M. E. Rogers ◽  
A. R. Lawson ◽  
S. Chandra ◽  
K. B. Kelly
Keyword(s):  
Water Supply ◽  
Irrigation Water ◽  
Crude Protein ◽  
Protein Concentration ◽  
Large Scale ◽  
Management Practices ◽  
Irrigation Management ◽  
Irrigation Season ◽  
Large Scale Field ◽  
Limited Application

Lucerne (Medicago sativa) has not been a significant part of the feedbase of the Murray-Dairy Region of Australia. However, under future climate regimes, which are indicating an overall decline in rainfall as well as water available for irrigation of pastures, lucerne is emerging as a potential forage species because of its adaptability, productivity and resilience. A large-scale field experiment was conducted at Tatura, Victoria, Australia, over four years to determine the dry matter (DM) production and nutritive characteristics of lucerne under a range of limiting and non-limiting irrigation management practices. Nine irrigation treatments were imposed that ranged from full irrigation to no irrigation in either a single, or over consecutive, irrigation seasons. Plots were harvested using plant-based criteria over the irrigation season and DM production and nutritive characteristics were determined. DM production generally increased as the total water supply (irrigation plus rainfall plus changes in soil water) increased, with the fully irrigated treatments producing significantly more DM than the treatments where the irrigation water had been restricted. Mean annual DM digestibility concentration was 66% of DM and was not affected by treatment. Similarly, mean crude protein concentration, which was 22% of DM, was also not affected by treatment. There was no consistent effect of restricted irrigation on the neutral detergent fibre concentration of the lucerne plants. These results suggest that in seasons where irrigation is restricted because of limited water supply, the reduction in lucerne productivity is not associated with a penalty in forage nutritive characteristics, with lucerne able to provide sufficient nutrients to form a large proportion of the total diet for a high-producing dairy cow.

Biodata response elaboration: A large-scale field experiment

2010 ◽  
Author(s):  
Julia Levashina ◽  
Frederick P. Morgeson ◽  
Michael A. Campion
Keyword(s):  
Field Experiment ◽  
Large Scale ◽  
Scale Field ◽  
Large Scale Field

Hybrid Combination of GIS,GPS,WSN and GPRS Technology in Modern Digital Agriculture Application

2010 ◽  
Vol 108-111 ◽  
pp. 1158-1163 ◽  
Author(s):  
Peng Cheng Nie ◽  
Di Wu ◽  
Weiong Zhang ◽  
Yan Yang ◽  
Yong He
Keyword(s):  
Large Scale ◽  
Field Application ◽  
Wireless Sensor ◽  
Information Collection ◽  
Scale Field ◽  
Large Scale Field ◽  
Field Information ◽  
Intelligent Management ◽  
Digital Agriculture ◽  
And Control

In order to improve the information management of the modern digital agriculture, combined several modern digital agriculture technologies, namely wireless sensor network (WSN), global positioning system (GPS), geographic information system (GIS) and general packet radio service (GPRS), and applied them to the information collection and intelligent control process of the modern digital agriculture. Combining the advantage of the local multi-channel information collection and the low-power wireless transmission of WSN, the stable and low cost long-distance communication and data transmission ability of GPRS, the high-precision positioning technology of the DGPS positioning and the large-scale field information layer-management technology of GIS, such a hybrid technology combination is applied to the large-scale field information and intelligent management. In this study, wireless sensor network routing nodes are disposed in the sub-area of field. These nodes have GPS receiver modules and the electric control mechanism, and are relative positioned by GPS. They can real-time monitor the field information and control the equipment for the field application. When the GPS position information and other collected field information are measured, the information can be remotely transmitted to PC by GPRS. Then PC can upload the information to the GIS management software. All the field information can be classified into different layers in GIS and shown on the GIS map based on their GPS position. Moreover, we have developed remote control software based on GIS. It can send the control commands through GPRS to the nodes which have control modules; and then we can real-time manage and control the field application. In conclusion, the unattended automatic wireless intelligent technology for the field information collection and control can effectively utilize hardware resources, improve the field information intelligent management and reduce the information and intelligent cost.

scholarly journals Inverse Infiltration Modeling of Dike Covers Made of Dredged Material Using PEST and AMALGAM

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 41
Author(s):  
Tim Jurisch ◽  
Stefan Cantré ◽  
Fokke Saathoff
Keyword(s):  
Large Scale ◽  
Measurement Data ◽  
Fine Grained ◽  
Dredged Materials ◽  
Measurement Results ◽  
Large Scale Field ◽  
Eigenvalue Ratio ◽  
Ill Posed ◽  
Materials Used ◽  
Installation Technology

A variety of studies recently proved the applicability of different dried, fine-grained dredged materials as replacement material for erosion-resistant sea dike covers. In Rostock, Germany, a large-scale field experiment was conducted, in which different dredged materials were tested with regard to installation technology, stability, turf development, infiltration, and erosion resistance. The infiltration experiments to study the development of a seepage line in the dike body showed unexpected measurement results. Due to the high complexity of the problem, standard geo-hydraulic models proved to be unable to analyze these results. Therefore, different methods of inverse infiltration modeling were applied, such as the parameter estimation tool (PEST) and the AMALGAM algorithm. In the paper, the two approaches are compared and discussed. A sensitivity analysis proved the presumption of a non-linear model behavior for the infiltration problem and the Eigenvalue ratio indicates that the dike infiltration is an ill-posed problem. Although this complicates the inverse modeling (e.g., termination in local minima), parameter sets close to an optimum were found with both the PEST and the AMALGAM algorithms. Together with the field measurement data, this information supports the rating of the effective material properties of the applied dredged materials used as dike cover material.

scholarly journals Provenance Trials of the Mexican Spruces in Nursery Conditions: Three Species Endangered by Climatic Variation

2020 ◽  
Vol 3 (1) ◽  
pp. 12
Author(s):  
José Marcos Torres-Valverde ◽  
José Ciro Hernández-Díaz ◽  
Artemio Carrillo-Parra ◽  
Eduardo Mendoza-Maya ◽  
Christian Wehenkel
Keyword(s):  
Cluster Analysis ◽  
Genetic Differentiation ◽  
Local Adaptation ◽  
Quantitative Traits ◽  
Climatic Factors ◽  
Climatic Variation ◽  
Climatic Variables ◽  
Provenance Trials ◽  
Survival And Growth ◽  
Picea Species

The three Mexican spruces’ distributions are fragmented, which could lead to phenological, morphological and genetic differentiation, partially caused by local adaptation. In this study, we examined the effect that climatic variables had on the survival and growth of 5641 Picea seedlings, coming from eight seed provenances of three species and produced in identical nursery conditions. The respective responses of each species and provenance can be considered as a proxy of the genetic differentiation and adaptation of each population. A cluster analysis revealed: (i) significant differences in genetic quantitative traits among the three Picea species and (ii) significant correlations between genetic quantitative traits and climatic factors.

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