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The large amount of olive cultivars conserved in germplasm banks can be used to overcome some of the challenges faced by the olive growing industry, including climate warming. One effect of climate warming in olive is the difficulty to fulfill the chilling requirements for flowering due to mild winter temperatures. In the present work, we evaluate seven olive cultivars for their adaptation to high winter temperatures by comparing their flowering phenology in the standard Mediterranean climate of Cordoba, Southern Iberian Peninsula, with the subtropical climate of Tenerife, Canary Islands. Flowering phenology in Tenerife was significantly earlier and longer than in Cordoba. However, genotype seems to have little influence on the effects of the lack of winter chilling temperatures, as in Tenerife. This was found even though the cultivars studied had a high genetic distance between them. In fact, all the cultivars tested in Tenerife flowered during the three-year study but showed asynchronous flowering bud burst. ‘Arbequina’ showed an earlier day of full flowering compared with the rest of the cultivars. The results observed here could be of interest to refine the phenological simulation models, including the length of the flowering period. More genetic variability should be evaluated in warm winter conditions to look for adaptation to climate warming.

In this note, we use an extension of the trial equation method (also called the direct integral method) for partial differential equations with non-constant coefficients to derive exact solutions in the form of nonlinear waves. The model considered generalizes other classical models from physics like the Klein–Gordon equation, the $$(1 + 1)$$ -dimensional $$\phi ^4$$ -theory, the Fisher–Kolmogorov equation from population dynamics, and the Hodgkin–Huxley model which describes the propagation of electrical signals through the nervous system. As a particular example, the cylindrically symmetric cubic nonlinear Klein–Gordon equation is considered herein.

In this work, we propose a discrete system to model the dynamics of individual opinions when the agents of a population have three equally likely choices. The social network consists of a finite number of agents with pairwise interactions at discrete times, and the opinion space is identified as a triangle in the plane. After a suitable homotopic transformation, one may convert the opinion space into the classical circle S 1 of the Cartesian plane. The opinion of each agent is updated following a general nonlinear law which considers individual parameters of the members. We establish conditions that guarantee the existence of attracting points (or strong consensus), and infer the existence of attracting intervals (identified here as weak consensus). Moreover, we notice that the conditions that lead to global consensuses are independent of the weight matrix and the number of agents in the network. The simulations obtained in this work confirm the validity of the analytical results.

Olive flowering phenology is highly affected by climatic conditions. Phenological models have been developed to forecast flowering date on olive mainly based on temperature. These models have used flowering datasets collected from trees growing under Mediterranean climatic conditions. In most of the cases, in those conditions, chilling requirements are rapidly fulfilled. In other cases, artificial modifications of the climatic conditions has been practiced by using growth chambers. In the present work, we compare the flowering phenology of ‘Picual’ and ‘Arbequina’ olive cultivars in Mediterranean conditions of Andalucia, Southern Spain, with those in Tenerife, Canary Islands with Sub-Tropical climate. The climatic conditions of Tenerife respect to Andalucia promoted an earlier flowering date but, more importantly, a much longer flowering period. This is mainly produced by an asynchronous flowering bud burst that will generate negative impacts on yield and quality. Quite likely, those differences on flowering phenology between Andalucia and Tenerife climatic conditions are mainly caused by the lack of winter chilling in Tenerife locations. Based on those results, we propose that future works studying the effect of lack of winter chilling on olive should include the length of the flowering period as a parameter to be modeled. Besides, studies on natural climatic conditions with warm winters, as the one here reported, are needed to really assess the effect of winter chilling on olive.

Se llevó a cabo un ensayo en el estado Trujillo, Venezuela, con el objetivo de evaluar el comportamiento morfoestructural de Albizia lebbeck, Leucaena leucocephala (ecotipo Trujillo) y Erythrina fusca en condiciones de vivero. Se utilizó un diseño completamente aleatorizado para mediciones repetidas en el tiempo y diez réplicas por especie. Las variables estudiadas fueron: altura de la planta; diámetro del tallo y de las ramas; número de hojas, ramas, raíces y nódulos totales; y longitud de la rama y de la raíz. Al final de la evaluación (18 semanas) no se observaron diferencias significativas entre L. leucocephala y E. fusca en la altura de la planta (45,2 y 51,0 cm), el diámetro del tallo (0,65 y 0,78 cm), el número de hojas (43 y 45) y de ramas (17 y 18) y la longitud de la raíz (32,1 y 36,5 cm). A. lebbeck sólo se destacó en el número de raíces (61) y de nódulos totales promedio (6). Los resultados permiten concluir que con la utilización de un sustrato alcalino en vivero, L. leucocephala y E. fusca exhibieron un comportamiento morfoestructural aéreo similar y superior que el de A. lebbeck; mientras que la albizia mostró mejores resultados en la morfoestructura radical.A trial was conducted in the Trujillo state, Venezuela, in order to evaluate the morphostructural performance of Albizia lebbeck, Leucaena leucocephala (Trujillo ecotype) and Erythrina fusca under nursery conditions. A completely randomized design was used for repeated measurements in time and ten replications per species. The studied variables were: plant height; stem and branch diameter; number of leaves, branches, roots and total nodules; and branch and root length. At the end of the evaluation (18 weeks) no significant differences were observed between L. leucocephala and E. fusca in plant height (45,2 and 51,0 cm), stem diameter (0,65 and 0,78 cm), number of leaves (43 and 45) and branches (17 and 18) and root length (32,1 and 36,5 cm). A. lebbeck only stood out for the number of roots (61) and average total nodules (6). The results allow concluding that with the utilization of an alkaline substratum in nursery, L. leucocephala and E. fusca showed a similar aerial morphostructural performance and higher than that of A. lebbeck; while albizia showed better results in root morphostructure.

In this work, we consider a system of coupled finite-difference equations which incorporates a variety of opinion formation models, and use it to describe the dynamics of opinions on controversial subjects. The social network consists of a finite number of agents with pairwise interactions at discrete times. Meanwhile, the opinion of each agent is updated following a general nonlinear law which considers parameters identified as the personal constants of each of the members. We establish conditions that guarantee the existence of global attracting points (strong consensus) and intervals (weak consensus). Moreover, we note that these conditions are independent of the weight matrix and the number of agents of the network. Two particular scenarios are investigated numerically in order to confirm the validity of the analytical results.

Mediante el análisis descriptivo, de componentes principales y de clasificación automática (ACA), se llevó a cabo un experimento para caracterizar la composición nutricional del follaje de 53 accesiones del género Leucaena (37 L. leucocephala, 7 L. macrophylla, 5 L. lanceolata, 2 L. diversifolia, 1 L. glauca y 1 L. esculenta) establecidas en Matanzas, Cuba. Se determinó la composición química, los niveles de metabolitos secundarios y la degradabilidad ruminal. En general, las accesiones presentaron excelente composición química para ser utilizadas como suplemento en la alimentación de rumiantes (PC: 25,71 ±3,94%; FDN: 46,91 ±2,09%; cenizas: 7,48 ±0,96%; DMS: 60,24 ±9,90%). Los indicadores que explicaron mejor las variaciones entre las accesiones fueron los componentes de la fracción fibrosa y la polifenólica, la concentración de mimosina y la degradabilidad ruminal. Sin embargo, la fracción proteica, los niveles de materia seca, de fitatos, minerales y las cenizas presentaron pocas fluctuaciones. Mediante el ACA se identificaron tres grupos con características nutricionales diferenciadas entre sí. Las accesiones de L. macrophylla, L. diversifolia y L. esculenta presentaron mayor concentración de metabolitos secundarios y menor degradabilidad ruminal que las pertenecientes a L. leucocephala, L. lanceolata y L. glauca, las cuales mostraron los mejores resultados. La degradación de la MS, PC y FDN se vio afectada por los contenidos de fibra, polifenoles totales, taninos precipitantes y taninos condensados.Through the descriptive analysis, main component analysis and automatic classification, a trial was conducted to characterize the nutritional composition of the foliage of 53 accessions from the Leucaena genus (37 L. leucocephala, 7 L. macrophylla, 5 L. lanceolata, 2 L. diversifolia, 1 L. glauca and 1 L. esculenta) established in Matanzas, Cuba. The chemical composition, levels of secondary metabolites and ruminal degradability were determined. In general, the accessions showed excellent chemical composition to be used as supplement in ruminant feeding (CP: 25,71 ±3,94%; NDF: 46,91±2,09; Ash: 7,48 ± 0,96%; DMD: 60,24 ± 9,90%). The indicators that better accounted for the variations between accessions were the components of the fibrous and polyphenolic fraction, mimosine concentration and ruminal degradability. However, protein fraction, dry matter and phytate rates, minerals and ash showed little fluctuation. By means of the ACA three groups were identified with differentiated nutritional characteristics among themselves. The accessions of L. macrophylla, L. diversifolia and L. esculenta showed higher concentration of secondary metabolites and lower ruminal degradability than the ones belonging to L. leucocephala, L. lanceolata and L. glauca, which showed the best results. DM, CP and NDF degradation was affected by fiber, total polyphenol, precipitable tannin and condensed tannin contents.