Resumen Para evaluar el efecto de la incorporación de L. leucocephala sobre la producción de biomasa y la composición química de P. maximum cv. Tanzania en un sistema silvopastoril, se estableció un experimento en dos praderas, establecidas con P. maximum cv. Tanzania como único cultivo en una de ellas y en la otra asociada con L. leucocephala en un arreglo de pasturas en callejones. En cada pradera fueron colocadas 12 jaulas de exclusión de 1 m3 en un diseño completamente al azar con arreglo factorial 2 x 4, dos sistemas (monocultivo y silvopastoril) y cuatro fechas de corte (28, 56, 84 y 112 d) y tres repeticiones. Se aplicó una fertilización química con Fosfonitrato en cada una de las jaulas de exclusión para ambos tratamientos. Se observó diferencia significativa entre sistemas para las variables altura, cobertura, producción de materia orgánica (kg/ha), producción de proteína cruda (kg/ha) y el porcentaje de FDN, reportando los mejores valores el sistema silvopastoril. Se concluye que el uso de la Leucaena ofrece ventajas importantes si se considera que es capaz de producir alimento de alto valor nutricional para los animales, además, mejora la calidad y cantidad de forraje del sistema.

Abstract To evaluate the effect of L. leucocephala incorporation on P. maximum cv. Tanzania biomass production and chemical composition of in a silvopastoral system, an experiment was established in two grasslands, established with P. maximum cv. Tanzania as the only crop in one of them and in the other, associated with L. leucocephala in an arrangement of pastures in alleys. In each meadow, 12 exclusion cages of 1 m3 were placed in a completely random design with a 2 x 4 factorial arrangement, two systems (monoculture and silvopastoral) and four cutting dates (28, 56, 84 and 112 d) and three repetitions. Chemical fertilization with Phosphonitrate was applied in each of the exclusion cages for both treatments. A significant difference was observed between systems for the variables height, coverage, production of organic matter (kg/ha), production of crude protein (kg/ha) and the percentage of FDN, reporting the best values of the silvopastoral system. It is concluded that the use of Leucaena offers important advantages if we consider its capability for producing food of high nutritional value for animals, as well as it improving the forage quality and quantity of the system.

Abstract Dry matter production (DM) and morphological composition were evaluated according to regrowth age (RA; four, six, and eight weeks) and prairie height (PH) in Pennisetum ciliare cv. H-17, during rainy season (RS) and drought (DS). The variables were total MS (TDM), leaf (LDM), stem (SDM), dead material (DMDM) and PH. A completely randomized design with four repetitions and linear regression analysis was used. During RS, the TDM was similar (p > 0.05) between RA (8342 kg ha-1) and decreased 90% in DS. During RS, there was greater (p < 0.05) LDM at four weeks, while at eight there was greater SDM and DMDM. The SDM and DDM were manifested when the PH was 34 cm and 47 cm, respectively. The RA and PH had a significant effect on the performance and structural behavior of DM in Pennisetum ciliare cv. H-17.

Resumen Se evaluó la producción de materia seca (MS) y composición morfológica en función de la edad de rebrote (ER; cuatro, seis y ocho semanas) y altura de pradera (AP) en Pennisetum ciliare cv. H-17, durante época de lluvias (ELL) y seca (ES). Las variables fueron MS total (MSTT), hoja (MSh), tallo (MSt), material muerto (MSmm) y AP. Se utilizó un diseño completamente al azar con cuatro repeticiones y análisis de regresión lineal. Durante ELL, la MSTT fue similar (p > 0.05) entre ER (8342 kg ha-1) y disminuyó 90% en la ES. Durante ELL, se presentó mayor (p < 0.05) MSh a cuatro semanas, mientras que a ocho se presentó mayor MSt y MSmm. La MSt y MSmm se manifestaron cuando la AP fue de 34 cm y 47 cm, respectivamente. La ER y AP tuvieron efecto significativo en el rendimiento y comportamiento estructural de MS en Pennisetum ciliare cv. H-17.

Este estudo observou a dinâmica populacional dos mosquitos em açude eutrofizado na área rural de Paraíba do Sul, Estado do Rio de Janeiro. Foram realizadas 12 coletas mensais de mosquitos imaturos pelo método da conchada em 9 m de borda, divididos em três postos (P1, P2 e P3), com 3 m de extensão cada. O posto P1 difere por não ter vegetação (capim, mato) na margem, alcançando ou penetrando e promovendo alguma sombra na água. Larvas L3, L4 e pupas foram isoladas para a obtenção dos adultos e identificação. Foram identificados 217 espécimes adultos de quatro espécies, com as seguintes constâncias e frequências: Culex quinquefasciatus (Say, 1823) (83% e 40,6%), Anopheles (Nyssorhynchus) evansae (Brèthes, 1926) (92% e 26,7%), Anopheles (Nyssorhynchus) rangeli (Gabaldon, Cova Garcia e Lopez, 1940) (83% e 14,3%) e Culex nigripalpus (Theobald, 1901) (33% e 18,4%), com maiores frequências nos trimestres nov./dez./jan. (85,7%), maio/jun./jul. (75%), ago./set./out. (29,4%), ago./set./out. (23,5%) e, nos meses dezembro (88,4%), setembro (48,94), (38,3) e agosto (47,62), respectivamente. A presença do Culex quinquefasciatus (40%) e a elevada incidência de Daphinia sp., juntamente com os níveis de Nitrogênio orgânico (0,28 mg/L) e de Fósforo total (0,02 mg/L), indicam a eutrofização do açude. Houve diferença comparando os totais de anofelinos (A. avansae + A. rangeli) com os totais de culicini (C. quinquefasciatus + C. nigripalpis) entre P1 e P2 (χ² = 0,0097), e entre P1 para P3 (χ² = 0,0005), mas não entre P2 e P3 (χ² = 0,2045). A elevada frequência e a constância de C. quinquefasciatus confirmam esta ser uma boa espécie bioindicadora para ambientes eutrofizados e A. evansae apresentou boa potencialidade nesse nível trófico. A vegetação pode influir na dinâmica populacional dos anofelinos também em ambientes eutróficos.

This study observed the mosquito population in a rural eutrophised dam. Larvae of L3 and L4 stages and pupae were dipped out during twelve month collections and the reared to the adult stage for identification. The collections were done along nine metres from the edge of the dam divided in three parts (P1, P2 and P3), each part being 3 m long. P1 did not have vegetation (grass) along its edge,which would reach or sink into the water to promote some shade on the marginal water. A total of 217 adults of four species was identified with the following constancies and frequencies: Culex quinquefasciatus (Say, 1823) (83% and 40.6%), Anopheles (Nyssorhynchus) evansae (Brèthes, 1926) (92% and 26.7%), Anopheles (Nyssorhynchus) rangeli (Gabaldon, Cova Garcia and Lopez, 1940) (83% and 14.3%) and Culex nigripalpus (Theobald, 1901) (33% and 18.4%). C. quinquefasciatus, A. evansae, A. rangeli and C. nigripalpus were more frequent in the quarters Nov./Dec./Jan. (85.7%), May/June/July (75%), Aug./Sept./Oct. (29.4%) and Aug./Sept./Oct. (23.5%) particularly in the months of December (88.4%) Sept.tember (48.94), (38.3) and August (47.62) respectively. The presence of C. quinquefasciatus and the high incidence of Daphinia sp. and also the levels of Organic Nitrogen (0.28 mg/L) and of total Phosphorus (0.02 mg/L) are indications of the eutrophication of the dam. There was a difference regarding the total of Anopheles (A. avansae + A. rangeli) and Culex species (C. quinquefasciatus + C. nigripalpis) between P1 and P2 (χ² = 0.0097), P1 and P3 (χ² = 0.0005), but not between P2 and P3 (χ² = 0.2045).The high C. quinquefasciatus constancy and frequency were confirmed to be a good biological indicator for a eutrophised environment and A. evansae showed a good potential for this environment. Vegetation can be an important factor for anopheline population dynamic also in eutrophic breeding sites.

Zucchini fruits (Cucurbita pepo L.) show high metabolic activity and transpiration rates, and are highly susceptible to mechanical damage during harvest and postharvest. In this study, the effect of storage temperature on water status, cellular integrity and postharvest quality of zucchini were evaluated. Fruits in horticultural maturity stage s were stored 12 d at 10 and 20 °C, and 85 to 87 % relative humidity. Weight loss, relative water content (RWC), water potential (Ψw), osmotic potential (Ψπ), pressure potential (Ψp), and cellular integrity observed through histological studies in fruits, were analyzed. The first sign of wilting ocurred with 6 % of weight loss. Cell tissue plasmolysis occurred between 81 and 82 % of RWC, when Ψp was equal to zero and Ψw and Ψπ were equal to -0.8 MPa. Fruit tissue integrity was affected by the loss of adhesion cells at the endocarp zone which progressed to the pericarp.

El fruto de calabacita (Cucurbita pepo L.) es una hortaliza que presenta elevada actividad metabólica, alta transpiración y sensibilidad a daños mecánicos en postcosecha. En este estudio se evaluó el efecto de la temperatura de almacenamiento en el estado hídrico, la integridad celular y la calidad postcosecha de frutos de calabacita tipo Zucchini cv. 'Raben'. Frutos cosechados en madurez hortícola se almacenaron por 12 d a 10 y 20 °C, y 85 a 87 % de humedad relativa. Se evaluó pérdida de peso, marchitamiento, contenido relativo de agua (CRA), potencial hídrico (Ψw), potencial osmótico (Ψs), potencial de presión (Ψp) e integridad celular mediante un estudio histológico de los frutos. Los primeros síntomas de marchitez del fruto aparecieron cuando hubo 6 % de pérdida de peso. La plasmólisis celular se presentó entre 81 y 82 % de CRA, con un Ψp igual a cero y con Ψw y Ψs iguales a -0.8 MPa. La integridad del tejido se afectó por la pérdida de adhesión de las células de la zona del endocarpio, que luego progresó hacia el epicarpio del fruto.

Predicting the phenology of faba bean is a critical step to designing good crop management practices, as well as to the development of crop models. This article examines the phenological response of faba bean (Vicia faba L.) to different temperature and photoperiod regimes assessed through linear models. Seventeen field-sowing dates were used over a three-year lapse in Lugo, Spain (43°04' N, 7°30' W, 480 m altitude), on which phenological observations were made. The time from emergence to flowering was satisfactorily described using a photothermal model, whereas the rates of progress from sowing to flowering, flowering to first pod and first pod to physiological maturity were satisfactorily modeled using only temperature as independent variable. Basal temperature values ranged between 2.09 and 4.47°C, depending on the phenological subperiod. Base photoperiod was 6.9 h, while the critical photoperiod was 16.2 h.

La predicción de la fenología del haba es un paso crítico para optimizar el manejo de los cultivos, así como para el desarrollo de modelos de cultivos. Este artículo examina la respuesta fenológica del cultivo de haba (Vicia faba L.) a diversos regímenes térmicos y fotoperíodicos evaluada mediante modelos lineales. Se realizaron diecisiete fechas de siembra durante tres años en Lugo, España (43°04' N; 7°30' W; altitud 480 m) en las que se hicieron observaciones fenológicas. El tiempo desde emergencia a floración se describe satisfactoriamente mediante un modelo fototérmico. Las tasas de desarrollo de siembra a emergencia, floración hasta la primera vaina y primera vaina hasta madurez fisiológica fueron modeladas en forma satisfactoria, utilizando solamente la temperatura como variable independiente. Los valores de temperaturas basales variaron entre 2,09 y 4,47°C, dependiendo del subperíodo fenológico. El fotoperíodo base resultó de 6,9 h mientras el fotoperíodo crítico fue de 16,2 h.

The objectives of this investigation were to characterize the quality components of the chickpea fruit, to describe the anatomy of the pod, and to study postharvest technology for increasing the shelf life of the fruits. Green chickpeas cv. 'Blanco Sinaloa' were harvested; proximate analysis, minerals, pH, acidity and total soluble solids were separately analyzed in both pods and seeds. Histological evaluations were done on pods at 0, 6 and 12 days. Four lots of fruits were treated, each with 1) 0.5 μl·L-1 and 2) 1.0 μl·L-1 of 1-methylcyclopropene (1-MCP), 3) sprayed water at 65 °C, and 4) control. Samples were stored for 12 days at 10 °C using PET containers. Evaluations of weight loss, color, and respiration rate were done every 3 days. Chickpea seed and pod showed a good nutritional profile based on the protein, fiber, calcium, potassium, and iron content. Also, in both tissues pH = 6.0 was observed. The cell anatomy of the pod showed a well structured cuticle at day 0, which remained compacted through the storage; also, a change in cells from the parenchyma towards sclerenchyma was observed, indicating cell aging. The 1-MCP treatments significantly decreased weight loss and metabolic activity of chickpeas as compared to control samples; however, none of the treatments showed a significant effect on green color retention.

El objetivo de esta investigación fue caracterizar los componentes de calidad del fruto de garbanzo, describir la anatomía de la vaina y buscar tecnología poscosecha que permitan prolongar la vida del fruto. Se cosecharon garbanzos verdes cv. 'Blanco Sinaloa'; en la vaina y semilla se realizó el análisis proximal, minerales, pH, acidez y sólidos solubles totales. En la vaina se observó la histología del tejido a los 0, 6 y 12 días. Cuatro lotes de frutos fueron tratados con 1) 0.5 μl·L-1 y 2) 1.0 μl·L-1 de 1-metilciclopropeno (1-MCP, al 14 %), 3) asperjado con agua a 65 °C y 4) testigo (sin tratar). Los garbanzos se almacenaron por 12 días a 10 °C en envases de polietileno. Cada tres días se evaluaron la pérdida de peso, el color exterior y la respiración de los frutos. La semilla y la vaina de garbanzo tuvieron adecuada concentración de proteínas, fibra, calcio, potasio y hierro; y un pH = 6. La anatomía celular de la vaina tuvo una cutícula bien estructurada el día cero, la cual se compactó durante el almacenamiento; también, se observaron cambios de las células del parénquima a esclerénquima. Los frutos tratados con 1-MCP redujeron significativamente la pérdida de peso y la actividad metabólica en comparación con el testigo; sin embargo, ningún tratamiento mostró un efecto significativo sobre la retención del color verde de los frutos.

The effect of biocompatible products on the growth of cucumber powdery mildew (Sphaerotheca fuliginea) was evaluated. Plants were treated with dispersions or solutions of sunflower, olive and neem oils and potassium bicarbonate, potassium silicate and monopotassium phosphate, and compared with azoxystrobim. The most effective treatments for reducing the severity of powdery mildew damage in the cucumber foliage were those that contained the higher doses of potassium silicate, potassium bicarbonate, olive oil, monopotassium phosphate and neem oil showed a disease severity similar to azoxystrobin. Potassium bicarbonate, potassium silicate and oils were phytotoxic. Disease control was worse on climatic conditions with higher temperatures.

Se comparó el efecto de seis productos biocompatibles sobre el desarrollo de Sphaerotheca fuliginea en plantas de pepino cv. Borja en dos épocas de cultivo. Se trataron semanalmente las plantas con aspersiones o soluciones de aceites de girasol, oliva y neem, bicarbonato de potasio, silicato de potasio y fosfato monobásico de potasio, comparándose contra azoxystrobin. Los tratamientos más efectivos en reducir la severidad de daño de cenicilla en el follaje de pepino fueron los que contenían las dosis altas de silicato de potasio, bicarbonato de potasio, aceite de oliva, fosfato de potasio y aceite de neem, con un grado de control similar al azoxystrobin. El bicarbonato de potasio, silicato de potasio y los aceites vegetales presentaron fitotoxicidad. El grado de control de la cenicilla por productos fue menor en la etapa de cultivo donde se presentaron temperaturas más altas.

Because of the economic impact of mango (Mangifera indica L.) fruit cv. 'Ataulfo' in México, the effect of 1-MCP (1-methylcyclopropene) and of a chitosan-based edible coat (EC) on the quality parameters and shelf life of 'Ataulfo' mango, and the effect of 1-MCP on the hydrolytic activity of cell wall enzymes were studied in this work. Physiologically mature fruits were assigned into six treatments: 1) Control; 2) EC; 3) 1-MCP, 400 nL L-1; 4) 1-MCP, 800 nL L-1; 5) EC + 1-MCP, 400 nL L-1; and 6) EC + 1-MCP, 800 nL L-1. Mangos were first stored for 7 d at 12 °C and then transferred to 20 °C for 15 d. Weight loss, firmness, pH, titratable acidity, total soluble solids (TSS), respiration rate and the activities of polygalacturonase (PG), cellulase (Cx), α and β-galactosidase and p-glucosidase were evaluated. 1-MCP and EC did not reduce weight loss in mango, but fruits treated with 400 nL L-1 of 1-MCP maintained the highest values of firmness throughout storage, whereas the control and EC treated fruits had already lost more than 50 % of their initial firmness 3 d after treatment, and the commercial quality was lost by day 9. Fruits did not show any significant change in pH and TSS by the imposed treatments during 12 d at storage condition. Respiration decreased in all treated fruits as compared to controls; 1-MCP + EC treated fruits delayed their climacteric peaks by 3d. PG and Cx activities increased during fruit ripening, and PG activity was higher in control compared to fruits from other treatments. The highest activity of both glycosidases was observed on day 6. In fruits treated with 1-MCP, a reduction of PG and Cx activities was observed.

Por la importancia económica del mango (Mangifera indica L.) cv. 'Ataulfo' en México, en este trabajo se estudió el efecto de 1-MCP (1-metilciclopropeno) y de una película comestible (PC) a base de quitosano, sobre variables de calidad y de vida de anaquel del mango 'Ataulfo', así como el efecto del 1-MCP sobre la actividad de enzimas hidrolíticas de la pared celular. Los frutos en madurez fisiológica se dividieron en seis tratamientos: 1) Testigo; 2) PC; 3) 1-MCP, 400 nL L-1; 4) 1-MCP, 800 nL L-1; 5) PC + 1-MCP, 400 nL L-1; y 6) PC + 1-MCP, 800 nL L-1. Los frutos se almacenaron 7 d a 12 °C y se transfirieron a 20 °C por 15 d. Se evaluó pérdida de peso, firmeza, pH, acidez titulable y sólidos solubles totales (SST), respiración y actividad enzimática de poligalacturonasa (PG), celulasa (Cx), α- y β-galactosidasa y β-glucosidasa. Los tratamientos con 1-MCP y PC no redujeron la pérdida de peso de los frutos, pero los tratados con 400 nL L-1 de 1-MCP mantuvieron mayor firmeza. Luego de 3 d de almacenamiento los frutos testigo y PC perdieron más de 50 % de la firmeza, y a los 9 d perdieron su calidad comercial. No se observaron cambios en pH y SST por efecto de los tratamientos en los frutos almacenados por 12 d. La respiración disminuyó en todos los frutos tratados con relación al testigo; los frutos con 1-MCP+PC retrasaron en 3 d el máximo climatérico. La actividad de PG y Cx se incrementó durante la maduración y la primera fue mayor en frutos testigo que en los tratados, mientras que la máxima actividad de glicosidasas se observó en el día 6. En los frutos tratados con 1-MCP se notó una reducción en las actividades de PG y Cx.