Marlene Ayala

Evolución del daño por insolación de manzanas 'Granny Smith' durante el almacenaje refrigerado

)to reduce scald (the physiological disorder), and an equal number of non-treated apples were used as controls. The concentration of conjugated trienes (CTs) was determined and compared between the apparently healthy and damaged side of the same fruits. Sunscald, characterized by brown skin tissue, developed on the sunburnt side of the fruit, and superfi cial and senescent scald symptoms developed on the healthy side of the apple. A signifi cant and negative relationship between sunscald and scald were obtained in fruit treated with DPA. A low concentration of CT 281 was found on the sunburnt side of apples treated with DPA and 1-MCP. Application of 1-MCP and DPA controlled scald but not sunscald. DPA treatment resulted in better control of scald after 6 months of storage on fruit with moderate sunburn damage at the time of harvest.

13C Photoassimilate partitioning in sweet cherry (Prunus avium) during early spring

Stored reserves are critical for the early spring growth of reproductive and vegetative sinks in sweet cherry ( Prunus avium L.). To study the distribution of carbon storage reserves on new, highly productive hybrid rootstocks in sweet cherry, an experiment was established using 5-yr-old cv. ‘Regina’ on the semi-vigorous rootstock ‘Gisela®6’ (‘GI®6’). Using whole-canopy enclosure chambers, five trees were pulse-labeled three times with high levels of 13 CO 2 during the fall. At leaf drop, leaves, buds, wood, bark and roots were sampled for gas chromatography-mass spectrometry (GC-MS) analysis. The storage organs with the highest percentages of excess 13 C atoms were the roots and the older wood in the trunks, branches and buds. During the spring, newly developing organs (flowers, immature fruits and leaves) were sampled weekly from bloom to stage III of fruit development for additional GC-MS analysis. 13 C-reserves were remobilized and partitioned to flowers, fruits and young leaves from before budbreak (side green stage) until 14 days after full bloom (DAFB). The isotopic composition differed significantly between phenological stages, and the highest 13 C levels in the growing sinks were detected between bloom and fruit set. The reproductive organs had the strongest sink activity until 14 DAFB, and competition with spur leaf sink activity was apparent. It is proposed that reserve source limitation may impact fruit set and spur leaf development, which may ultimately impact the availability of photoassimilate during the later stages of fruit growth. En cerezo dulce ( Prunus avium L.), las reservas de almacenaje son importantes para el crecimiento de sumideros reproductivos y vegetativos en temprano en primavera. Para estudiar la distribucion de reservas de almacenaje carbonadas en portainjertos hibridos altamente productivos, se realizo un experimento utilizando arboles del cv ‘Regina’ injertados en el portainjerto semivigoroso ‘Gisela®6’ (‘GI®6’). La copa completa de cinco arboles fue encerrada con camaras transparentes de Mylar® para luego ser enriquecidos con altos niveles de 13 CO 2 en tres ocasiones durante el otono. Al estado fenologico de caida de follaje, yemas, hojas, madera, corteza y raices fueron muestreadas para ser analizadas mediante cromatografia de gases y espectrometria de masa. Los organos de almacenaje con los mayores niveles del parametro Exceso Atom 13 C (%) fueron raices, madera mas vieja del tronco y ramas y yemas. Durante primavera organos en desarrollo (flores, frutos inmaduros y hojas) fueron muestreados semanalmente desde floracion hasta Fase III de desarrollo de fruto para un analisis usando cromatografia de gases y espectrometria de masa. La composicion isotopica fue significativamente diferente entre organos y estados fenologicos. Los mayores niveles de 13 C en sumideros en desarrollo fueron detectados entre floracion y cuaja frutal. Los organos reproductivos tuvieron las mayor actividad sumidero hasta 14 (dias despues de plena flor, DDPF) compitiendo con las hojas de dardos. Segun lo observado, se propone que una limitacion en las reservas de almacenaje impactaria la cuaja de fruta y el desarrollo de area foliar, lo cual en definittiva afectaria la disponibilidad de fotoasimilados durante estados fenologicos mas tardios en el periodo de desarrollo de frutos en cerezo dulce.

Pruning effects on vegetative growth and fruit quality of 'Bing'/'Gisela®5' and 'Bing'/'Gisela®6' sweet cherry trees (Prunus avium)

Abstract M. Villasante, S. Godoy, J.P. Zoffoli, and M. Ayala. 2012. Pruning effects on growth and fruit quality of ‘Bing’/‘Gisela®5’ and ‘Bing’/‘Gisela®6’ sweet cherry trees ( Prunus avium ). Cien. Inv. Agr. 39(1): 117-126. Annual pruning is one of the most efficient ways to regulate crop load and renew fruiting wood in highly productive sweet cherry ( Prunus avium L.) combinations. Although Chilean growers did not previously prune cherry trees of more vigorous combinations, in recent years, the adoption of more dwarfing rootstocks and self-fertile cultivars has led to the inclusion of annual pruning as a practice in modern orchards. At first, this alteration in orchard management practices was not considered by growers, and thus, many of the initially established cherry orchards were not pruned as intensively as they should have been. As a consequence, many trees showed a reduction in fruit quality after 4 or 5 years of being planted, as they became overcropped and, consequently, registered reductions in their vegetative growth. There are only a few studies related to the effect of corrective pruning on dwarfing combinations that display an imbalance between reproductive and vegetative growth due to a reduction in the leaf area to fruit ratio of the tree. For this reason, the objective of this research was to study the effect of pruning in an orchard consisting of the dwarfing combinations ‘Bing’/‘Gisela®5’ (‘Bing’/‘GI®5’) and ‘Bing’/‘Gisela®6’ (‘Bing’/‘GI®6’), which shown a reduction in vigor, fruit quality and yield. Trees of both combinations were treated with a medium intensity pruning in late winter (early September). Several vegetative (shoot length, leaf area of spurs and shoots, trunk cross sectional area) and reproductive (total yield per tree, fruit growth and quality) parameters were evaluated after pruning. One of the most important effects of pruning for both combinations was an increase in the total current season shoot (CSS) growth, which was 112.5 and 125.6% for ‘Bing’/‘GI®5’ and ‘Bing’/‘GI®6’, respectively. Additionally, the average shoot length increased by 820.0 and 325.4% for ‘Bing’/‘GI®5’ and ‘Bing’/‘GI®6’, respectively. Furthermore, CSSs developed a higher leaf number in the pruned trees. There was no change in leaf number for reproductive spurs, but these had bigger leaves in the pruned trees, demonstrating increased total leaf area per spur. Additionally, pruning allowed crop load regulation and increased fruit size by 8.5 and 6.1% for ‘Bing’/‘GI®5’ and ‘Bing’/‘GI®6’, respectively. However, fruits from pruned trees showed a higher susceptibility to mechanical damage compared with unpruned trees of both combinations.

Effects of fruiting spur thinning on fruit quality and vegetative growth of sweet cherry (Prunus avium)

High density sweet cherry (Prunus avium) orchards using highly productive cultivars and dwarfi ng rootstocks usually require crop load regulation to achieve high quality fruit. Among the strategies used to reduce crop load in highly productive combinations, fruiting spur thinning (FST, spur extinction) before budbreak has been suggested to be an effective way to improve fruit size. Currently, there is little information about the effect of spur thinning on sweet cherry orchards using self-fertile cultivars grafted on vigorous rootstocks. For this reason, the objective of the present study was to evaluate the effects of manual FST on fruit quality and vegetative growth of the cultivar ´Lapins` grafted on the rootstock ´Mazzard F-12/1` with 0, 50 and 75% spur removal. Spur removal was carried out 28 days before full bloom (August 23). FST had no benefi cial effects on fruit size, total soluble solids or fruit weight. However, there were signifi cant differences in the foliar development of current season growth and fruiting and nonfruiting spurs. Although the leaf area to fruit ratio was high in all treatments, this parameter increased with the removal of 50 and 75% of fruiting spurs. Fruit quality did not increase, suggesting a possible sink limitation of Lapins` grafted on ´Mazzard F-12/1` or the presence of an alternative vegetative sink that is stronger than the fruit. However, further research is needed to clarify this point. Huertos modernos de cerezo (Prunus avium) con variedades productivas y portainjertos desvigorizantes requieren, generalmente, regulacion de carga frutal para obtener fruta de calidad exportable. El raleo de dardos frutales (RDF) (“extincion”) se ha sugerido como una practica de manejo para mejorar el balance entre crecimiento vegetativo y reproductivo. En Chile existe escasa informacion acerca del control de carga con RDF, por lo tanto, el objetivo de este ensayo fue evaluar el efecto del raleo manual de dardos en ramas de tres anos de arboles de la combinacion cultivar/portainjerto ´Lapins`/´Mazzard F-12/1`. El estudio evaluo el efecto del RDF en la calidad de la fruta y el crecimiento vegetativo de la temporada en tres niveles: 0, 50 y 75% de remocion de dardos por rama. La extincion de dardos se realizo 28 dias antes de plena fl or (23 de Agosto, 2006). El RDF no produjo efectos signifi cativos en el tamano, solidos solubles totales ni peso fresco de frutos. No obstante, hubo diferencias signifi cativas en el desarrollo foliar del brote apical, los dardos no frutales y los dardos frutales. Se observo una alta relacion hoja/fruto en todos los tratamientos, en efecto, este parametro aumento con un 50 y 75% de RDF. El ensayo no aumento la calidad de la fruta durante la temporada en estudio, posiblemente por una limitacion sumidero en la combinacion cultivar/portainjerto evaluada, o bien, la presencia de sumideros vegetativos alternativos mas fuertes que la fruta. Estudios posteriores se hacen necesarios para clarifi car estos puntos.

Distribution and recycling of canopy nitrogen storage reserves in sweet cherry (Prunus avium) fruiting branches following 15N-urea foliar applications after harvest

In sweet cherries, accumulated nitrogen (N) stores from the previous fall support early spring growth. To complement the N supply in the soil, Chilean growers use foliar urea applications after harvest. Information on the effectiveness of foliar N applications in sweet cherry is lacking. To study the canopy distribution of N applied as urea foliar sprays, an experiment involving a “Bing”/“Gisela ® 6” (“GI®6”) sweet cherry orchard was carried out in 2009/2010 in Chile (35o 09’ 53’’ S, 71o 20’ 43’’ W). The objective was to investigate N distribution and recycling in 3-year-old fruiting branches. A total of 120 branches (one per tree) were labeled using 15 N-urea. 15 N-urea was applied to the whole branch on four separate dates or treatments (TR) after fruit harvest: TR 1 =Jan, TR 2 =Feb, TR 3 =Mar and TR 4 =Apr. For each TR, a group of 15 N-labeled branches (10 replications) was destructively harvested at 3 times/stages: 15 days after the urea foliar application (DAA), dormancy and stage I of fruit development. Branches were divided into the various organs, dried (70 °C), ground and processed for GC-MS analysis. In all TR, labeled urea was taken up by the leaves and translocated to various organs. The highest N levels were observed in the fruiting section. TR 1 exhibited the highest N use efficiency (NUE%). Buds and bark showed the highest N derived from fertilizer (NDDF%) values. In all TR, stored N was recovered in the flowers, immature fruits and young leaves during the following spring. According to the results, urea sprays after fruit harvest constitute an alternative to complementing the N supply in the soil in sweet cherry trees using “GI®6”. En cerezo dulce, el nitrogeno (N) de almacenaje es acumulado en otono previo a la cosecha. Productores chilenos usan urea foliar despues de cosecha, pero la informacion disponible sobre de la efectividad de estas aplicaciones, en combinaciones enanizantes de cerezo dulce, es escasa. Por esta razon, en la temporada 2009/2010 se realizo un experimento para estudiar la distribucion de N aplicado como urea foliar, utilizando la combinacion “Bing”/“Gisela®6” (“GI ® 6”). Un total de 120 ramas fueron enriquecidas con 15 N-urea, la cual fue aplicada en 4 fechas distintas (Tratamientos; TR) despues de la cosecha: TR 1 =Ene, TR 2 =Feb, TR 3 =Mar and TR 4 =Abr. En cada TR, 10 ramas enriquecidas con 15 N- fue removida destructivamente en tres estados fenologicos: 15 dias despues de la aplicacion (15 DDA), Dormancia y fase I de desarrollo del fruto. Ramas individuales fueron divididas en diferentes organos/tejidos, y procesadas para analisis usando GC-MS. 15 N-urea fue absorbida por las hojas y translocada a los distintos organos. El contenido mas alto de N se registro en la seccion frutal. TR 1 registro la mayor eficiencia de uso del fertilizante. Yemas y corteza obtuvieron los mayores valores de nitrogeno derivado del fertilizante. En todos los tratamientos, el N almacenado fue remobilizado hacia flores, frutos inmaduros y hojas jovenes. Los resultados indican que aplicaciones foliares de urea pueden complementar aplicaciones de N al suelo en la combinacion “Bing”/“GI ® 6”.