Revista de la Facultad de Ciencias Agrarias
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Diversidad morfológica de poblaciones de maíces nativos (Zea mays L.) del estado de Tabasco, México
Get PDFTraditional farmers keep native or criollo maize (Zea mays L.) in Mexico. The morphological variability of 71 accessions of native maize of the state of Tabasco, Mexico was assessed. Accessions were planted in the 2011 spring-summer cycle in the experimental field of the Universidad Juárez Autónoma de Tabasco, in a completely randomized block design and four replicates. Seventeen morphological characters for plant, ear, cob and grain were evaluated. Significant differences were found in 14 of the 17 characters. A principal components analysis established that 92.3% of the variation was explained by the first three principal components, with the characters ear weight, cob weight and days to female flowering providing the greatest values for diversity. A cluster analysis showed genetic diversity among the accessions, with four groups at a distance of 1.15 units at maximum distance from 1.40 units, following the morphological characteristics of Tuxpeño race was in the 85.9% of the evaluated accessions.En México, los agricultores conservan maíces nativos o criollos (Zea mays L.). En este estudio se caracterizó y clasificó la variabilidad morfológica de 71 colectas de maíces criollos del estado de Tabasco, México. Las colectas se sembraron en el ciclo primavera-verano 2011, en el Campo Agrícola Experimental de la Universidad Juárez Autónoma de Tabasco, bajo un diseño de bloques completos al azar con cuatro repeticiones. Se evaluaron 17 variables morfológicas de planta, mazorca, olote (marlo) y grano; se encontraron diferencias estadísticas en 14 de las 17 variables, el análisis de Componentes Principales (CP) determinó que los primeros tres CP explican el 92,3% de la variación, aportando la mayor variabilidad las variables peso de mazorca, peso de marlo y días a floración femenina. El análisis de conglomerados, detectó diversidad en las colectas, lo que permitió clasificarlas en cuatro grupos a 1,15 unidades de una distancia máxima de 1,40 unidades. Por sus características morfológicas el 85,9% de las colectas se relaciona con la raza Tuxpeño
Siphoninus finitimus Silvestri (Hemiptera: Aleyrodidae), "mosquita blanca del olivo" en Arica-Chile
Get PDFIn this note are given background on the morphometric differences, in the genitalia of adults and the puparium of aleyrodidae populations associated with olive, pear and pomegranate in the region of Arica-Parinacota, Chile. The significant differences (p < 0.01) found in the dimension, and in the morphology of the structures studied between the different populations of whitelfly that attack to olive trees with regard to the pear and the pomegranate allow to establish that in Arica the whitefly of the olive tree is Siphoninus finitimus Silvestri and that S. phillyreae, it is associated with pear and pomegranate.Se ent regan antecedentes sobr e las diferencias morfométricas en distintas estructuras de adultos y del pupoide de las poblaciones de aleyródidos asociados a olivo, peral y granado en la región de Arica- Parinacota, Chile. Las significativas diferencias (p < 0,01) encontradas en las dimensiones y en la morfología de las estructuras estudiadas entre las distintas poblaciones de mosquitas blancas que atacan a olivos respecto del peral y del granado, permiten establecer que en Arica la mosquita blanca del olivo es Siphoninus finitimus Silvestri y que S. phillyreae, está asociada a peral y granado
Adaptación de la poda y ajuste de carga para maximizar los rendimientos de uva de mesa
Get PDFPruning and crop load adjustment were evaluated in order to improve fruit quality and/ or yield. Cluster information was collected under different conditions, and differentiated management was assessed. Clusters and vegetative parameters of table grapes cv. Thompson Seedless, Superior Seedless and Flame Seedless were characterized according to cane bud position. Yield and berry size of cvs. Flame Seedless and Redglobe were evaluated on different crop loads and berry number per cluster according to cluster shape. Clusters from distal buds show better quality than cluster from basal positions. Clusters can be classified early on the season, before crop load adjustment, on conical, spherical or cylindrical; with the two former being the best on yield and quality. In general, up to certain level, increasing crop load and berry number per cluster increase yield with no effect on berry size. Results suggest that best revenue is obtained with pruning and crop load adjustment that take into account cluster shape.La poda y ajuste de carga de uva de mesa fueron evaluados buscando mejorar la calidad de la fruta y/o el rendimiento. Bajo distintas condiciones se recolectó información de los racimos y se evaluaron manejos diferenciados. Los racimos y aspectos vegetativos de uva de mesa variedad Thompson Seedless, Superior Seedless y Flame Seedless fueron caracterizados según ubicación de la yema en el cargador. En las variedades Flame Seedless y Redglobe se evaluó el rendimiento y calibre según nivel de carga y número de bayas por racimo en racimos de distinta forma. Los racimos provenientes de yemas distales presentan mejor calidad que racimos de yemas basales. Los racimos pueden tempranamente, previo al ajuste de carga, ser clasificados en cónicos, esféricos o cilíndricos; los dos primeros son los mejores productiva y cualitativamente. En general, hasta cierto rango, el aumento del nivel de carga y el mayor número de bayas por racimo aumentan el rendimiento sin afectar el tamaño de bayas. Los resultados sugieren que la mejor rentabilidad se obtiene con un manejo de poda y regulación de carga que tome en consideración la forma de los racimos
Determinación de reducción del crecimiento radical (CE50) por una formulación de glifosato utilizando lechuga y trigo como especies bioindicadoras
Get PDFThe objective of this work was to determine a glyphosate formulation effects on the root length reduction (average effective concentration: EC50) using germination bioassays with lettuce and wheat seeds. For lettuce nine decreasing doses/treatments between 1,215 and 0.01215 g a.i.ha-1 (formulated as: N phosphonometyl glycine ammonium salt 40.5 [g e.a. glyphosate 36.9% p/v]) and for wheat five decreasing doses (12.15 and 1.215 g a.i.ha‑1) and their respective negative controls (distilled water) were tested. Bioassays were carried out in Petri boxes with wet filter paper with 3 ml of corresponding solution. Twenty seeds were sowed per box, treatments being distributed in blocks at random with 4 repetitions in germination chamber under alternating light and dark condition at 20°C. All seed average root length and repetition were estimated with a digital caliper. The average germination percentage of treatments and the germination index was also determined. EC50 or doses reducing 50% their radical growth for lettuce and wheat were 6.682 and 9.416 g a.i.ha-1. Plant materials tested resulted sensitive to the different glyphosate doses and they can be used as biological indicators of the specific toxicity.El objetivo fue determinar la concentración efectiva media de reducción del crecimiento radical (CE50), de una formulación del herbicida glifosato mediante bioensayos de germinación con semillas de lechuga y de trigo. Para lechuga se probaron 9 dosis/tratamientos decrecientes entre 1.215 y 0,01215 g i.a.ha-1 (formulado: Sal amónica de la N-Fosfonometil glicina, 40,5 [g e.a. glifosato 36,9% p/v]) y para trigo 5 dosis decrecientes (entre 12,15 y 1,215 g i.a.ha-1) y su respectivo control negativo (agua destilada). Se utilizaron cajas de Petri, con papel de filtro en la base humedecido con 3 ml de la solución correspondiente. Se sembraron 20 semillas por caja, distribuyéndose los tratamientos en bloques al azar con 4 repeticiones, en cámara de crecimiento a 20°C con alternancia de luz y oscuridad. Se midió la longitud radicular de todas las semillas de cada tratamiento con calibre digital. Se determinó el porcentaje de germinación y se calculó el índice de germinación. Las CE50, es decir, las dosis que redujeron en un 50% el crecimiento radical para lechuga y trigo, fueron 6,682 y 9,416 g i.a.ha-1, respectivamente. Los materiales probados resultaron sensibles a distintas dosis de glifosato y por lo tanto pueden utilizarse como indicadores biológicos de toxicidad específica
Responses of Panicum and Brachiaria to irrigation during winter in the Goiás’ Cerrado-Brazil
Get PDFForage production in the Cerrado is based on well-defined seasons: a rainy summer, and a dry winter. To define strategies that minimize the seasonality of forage production, responses in growth and biomass accumulation of five irrigated forages were evaluated during winter. The experimental design was randomized blocks, in a split plot arrangement, with five replicates, five forages in the plots (three of Panicum maximum - Mombasa, Tanzania, and Masai; two of Brachiaria brizantha - piatã and MG5), and five cuts in the subplots made from July to October 2016. Forages were cultivated with centre-pivot irrigation and the water level was defined according to the reference evapotranspiration determined through a Class A pan evaporation method, 0.8 kc, and two-day irrigation shifts. The number of shoots, leaves/tiller, leaves/plant, fresh leaf and stem biomass, dry leaf and stem biomass, fresh leaf mass/fresh stem mass ratio, dry leaf mass/dry stem mass ratio, and biomass accumulated in the five cuts were calculated. Irrigated forage during winter in the Goiás’ Cerrado showed satisfactory growth, reaching a lower plant height between cuts than those reported in the literature. Among the Panicum grasses, Mombasa grass stood out, and MG was superior to piatã grass.
Highlights
The forages Panicum maximum - Mombasa, Tanzania, and Masai -; and Brachiaria brizantha - piatã and MG5 -, presented satisfactory responses in growth and biomass accumulation in an irrigated culture during winter in the Goiás’ Cerrado.
The Mombasa grass stood out among the forage of the genus Panicum and MG5 in the Brachiaria.
The Mombasa and Brachiaria MG5 grasses are recommended for cultivation of irrigated forage during the winter in the Goiás’ Cerrado.Forage production in the Cerrado is based on well-defined seasons: a rainy summer, and a dry winter. To define strategies that minimize the seasonality of forage production, responses in growth and biomass accumulation of five irrigated forages were evaluated during winter. The experimental design was randomized blocks, in a split plot arrangement, with five replicates, five forages in the plots (three of Panicum maximum - Mombasa, Tanzania, and Masai; two of Brachiaria brizantha - piatã and MG5), and five cuts in the subplots made from July to October 2016. Forages were cultivated with centre-pivot irrigation and the water level was defined according to the reference evapotranspiration determined through a Class A pan evaporation method, 0.8 kc, and two-day irrigation shifts. The number of shoots, leaves/tiller, leaves/plant, fresh leaf and stem biomass, dry leaf and stem biomass, fresh leaf mass/fresh stem mass ratio, dry leaf mass/dry stem mass ratio, and biomass accumulated in the five cuts were calculated. Irrigated forage during winter in the Goiás’ Cerrado showed satisfactory growth, reaching a lower plant height between cuts than those reported in the literature. Among the Panicum grasses, Mombasa grass stood out, and MG was superior to piatã grass.
Highlights
The forages Panicum maximum - Mombasa, Tanzania, and Masai -; and Brachiaria brizantha - piatã and MG5 -, presented satisfactory responses in growth and biomass accumulation in an irrigated culture during winter in the Goiás’ Cerrado.
The Mombasa grass stood out among the forage of the genus Panicum and MG5 in the Brachiaria.
The Mombasa and Brachiaria MG5 grasses are recommended for cultivation of irrigated forage during the winter in the Goiás’ Cerrado
Rescue and participatory conservation of Creole goats in the agro-silvopastoral systems of the Mountains of Guerrero, Mexico
Get PDFThe objective was to implement a participatory process involving rescue and conservation of Creole goats in agro-silvopastoral systems, as a development strategy for the indigenous and marginalized region of the Mountains of Guerrero (MG), Mexico. The study focused on the caprine agroecosystem, documenting aspects of goat development and identifying caprine areas in 13 municipalities, zoometrically characterizing 680 goats. One hundred and ten goat producers were interviewed for evaluating farmer perception of goat production. Fifty-seven producers were trained in holistic management, and four producers raised 300 goats in outstanding herds. Data were analyzed using social networks, principal component analysis and correspondence analysis. Two goat agroecosystems were identified: 1) agro-silvopastoralism, with crossbreeding of goat populations and, 2) traditional systems, involving grazing of Creole goats on native vegetation. We identified three types of goats: 1) Mixteco mosaic (61%), 2), Pastoreña (31.8%), and 3) Crossbreeds (7.2%), based on bicoastal diameter, chest depth, body length, thoracic perimeter, height at withers, shoulder point width and liveweight. Smallholder goat farmers in the MG preferred Creole goats for their greater productivity and better environmental adaptation.
Highlights:
Farmer-participatory programs to rescue and conserve the Creole goat breed.
Goats agro-silvopastoral systems with low resource smallholders.
Sustainable utilization of Creole goats.
Goat production systems in the Mexican Mountains.The objective was to implement a participatory process involving rescue and conservation of Creole goats in agro-silvopastoral systems, as a development strategy for the indigenous and marginalized region of the Mountains of Guerrero (MG), Mexico. The study focused on the caprine agroecosystem, documenting aspects of goat development and identifying caprine areas in 13 municipalities, zoometrically characterizing 680 goats. One hundred and ten goat producers were interviewed for evaluating farmer perception of goat production. Fifty-seven producers were trained in holistic management, and four producers raised 300 goats in outstanding herds. Data were analyzed using social networks, principal component analysis and correspondence analysis. Two goat agroecosystems were identified: 1) agro-silvopastoralism, with crossbreeding of goat populations and, 2) traditional systems, involving grazing of Creole goats on native vegetation. We identified three types of goats: 1) Mixteco mosaic (61%), 2), Pastoreña (31.8%), and 3) Crossbreeds (7.2%), based on bicoastal diameter, chest depth, body length, thoracic perimeter, height at withers, shoulder point width and liveweight. Smallholder goat farmers in the MG preferred Creole goats for their greater productivity and better environmental adaptation.
Highlights:
Farmer-participatory programs to rescue and conserve the Creole goat breed.
Goats agro-silvopastoral systems with low resource smallholders.
Sustainable utilization of Creole goats.
Goat production systems in the Mexican Mountains
Modelización de la distribución espacial de Bactericera cockerelli Sulc. (Hemiptera: Triozidae) en Solanum tuberosum L. (Solanales: Solanaceae)
Get PDFThe production of Solanum tuberosum L., Lycopersicum esculentum Mill. and Physalis ixocarpa Brot. (Solanales: Solanaceae) is prone to economic loses because of the presence of Bactericera cockerelli Sulc., which is related to the Purple Top and “zebra chip” diseases, and is also considered a vector of Candidatus Liberibacter solanacearum. The alternatives of control have been inefficient because none of them have considered the spatial behavior of the insect inside the plot. Such behavior would allow focusing the control alternatives, making them more efficient. The purpose on this work was to model the spatial distribution of the eggs, nymphs and adults of B. cockerelli which were obtained in potato field by transects samplings, by using geostatistics tools. The results indicate that the spatial distribution of the populations of eggs, nymphs and adults of B. cockerelli type was aggregated in each sampling date. The cross validation of the semivariograms corroborates the aggregated distribution of eggs, nymphs and adults of B. cockerelli. The generated maps allow observing the aggregated structure of the insect population, letting identify both infested areas and not-infested areas. Spatiotemporal stability was found for the three stages of the insect.La producción de Solanum tuberosum L., Lycopersicum esculentum Mill. y Physalis ixocarpa Brot. (Solanales: Solanaceae) ha sufrido fuertes pérdidas económicas por la presencia de Bactericera cockerelli Sulc. (Hemiptera: Triozidae) al asociarse con las enfermedades punta morada o “zebra chip”, además de ser el transmisor de Candidatus Liberibacter solanacearum. Las alternativas de control utilizadas han carecido de eficacia por desconocer la distribución espacial del insecto dentro de la parcela. Conocer dicho comportamiento permitiría focalizar las alternativas de control, haciéndolas más eficaces. Este trabajo tuvo por objetivo modelizar la distribución espacial de los estadíos de huevo, ninfa y adulto de B. cockerelli obtenidos en muestreos por transectos en un cultivo de papa, utilizando herramientas geoestadísticas. Los resultados indican que la distribución espacial de las poblaciones de huevos, ninfas y adultos de B. cockerelli fue de tipo agregada en cada fecha de muestreo. La validación cruzada de los semivariogramas obtenidos corrobora la distribución agregada en las poblaciones de B. cockerelli. Por su parte, los mapas elaborados permiten observar la estructura agregada de las poblaciones del insecto, permitiendo identificar áreas infestadas y áreas libres. Se encontró estabilidad espacio temporal para los tres estadios del insecto
Evaluación de tolerancia al NaCl en cultivares viníferas y portainjertos híbridos del género Vitis
Get PDFThe purpose of this study was to assess the survival to NaCl in 28 genotypes of the genus Vitis for identifying their degree of salt tolerance. The evaluation included 11 American rootstocks and 17 varieties from Vitis vinifera. Young vines of each genotype were drip-irrigated with a solution of 100 mM of NaCl during 66 days. The day in which 25% of the population had died (1st sample quartile) was calculated, allowing to classify the genotypes according to their salinity tolerance. Three groups of tolerance could be established. First, a sensitive group in which 25% died before the day 30 (3309 Couderc, 161-49 Couderc, Fercal, Freedom, 1103 Paulsen, 99 Richter, SO4, Torrontés Sanjuanino). Second, a moderately tolerant group in which 25% died between the days 30 and 60 (Cereza, Colombard, Criolla Blanca, Criolla Ballista, Palomino, 110 Richter, 140 Ruggeri, Syrah, Torrontés Riojano). Finally, the tolerant group in which 75% survived more than 60 days (101-14 Millardet-Grasset, 196-17 Castel, Criolla Chica, Criolla Sanjuanina, Moscatel de Alejandría, Pedro Giménez). Even in the most tolerant genotypes when the vines grew under salinity, the membranes integrity decreased 17% and the total chlorophyll content decreased 52%.El objetivo fue evaluar la supervivencia al riego con soluciones de NaCl en 28 genotipos del género Vitis para identificar su grado de tolerancia salina. Se estudiaron 11 híbridos de Vitis americanos y 17 variedades de Vitis vinifera. Plantas de 1 y 2 años se regaron durante 66 días con una solución 100 mM de NaCl. Para clasificar las variedades de acuerdo con su grado de tolerancia a la salinidad, se calculó el día en que el 25% de la población había muerto (1er cuartil de la muestra). Se consideraron como genotipos sensibles aquellos en que al menos 25% había muerto antes del día 30 (3309 Couderc, 161-49 Couderc, Fercal, Freedom, 1103 Paulsen, 99 Richter, SO4, Torrontés Sanjuanino), como poco tolerantes cuando al menos 25% murió entre los días 30 y 60 (Cereza, Colombard, Criollas Blanca y Ballista, Palomino, 110 Richter, 140 Ruggeri, Syrah, Torrontés Riojano) y como tolerantes cuando el 75% o menos sobrevivió más de 60 días (101-14 Millardet-Grasset, 196-17 Castel, Criollas Chica y Sanjuanina, Moscatel de Alejandría, Pedro Giménez). Aun en los genotipos más tolerantes cuando las plantas crecieron bajo salinidad, la integridad de membranas celulares se redujo un 17% y el contenido de clorofila total disminuyó un 52%
Actividad biológica de Lonchocarpus guaricensis Pittier en el control de larvas de Tuta absoluta (Meyrick)
Get PDFBiological activity of Lonchocarpus guaricensis Pittier was evaluated using two doses of Tecnona® in the control of larvae of Tuta absoluta (Meyrick), Azapa Valley, Chile, by a spray on potted tomato plants cv. Naomi, randomly placed in a greenhouse within a nursery. Weeks prior to spraying, the pots were artificially infested with adults of phytophagous to obtain larvae in the leaflets. The evaluated treatments were the following ones: T1 (0.21 g AI of L. guaricensis·L-1), T2 (0.43 g AI of L. guaricensis·L-1), T3 (positive control based on spinosad 0.048 g AI·L-1) and T0 (negative control based on well water). According to the cumulative mortality percentage of larvae counted at 24, 48, 120 hours and 9th day post application, there was no statistical differences between T0 and T1 treatments, in turn, T2 reaches an average of 53.05% mortality not differing from T3 that achieves 73.9%. We conclude that the experimental dose of L. guaricensis 0.43 g AI∙L- 1 can be an attractive alternative for use in Integrated Pest Management of the tomato crop in the Azapa Valley.
La actividad biológica de Lonchocarpus guaricensis Pittier fue evaluada utilizando dos dosis de Tecnona® en el control de larvas de Tuta absoluta (Meyrick), Valle de Azapa, Chile, mediante una pulverización sobre plantas de tomate cv. Naomi en macetas, ubicadas aleatoriamente en un invernáculo dentro de un vivero. Semanas previas a la pulverización, las macetas se infestaron artificialmente con adultos del fitófago para obtener larvas en los foliolos. Los tratamientos evaluados fueron los siguientes: T1 (0,21 g de IA de L. guaricensis·L-1), T2 (0,43 g de IA de L. guaricensis·L-1), T3 (control positivo a base de spinosad 0,048 g de IA·L-1) y T0 (control negativo a base de agua de pozo). De acuerdo con el porcentaje de mortalidad acumulada de larvas contabilizadas a las 24, 48, 120 horas y 9no día post aplicación, no hay diferencias estadísticas entre los tratamientos T0 y T1, a su vez, T2 alcanza una media de 53,05% de mortalidad, no diferenciándose de T3 que logra un 73,9%. Se concluye que la dosis experimental L. guaricensis de 0,43 g de IA∙ L-1 puede constituir una alternativa interesante de utilizar en el Manejo Integrado de Plagas del cultivo de tomate en el Valle de Azapa
Effect of forage aqueous extracts on Glycine max L. Merr., Zea mays L. and Bidens pilosa L.
Get PDFThe aim of the present study was to investigate the potential allelopathic effects of isolated or intercropped aqueous forage extracts on the physiological performance of soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) seeds, as well as their phytotoxicity to the weed species Bidens pilosa L. Aqueous extracts were prepared at a concentration of 5%, and the tests with soy and corn were conducted by wetting the germination papers with different treatments and performing procedures within the standards of the Brazilian Rules of Seed Analysis. Tests with the cover plant extracts on the seeds of B. pilosa used BOD-type repetitions. Fifty weed seeds were placed in a gerbox with filter paper moistened with the different treatments with five repetitions. Distilled water was used as the control in all tests. Extracts of Avena strigosa Schreb and Raphanus sativus L. (radish), cultivated individually and in combination, increased the seed germination percentage (%G) and the length of soybean seedlings. Similarly, extracts of Pennisetum glaucum (L.) R.Br and Crotalaria spectabilis Roth, in individual and combined cultivation, provided gains in corn %G. Furthermore, all tested extracts suppressed germination and decreased the speed of the germination index of the hairy beggarticks when compared to the control, with the radish extract showing the greater reduction effect on the %G of the weed plant B. pilosa.
Highlights:
The use of Crotalaria as a cover crop has a positive effect on the initial growth of corn.
The use of black oat and forage radish intercropped had the potential to increase soybean yield.
The use of cover crops contributes to the integrated management of weeds.
The choice of cover plant is important for the success of crop rotation.The aim of the present study was to investigate the potential allelopathic effects of isolated or intercropped aqueous forage extracts on the physiological performance of soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) seeds, as well as their phytotoxicity to the weed species Bidens pilosa L. Aqueous extracts were prepared at a concentration of 5%, and the tests with soy and corn were conducted by wetting the germination papers with different treatments and performing procedures within the standards of the Brazilian Rules of Seed Analysis. Tests with the cover plant extracts on the seeds of B. pilosa used BOD-type repetitions. Fifty weed seeds were placed in a gerbox with filter paper moistened with the different treatments with five repetitions. Distilled water was used as the control in all tests. Extracts of Avena strigosa Schreb and Raphanus sativus L. (radish), cultivated individually and in combination, increased the seed germination percentage (%G) and the length of soybean seedlings. Similarly, extracts of Pennisetum glaucum (L.) R.Br and Crotalaria spectabilis Roth, in individual and combined cultivation, provided gains in corn %G. Furthermore, all tested extracts suppressed germination and decreased the speed of the germination index of the hairy beggarticks when compared to the control, with the radish extract showing the greater reduction effect on the %G of the weed plant B. pilosa.
Highlights:
The use of Crotalaria as a cover crop has a positive effect on the initial growth of corn.
The use of black oat and forage radish intercropped had the potential to increase soybean yield.
The use of cover crops contributes to the integrated management of weeds.
The choice of cover plant is important for the success of crop rotation