The influences of several management practices, as pruning, girdling, chemical and manual thinning on apple fruit size and yield efficiency, are known. Basically, yield improvement is achieved by a successful management of source-sink relationships. However, scarce information is available today about the behavior of environmental factors. A research work was conducted on Gala apples at different locations in central Chile (between 34 and 38°S) among the years 20122016, with the objective to associate the differences detected on yield performance with the growing conditions expressed as the temperature regime during the time elapsed between autumn and flowering. For that, the mean, maximum, and minimum temperatures were used to describe weather during the autumns, winters, and early springs, for to be related with yield performance.
Crop load-adjusted yield efficiency ranged between 10.1 and 6.8 kg m-2 PARi, and fruit weight was found to be 134.4 g and 189.5 g among zones. The results showed that the crop load-adjusted yield and fruit size depended primarily on the maximum temperature during winter, and secondly, on season length (from bloom to harvest), with colder areas yielding better performance.
Annual accumulation of starch is affected by carbon reserves stored in the organs during the growing season and is controlled mainly by sink strength gradients within the tree. However, unfavorable environmental conditions (e.g., hail events) or application of management practices (e.g., defoliation to enhance overcolor in bicolor apple) could influence the allocation of storage carbohydrates. This preliminary research was conducted to determine the effects of early defoliation on the dry matter, starch, and soluble carbohydrate dynamics in woody organs, roots, and mixed buds classified by age and two levels of crop-load for one growing season in Abbé Fétel pear trees (Oct. 2012 to mid-Jan. 2013 in the northern hemisphere). Regardless of the organs evaluated (woody organs, roots, and mixed buds), an increase of soluble carbohydrate concentration was observed in these organs in the period between after harvest (October) and January (dormancy period). Among all organs, woody short-old spurs showed the highest increase (+93.5%) in soluble sugars. With respect to starch, woody organs showed a clear trend of decreasing in concentration between October and January. In this case, short-old spurs showed the smallest decline in starch concentrations, only 6.5%, whereas in other tree organs starch decreased by 34.5%. After harvest (October), leaves showed substantially higher starch and soluble sugar concentrations in trees with lower crop-loads. These results confirm that in the period between October and January, dynamic interconversions between starch and soluble carbohydrates occur at varying magnitudes among organs in pear trees.
Comprende la contratación de un Estudio de validación productiva, vinculada al establecimiento de nuevos huertos y cultivos, manejos agronómicos y creación de fichas técnicas por cada rubro con potencial identificado.
To determine the changes on the root-to-canopy system temperatura gradient and their effect of NSC concentration and allocations on different European plum tree organs and tissue, and to establish their relationship with phenology stages undes a scenario the climate change
la presente propuesta tiene como objetivo crear una red internacional
entre la Universidad de OHiggins, la Universidad de Chile y la Universidad de Maryland, con
un enfoque interdisciplinar, es decir integrando las disciplinas de las ciencias agronómicas,
ciencias naturales y las ciencias sociales para abordar desafíos relacionados con la
adaptación de los sistemas agrícolas costeros y servicios ecosistémicos de suelos a los
efectos de la intrusión marina. La red de colaboración, a desplegar en Pichilemu y Maullín,
permitirá robustecer y abordar esta temática en Chile, y así contribuir al desarrollo de
soluciones en la materia con alcances a nivel nacional.