Efecto de la alternativa productiva en la fenología y algunas variables productivas en olivo (Olea europaea L.) "Frantoio" en la Región Metropolitana

Tesis presentada como parte de los requisitos para optar al Título Profesional de Ingeniero Agrónomo y al Grado de Magíster en Ciencias Agropecuarias, Mención Producción FrutícolaEl objetivo de la investigación fue estudiar la influencia de la carga frutal en el grado de alternancia productiva de olivos ‘Frantoio’, y sus efectos en el comportamiento fenológico, variables vegetativas, productivas y de rendimiento de aceite, con el fin de permitir al olivicultor generar estrategias de manejo conducentes a disminuir la vecería mediante una mejor integración de las prácticas agronómicas. Para ello, durante las temporadas 2011-2012 y 2012-2013, de baja y alta carga frutal, respectivamente, se realizó un seguimiento quincenal de variables fenológicas; crecimiento vegetativo: brotes y raíces; y reproductivo: tipo de flor, cuaje, crecimiento de fruto y acumulación de aceite. Además, se midió la producción por árbol, y se estimó la carga frutal y el rendimiento de aceite a cosecha. Los principales resultados muestran una fuerte influencia de la carga frutal en las variables evaluadas. La distribución e intensidad del crecimiento vegetativo, radical y aéreo, fue más acotado y de menor intensidad en la temporada de alta fructificación, produciéndose, gran parte del crecimiento vegetativo, previo a la floración. Respecto a las variables reproductivas, se observó, en la temporada de baja floración, un mayor porcentaje de flores perfectas y cuaje respecto a la de alta carga. Estos resultados sugieren un mecanismo parcial de compensación en condiciones de baja floración; sin embargo, este mecanismo no alcanza a compensar la menor producción de la temporada. En relación a la producción y rendimiento de aceite, se observó que la producción promedio de un árbol, en dos temporadas consecutivas, de baja y alta carga frutal, es constante, independiente del nivel de producción de los árboles, sugiriendo un potencial óptimo de producción en el cual no se presenta alternancia productiva. Éste, a su vez, parece estar relacionado con la tasa de ganancia máxima de rendimiento de aceite por kg de fruta producido. De esta manera, al sobrepasar el óptimo de producción, en un año de alta carga frutal, esta tasa disminuye. Sin embargo, aún se requieren más estudios que profundicen estos resultados, en otras condiciones y variedades.The aim of this research was to study the influence of crop load on the degree of alternate bearing of ‘Frantoio’ olive trees and its effects on phenology, vegetative growth, yield level and oil yield variables. This would allow an olive grower to generate management strategies leading to decrease the biennial bearing through better integration of agronomic practices. Accordingly, during the 2011-2012 and 2012-2013 seasons, a bi-weekly monitoring of phenological variables was performed; vegetative growth: shoots and roots; and reproductive: type of flowers, fruit set, fruit growth and oil accumulation. Moreover, the production per tree was measured and crop load and oil yield at harvest was estimated. The main results show a strong influence of crop load on the variables evaluated. The radical and shoot growth distribution and intensity was more limited and less intense in high-fruiting season (On-year), producing much of vegetative growth before flowering. Regarding reproductive variables it was observed a higher percentage of perfect flowers and fruit set relative to the high crop load in the low flowering season (Off-year). These results suggest a partial compensation mechanism when low levels of flowering occurs; however, this mechanism, can not compensate the lower yield of that season. Regarding total and oil yield, it was found that the average yield of a tree in two consecutive seasons, with low and high crop load, is constant, independent of tree yield level, suggesting an optimal yield where alternate bearing is not present. This, in turn, appears to be related to the maximum gain rate of oil yield per kg of fruit produced. Thus, the optimal yield exceeds in a year of high crop load, this rate decreases. However, further studies to explore these results in other conditions and varieties are required

Olive inflorescence and flower development as affected by irradiance received in different positions of an east-west hedgerow

Olive lree productivity is highly respons1ve to radiation condit10ns, so understanding the responses of the developmental processes that determine yield, among these inflorescence and flower differentiation, is essenllal for orchard design and management This is particularly true in the new intensive hedgerow orchards, where radiation reception highly depends on canopy height and row onentation and spacing. In an E-W (East- West) oriented hedgerow (cv. Arbequina) located in Toledo (Spain), inflorescences were sampled from both sides (South (S) and North (N)) of the hedgerow canopy, at heights 0-0.4, 0.8- 1.2, and 1.6-2.0 m above the so1l. Floral quality was determined at diffe rent levcls of morphogenetic organization: inflorescence, flower, and ovary. Daily irradiance intercepted during flower development by each canopy posit10n was estimated using a model. The more highly illuminated S side received 28% overall more irradiance than the N side. Upper layer irradiance was greater than bottom )ayer, 4.1 and 1.8 times for N and S sides, respectively. lnflorescence structure, flower number and perfect flower proportion were similar at different heights on the S side. In contrast, N side upper !ayer inflorescences were longer and had more nodes, total flowers and perfect flowers than at lower hedgcrow heights. At cach height perfcct flower proportion was higher on the S than N side, whilc thc remaining lraits were similar belween sides. Ovary tissue sizes, observed in histological preparat10ns, did not vary among heights on each side, but was higher on the S than N side due to endocarp size. Simulated irradiance at flowering explained 88% of the observed variat1on of perfect flower number per inflorescence. Overall, the results emphasize the importance of irradiance at different hedgerow sides and heights on olive inflorescence and floral slructures

Olive floral development in different hedgerow positions and orientations as affected by irradiance

Irradiance received within the olive hedgerow canopy varies with respect to row orientation, spacing and hedge dimensions. These orchard management criteria offer the opportunity for improving productivity based on understanding the responses of yield-determining processes to irradiance. How irradiance influences inflorescence and flower development, the initial steps in fruit formation, are fundamental components of these processes. In this study we evaluated flowering and fruiting parameters in 5 hedgerow positions (defined by hedgerow side and vertical layer above soil) for N S (North-South) and E W (East West) olive hedgerows (cv. Arbequina). The canopy layers and orientations provided a wide gradient of irradiance received and the relationship of estimated mean daily irradiance for annual and for short periods during floral development and initial fruit set was explored. The numbers of inflorescences and fruits per layer increased from the less illuminated base to more illuminated upper canopy layers. Axillary bud number per shoot also increased toward more illuminated positions, while the proportion of floral buds was unresponsive to the irradiance micro environment at different positions within the hedgerows. Inflorescence length, node and flower number per inflorescence, and perfect flower percentage increased with position illumination. Ovary quality, indicated by ovule differentiation, was consistently high, independent of position, but ovary size showed some slight significant increases with illumination, mainly in the endocarp. Flowers/inflorescence, fruits/fruiting inflorescence and inflorescence and fruit number per position correlated positively and significantly with estimated irradiance similarly for annual and short periods (r range from 0.49 to 036). Despite improved flowering parameters with greater irradiance, no consistent differences among positions were found for percentage of inflorescences bearing fruit and fruit number per inflorescence. Instead, our results indicated that different fruit numbers among canopy positions were primarily due to an irradiance effect on vegetative growth, causing more and longer fruiting shoots and therefore more total flowering sites (nodes) per layer, with only a small contribution by inflorescence structure and flower quality.Spanish Junta de Andalucia-European Regional Development Fund (ERDF) P11-AGR-7835 ERASMUS-Mundu