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The objective of the article is to estimate the susceptibility to flooding due to river overflow, taking into account average meteorological conditions, based on the study of geomorphological, hydrographic and edaphic variables. The study region is located in the lower section of the Río Negro basin (Argentina). The zoning of the study area, according to its susceptibility to flooding, is the result of a Multicriteria Evaluation (MCE), which is carried out using the weighted sum of variables and based on criteria published in the national and international bibliography. The physical variables analyzed were maximum water extension, land cover, order, drainage and soil texture, topographic slope and geomorphology of the area. These are integrated into a Geographic Information System (GIS). The data used correspond to the databases of the National Geographic Institute of the Argentine Republic (IGN), the National Institute of Agricultural Technology (INTA) and previously published databases. The results categorize 46,7% (1 321,6km2) of the studied territory with low or medium susceptibility. The city of Viedma and the towns of Zanjón de Oyuela, La Boca and Primera Angostura correspond to areas highly susceptible to flooding. It was determined that the occurrence of floods is more significant in areas with topographic slopes of 1% and poor soil drainage. The results show agreement with historical flood events in the area. [ABSTRACT FROM AUTHOR]

Phytophthora infestans is affected by biotic and abiotic factors that can vary its pathogenicity. In the highlands of Mexico, the genetic variability of P. infestans, low temperatures, high relative humidity and light favor its expression and influence the efficacy of the infection. This work analyzed the progress of infection of P. infestans with respect to the expected, observed and simulated during two field cycles in Chapingo, Mexico, with the objective of documenting and quantifying the progress of foliar infection by P. infestans in different lines of Tomato with different levels of resistance. As well as validate a predictive model. With the record of 10 years of meteorological data, five situations were predicted with four to ten cycles of infection from 8 to 13 h each. Compared to the predictions, the observed effect of area under the disease progress curve (AUDPC) and its components (RAUDPC and RaRAUDPC) were significant, with low coefficient of variation. It is concluded that among the expected, observed and simulated scenarios there is a close relationship to predict epidemics of P. infestans. This confirms that LATEBLIGHT is useful for simulating and predicting the late blight epidemic, under Chapingo atmospheric conditions. [ABSTRACT FROM AUTHOR]

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Mango powdery mildew (Erysiphe quercicola) causes up to 90% production losses, so it is necessary to estimate the tolerance to this pathogen of the new germplasm introduced or recently generated to increase the export potential of Mexico. The objective of this study was to determine the response to powdery mildew damage by means of an optimized inoculation technique to induce the disease in attached leaves of 10 new yellow mango cultivars for Mexico. Two inoculation methods were evaluated. The best was to spray conidia at 4.6 x 105 spores mL-1 on the adaxial and abaxial leaves surfaces, at ± 300-450 lux and suspended in polysorbate 20 + surfactant based on ethoxilate alcohols at 2%. The inoculation test showed that the cv. Alphonso was moderately tolerant and Neelum and Fairchild were slightly tolerant. In contrast, Nam Doc Mai, Rosigold, Ataulfo Zafiro, Cotaxtla and Kesar were susceptible and Mallika and Ivory were highly susceptible. The most tolerant cultivars had lower values of incidence, maximum severity, area under the disease progress curve, apparent infection rate and conidia density per cm² of damaged leaf area (LSD, P=0.05). [ABSTRACT FROM AUTHOR]