Papers by María Gabriela Cendoya
Revista de la Facultad de Agronomía, Mar 15, 2024
Resumen Sclerotinia sclerotiorum provoca la podredumbre blanca del capítulo (PBC) en girasol, el ... more Resumen Sclerotinia sclerotiorum provoca la podredumbre blanca del capítulo (PBC) en girasol, el cual le ofrece una resistencia de tipo cuantitativa. Consecuentemente, los programas de mejoramiento desarrollaran híbridos moderadamente resistentes a PBC para minimizar los daños potenciales de la enfermedad. La selección de híbridos se efectúa en ensayos multiambientales; no obstante, esta estrategia acarrea un gasto elevado. El objetivo fue hallar la asignación más adecuada de los recursos disponibles, aplicados en los ensayos tendientes a diferenciar híbridos por su nivel de resistencia a la PBC. Por ello en Balcarce se realizaron, durante 3 años, experimentos en el campo bajo un diseño en bloques completos aleatorizados con 3 repeticiones, en los que 37 híbridos fueron inoculados de forma asistida con S. sclerotiorum. A los capítulos enfermos se les midió el período de incubación relativo-PIR y el crecimiento diario relativo de la lesión-CLR (dos componentes de la resistencia parcial a aquella enfermedad). Se estimaron los BLUPs para cada híbrido, empleando todos los recursos disponibles (i.e. 108 plantas/híbrido, resultantes de la combinación 3 años, 3 repeticiones y 12 plantas/parcela), así como para aquellas combinaciones involucrando niveles menores de recursos. La prueba de la diferencia mínima significativa distinguió híbridos según sus BLUPs. Para ambas variables, hubo comportamientos diferenciales con la totalidad y con niveles menores de recursos. Los resultados mostraron la posibilidad de diferenciar, en un mismo ensayo, híbridos por su PIR y CLR ahorrando el 50% de los recursos disponibles al inicio de la experimentación, sin que la evaluación genotípica sea significativamente afectada.
Journal of Arid Environments
African Journal of Agricultural Research, Jun 13, 2013
Neotyphodium coenophialum is an endophyte fungus living in a mutualistic symbiosis with tall fesc... more Neotyphodium coenophialum is an endophyte fungus living in a mutualistic symbiosis with tall fescue [Schedonorus arundinaceus (Schreb.) Dumont]. The endophyte infection affects both health and animal production given the toxicity of the infected plants (fescue toxicosis). Our objective was to determine the incidence of N. coenophialum in some fescue populations placed in both high and low relief, of sites with different aged pastures as well as to evaluate its relationship with soil and vegetation characteristics. Study sites were three and four fields having old and young pastures, respectively, located southeast of Buenos Aires Province, Argentina. In each field, two populations of tall fescue, one from a low relief and the other from a high one, were sampled. Low relief sites were characterized by poor saline-alkaline soil conditions with halophytic vegetation and relatively low ground cover, and high relief ones had better soil conditions dominated by mesophytic grasses and full ground cover. The endophyte incidence across all the evaluated environmental conditions was higher than 95%. No differences were found attributable to soil characteristics and age of pastures, as predicted from the hypothesis of differential abiotic stress tolerance between infected (E+) and non infected (E-) plants. Therefore, it must be provisionally rejected. Alternative hypothesis must consider either effects of preferential herbivory on E-plants, high propagule pressure of infected fescue dispersing from the field margins, and/or higher recruitment rate for E+ than E-seeds from the soil seed bank.
Revista de Investigaciones de la Facultad de Ciencias Agrarias - UNR, 2019
En Argentina existen numerosos estudios aconsejando como utilizar el silo bolsa, sin embargo no s... more En Argentina existen numerosos estudios aconsejando como utilizar el silo bolsa, sin embargo no se ha analizado la manera en que los productores usan realmente esta tecnología. El objetivo de este trabajo es caracterizar el uso del silo bolsa por parte de los productores en la provincia de Buenos Aires, identificar puntos críticos en su uso y señalar necesidades futuras de investigación. El análisis de encuestas a usuarios de silos bolsa indica que más de la mitad de los encuestados no miden las pérdidas de grano y el resto reporta pérdidas menores al 5%. Las principales causas de estas pérdidas son exceso de humedad del grano en el embolsado y roturas en el plástico. Además, las técnicas modernas de monitoreo y sus frecuencias recomendadas se aplican en muy baja proporción. A pesar de estos inconvenientes, la gran mayoría de los productores señalaron que el silo bolsa les permite incrementar los márgenes de la venta de su grano al posibilitarles negociar mejor el precio de venta y...
Journal of Stored Products Research, 2019
The rapid increase of the overall grain production of Argentina resulted with a storage capacity ... more The rapid increase of the overall grain production of Argentina resulted with a storage capacity deficit in permanent structures of 40e50 million tons, and this context favored the rapid adoption of the silo bag technology. Silo bag allows differing grain selling from harvest time, taking advantage of the seasonal price changes and, hence, improving farmers' income. However, storing grain in silo bag could be risky if inadequate planning, handling or monitoring is implemented. Thus, the objective of this article was to develop a prediction model for soybean losses in silo bag storage based on monitoring CO 2 concentration and other sensible variables. During 2013, an experiment was conducted in 13 soybean silo bags placed at farms and grain elevators in Balcarce area, South East of Buenos Aires province, Argentina, since May to December. Grain samples were collected and grain quality was evaluated. Storage variables, such as moisture content and interstitial atmosphere gas composition were also recorded, and at the end of storage, physical grain losses were quantified for each silo bag (kg of spoiled grain not commercialized). The results showed that there was not generalized quality loss in any silo bag, but localized losses were observed. These losses occurred due to water entrance in the silo bag through openings which resulted in spoiled grain from 140 to 4320 kg, representing from 0.07% to 2.16% in a 200 ton silo bag. Next, a correlation to predict grain losses was developed, which considered grain moisture and a predictor related to the CO 2 concentration at the silo bag closing end as independent variables. This correlation explained 73% of the grain losses variability, allowed to model different levels of losses, and was consistent with biological concepts.
Annals of Applied Biology, 2017
The nature of spatial and temporal dynamics of Tomato spotted wilt virus (TSWV) and its vector in... more The nature of spatial and temporal dynamics of Tomato spotted wilt virus (TSWV) and its vector in a potato crop cv. Innovator without insecticide application is analysed. Seed tuber was analysed for the presence of TSWV as a source of initial inoculum. The presence of plants with symptoms of TSWV was evaluated by visual observation and DAS-ELISA analysis to confirm the virus infection. Thrips species were collected from leaves and inflorescences and identified under stereomicroscope. The distribution of symptomatic plants and thrips species was recorded five times at 14 days intervals. The initial seed tuber infection was of 1.1%. Disease incidence was 0% at 29 days after planting (DAP), 0.2% at 43 DAP, 2.2% at 56 DAP, 11.6% at 70 DAP and 14.6% at 84 DAP. The progress of the disease was adequately described by a Logistic model [y = 0.15/(1 + 1205372.93 × exp (−0.22 × DAP))]. Thrips vector species identified as resident in the crop during the whole cycle were Thrips tabaci (n = 423), Frankliniella occidentalis (n = 141) and as occasional species, F. schultzei (n = 34) and F. gemina (n = 5) were found. At 43 and 56 DAP a random distribution pattern was observed and the thrips species found were T. tabaci (n = 188) and F. occidentalis (n = 105). An aggregated pattern was determined at 70 and 84 DAP. Spatial patterns of the disease spread suggest a polycyclic epidemic with TSWV secondary spread in the potato crop. Multiple control measures were deduced from these epidemiological results like virus testing in tubers, removal of external virus infection sources and thrips control.
p.69-78Se caracterizó el régimen de heladas meteorológicas y agrometeorológicas de la localidad d... more p.69-78Se caracterizó el régimen de heladas meteorológicas y agrometeorológicas de la localidad de Balcarce, para el período 1970-1999, en escala anual, mensual y decádica, a través de estadísticos descriptivos y gráficos. Se ajustaron curvas de tendencia en las fechas de primera y última helada a lo largo de los años observándose para la ultima década un atraso en la fecha de primera helada y un adelanto en la fecha de última helada. Este comportamiento trajo aparejada una tendencia creciente (p menor a 0,05) de la longitud del período libre de heladas a través de los años. El número de heladas también disminuyó en el tiempo de forma que la proporción de días con heladas durante el período con heladas no evidenció tendencia (p mayor a 0,05), manteniéndose constante alrededor del 34 por ciento para las agrometeorológicas y alrededor de 19 por ciento para las meteorológicas. Se descartó el efecto de las fases del ENOS como factor de explicación de los cambios en las fechas extremas d...
Crop Breeding and Applied Biotechnology
In breeding for resistance to Fusarium head blight (FHB) there should be precise differentiation ... more In breeding for resistance to Fusarium head blight (FHB) there should be precise differentiation between QTL for resistance and those for spike architecture traits that indirectly affect disease. QTL mapping for FHB Type II resistance and spike architecture traits was carried out in a population of 80 RIL. Three QTL for FHB Type II resistance were identified respectively on chromosomes 2A, 4A and 6D, the last of which is reported here for the first time. The number of florets per spike and per spikelet was associated with FHB Type II resistance but there was not co-localization between QTL for these traits. However, QTL for number of spikelets per spike overlapped with those for FHB Type II resistance on chromosomes 2A and 6D. Spike architecture traits-notably, the number of florets per spike and per spikelet-should be considered in the design of breeding strategies to increase Type II resistance to FHB in bread wheat.
Visión Rural 27 (132) : 19-23 (mayo-junio 2020), Jun 1, 2020
First-year students enrolled in the Agricultural Engineering major come from a wide background in... more First-year students enrolled in the Agricultural Engineering major come from a wide background in terms of geography and education. The aim of this study is to determine if there are differences, due to previous agronomic knowledge, in students' academic performance in the first year course: Introduction to Agricultural Sciences (ICA). General contents of agriculture and livestock in the Argentinean pampas were evaluated in an initial test. Its grades were used as a measure of prior agronomical knowledge and since them groups of students were formed. The cohorts of years 2009 and 2010 were studied. Results for mid terms exams were used as a measure of students' performance in the class. A linear model for each of midterms grades were fitted, considering the effect of year and group as categorical explanatory variables and initial test grade as a covariate. The grades obtained in the first midterm test in 2010 were higher than those of 2009 (p <0.0001). The opposite occurred in the second midterm test 2009: grades were higher than 2010 grades (p <0.0001). Significant differences (α=0.05) in grades between groups were found for both midterm exams. Those with prior agronomic experience obtained higher grades in the midterms exams. Teaching methodology and the importance to identify associated variables to academic success are discussed.
Crop Protection, 2021
Abstract The identification of sources of resistance to Fusarium head blight (FHB) in bread wheat... more Abstract The identification of sources of resistance to Fusarium head blight (FHB) in bread wheat is key to the sustainable management of the disease. An accurate characterization of resistance is critical; however, the experimental designs commonly used disregard germplasm variability in anthesis date (moment of highest disease susceptibility). Here, an accurate methodology for assessing type II resistance to FHB in the field was developed. Individual spikes of 126 RILs were point-inoculated at their optimum moment. The effect of anthesis date and environmental conditions on the prediction of bread wheat lines' performance was established. Anthesis date explained 26% of the total phenotypic variation for Severity at 21 days post-inoculation (dpi). Including this factor in the model increased the accuracy of the best linear unbiased predictors through a reduction of the residual and genotype by environment interaction variances. In addition, the genotypic variance and heritability of FHB severity at 21 dpi were increased. In summary, including the anthesis date effect in the model lead to a more precise and objective characterization of the level of genetic type II resistance to FHB under field conditions.
Journal of Stored Products Research, 2020
Abstract Soybean expeller (SBE) is rich in protein and has a relatively high and variable oil com... more Abstract Soybean expeller (SBE) is rich in protein and has a relatively high and variable oil composition (7–15%). With the increasing use of the SBE for animal nutrition there arose a need for understanding the quality deterioration during storage. The goal of this research was to determine the storability of SBE by developing a model for predicting its equilibrium moisture content (EMC), using the EMC model to determine its safe storage moisture content (SSMC), and by measuring dry matter loss (DML) for SBE incubated at 10 °C and 20 °C for 46 days. Samples of SBE with different residual oil contents were collected and an EMC experiment was carried out to determine the sorption isotherms at 65, 70, 75 and 80% RH; at 10 and 20 °C for samples with 6.2, 9.6 and 15.3% oil content. A second set of samples was used for determining the respiration rate at 20 °C. The Enhanced Halsey model was fitted to the SBE EMC/equilibrium relative humidity (ERH) data and it was established that the residual oil content significantly affected the sorption isotherms. By considering an ERH of 67% or below to be a safe storage condition, the SBE should be stored at or below 12.2% moisture content (m.c.) if the temperature is at or below 20 °C and an the oil content is 7%. However, according to the respiration experiments it would be safe to store SBE up to 16% m.c. (equivalent to 75% ERH). Considering a DML limit of 0.1%, the allowable storage time of SBE at a m.c. lower than 15.4% (ERH of 75%) was at least 46 days. The widely accepted practice of incorporating the gums present in the extracted oil, diluted in water, back into the SBE should be avoided since it increases the m.c. of the product and substantially reduces the allowable storage time.
Euphytica, 2021
Fusarium head blight (FHB) remains a devastating disease in bread wheat (Triticum aestivum L.) an... more Fusarium head blight (FHB) remains a devastating disease in bread wheat (Triticum aestivum L.) and other small grains. Genetic resistance to FHB is a complex trait; in addition to active physiological resistance, plant developmental and morphological traits may indirectly affect disease progression and provide a passive mechanism of resistance. In this study, we investigated the relationship between FHB type II resistance and spike architecture traits in a recombinant inbred line (RIL) population of bread wheat. Disease resistance traits were FHB severity at 21 days post inoculation (dpi) and area under the disease progress curve (AUDPC). Spike architecture traits measured were rachis length, spike density, number of spikelets per spike, florets per spike and florets per spikelet. 2 The RIL population showed significant variation for all traits. Heritability values were moderate to high for FHB severity (0.69) and AUDPC (0.63) and high for the spike architecture traits (0.74-0.92). FHB severity and AUDPC showed a moderate and significant association with the number of florets per spike (r = 0.38 and r = 0.31, respectively) and with the number of florets per spikelet (r = 0.28 and r = 0.27, respectively), reflecting a greater spread of the fungus in spikes with higher floret number. These results suggest that the number of florets per spike and the number of florets per spikelet should be considered in FHB resistance breeding efforts, because selection of lines with higher number of florets could lead to a correlated selection response towards increased FHB levels under field conditions.
ABSTRACT. The grey field slug Deroceras reticulatum has become a pest in no tillage sunflower (He... more ABSTRACT. The grey field slug Deroceras reticulatum has become a pest in no tillage sunflower (Helianthus annuus L.) and soybean (Glycine max L.) crops in the southeast of Buenos Aires province, Argentina. Ground beetles (Coleoptera: Carabidae) are an important component of the arthropod community in agricultural systems and have the potential to reduce pest populations. We tested the predation capacity of the carabid beetle Scarites anthracinus on Deroceras reticulatum individuals of different body mass (10, 20 and 30 mg) and on their eggs, in a controlled laboratory no-choice assay. We also tested its preference for juvenile slugs and the similarly-sized pillbugs (Armadillidium vulgare), under choice conditions. This beetle preyed upon both eggs and juvenile slugs, with the highest consumption rate on 20 mg body mass individuals. While preferring the pillbug during the first 24 h of the choice test, our results suggest that in field conditions, S. anthracinus might be a natural en...
Livestock Science, 2014
Effective management of livestock grazing on heterogeneous subtropical grasslands requires unders... more Effective management of livestock grazing on heterogeneous subtropical grasslands requires understanding the relative role played by factors that determine spatial distribution patterns of animals. We conducted a 2 year study at a site in Corrientes, Argentina, to characterize seasonal patterns of feeding site selection of cattle and sheep co-grazing the same pastures. Livestock were fitted with GPS collars and monitored for 2 weeks in fall, winter, spring, and summer of two consecutive years beginning in 2009. Maps of vegetation units, topography, and facilities were included as layers in a GIS of our study site which, in addition to livestock location data, were used to analyze daily feeding site selection patterns of both livestock species. The k-select multivariate method used for this analysis suggested that 21% of the variation in daily feeding site selection of both cattle and sheep could be explained by vegetation-related variables. Lesser amounts of variation were explained by weather-related variables, topography, and distance to drinking water and shade. In general, cattle tended to select lower elevation sites dominated by taller grasses, whereas sheep tended to select higher elevation sites with steeper slopes dominated by short grasses. Both cattle and sheep appeared to adapt to year-to-year changes in vegetation and rainfall by adjusting their feeding site selection and either expanding or contracting the area explored while grazing in a day. Spatial overlap between species remained low throughout the study. Cattle and sheep appeared to exhibit complementary adaptive feeding strategies at this site. Subtropical grassland areas with heterogeneous vegetation cover could be utilized more efficiently with co-grazing of livestock species with contrasting body size and dietary habits.
Soil and Tillage Research
Agricultural Engineering International: The CIGR Journal, 2015
The adsorption and desorption equilibrium moisture content/equilibrium relative humidity relation... more The adsorption and desorption equilibrium moisture content/equilibrium relative humidity relationships of sunflower seeds with four different oil contents (35.7%, 44.6%, 48.6% and 52.7%) were obtained for temperatures of 8, 15, 25 and 35°C and moisture contents of 6.0%, 8.5%, 11.0%, 13.5%, 16.0% and 18.5%.The goodness of fit of four equilibrium moisture content/equilibrium relative humidity models (Modified Henderson, Modified Chung-Pfost, Modified Halsey and Modified Oswin) were evaluated for each oil content. The Modified Halsey model was the best for predicting equilibrium moisture content/equilibrium relative humidity relationships based on the Akaike Information Criterion, the Bayesian Information Criterion and estimated residual standard derivation. The optimized parameters for the Modified Halsey model are presented for each oil content. Results indicate that the oil content substantially affected the equilibrium moisture content/equilibrium relative humidity relationship. As...
Crop managcment practiccs can have a deep influence on the biological community of agricultura! ... more Crop managcment practiccs can have a deep influence on the biological community of agricultura! systcms. Conservation-tillage practices disturb thc soil only cnough to insert thc secds, and a variety of studies documcnted that conservation-tillage results in more substancial lcaf littcr and large wced community, and tend to host more diverse comrnunities of soil organisms. However, most dangerous species of slugs, as Deroceras reticulatum, are epigea! herbivores that inhabit the soil surface, and have been cited causing damages on severa) crops. Since 1997, it was found in southeast Buenos Aires province, Argentina, on sunflower under not tillage systems. An assumption of our experiment is that Dero ce ra s populations in South America may be genetically distinct because of ditferences in climate or colonization histories. The objective of this study was to determine the growth curve, reproduction, longevity, and survival of D. reticulatum, under controlled laboratory c...
The grey field slug Deroceras reticulatum has become a pest in no tillage sunflower (Helianthus a... more The grey field slug Deroceras reticulatum has become a pest in no tillage sunflower (Helianthus annuus L.) and soybean (Glycine max L.) crops in the southeast of Buenos Aires province, Argentina. Ground beetles (Coleoptera: Carabidae) are an important component of the arthropod community in agricultural systems and have the potential to reduce pest populations. We tested the predation capacity of the carabid beetle Scarites anthracinus on Deroceras reticulatum individuals of different body mass (10, 20 and 30 mg) and on their eggs, in a controlled laboratory no-choice assay. We also tested its preference for juvenile slugs and the similarly-sized pillbugs (Armadillidium vulgare), under choice conditions. This beetle preyed upon both eggs and juvenile slugs, with the highest consumption rate on 20 mg body mass individuals. While preferring the pillbug during the first 24 h of the choice test, our results suggest that in field conditions, S. anthracinus might be a natural enemy of D. ...
Helia
Sunflower is usually affected by white rot (WR), a disease produced by Sclerotinia sclerotiorum. ... more Sunflower is usually affected by white rot (WR), a disease produced by Sclerotinia sclerotiorum. Thus, breeders select WR resistant hybrids by means of field experiments replicated in different environments. The WR selection will be effective when the correlation between the phenotype and the set of genes controlling the trait is high. This study aimed to estimate the relationship between the genotype and phenotype for components of WR partial resistance in hybrids. Also, the genotypic merit of these hybrids is estimated to determine their value in breeding programs. To this end, 37 cultivars were used during three years in Balcarce (southeast of Buenos Aires Province, AR). Plants were inoculated with S. sclerotiorum in their capitula. The WR variables evaluated were the relative incubation period (RIP), the daily lesion growth (DLG) and the relative DLG. By using transformed data, the degree of genetic determination (DGD) reached values of 0.78 (RIP), 0.63 (relative DLG) and 0.35 (...
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Papers by María Gabriela Cendoya