Thinning of Organic Apple Production with Potassic Soap and Calcium Polysulfide at the North of Spain.

Asturias, in the North West coast of Spain, is a region with old tradition at cultivation of apple and its transformation to cider. The production of apple is mainly done under traditional uses and semi-extensive or semi-intensive system and with local cultivars. Thinning strategy is little practiced and the biennial bearing cycle is one of the main problems for the farmers. The production of apple under organic techniques in Asturias is still limited but increasing. Since 2005, experiments have been conducted on several cultivars (‘Raxao’, ‘Xuanina’ and ‘Gold-Rush’) to evaluate the effects of Potassic Soap (with or without olive oil) and Calcium Polysulfide as thinning products. We present here the first promising results of these experiments. With different concentrations of both products we have increased the apple production of two cultivars for the period 2006- 2007. There were positive effects on the vegetative growth of the trees and on the quality of apples. In the spring 2007 we initiated new experiments with other cultivars (‘Durona de Tresali’, ‘Solarina’, ‘Raxao’, ‘Regona’) in order to confirm our results. The new experiments also include the comparison of their effects with those of commonly used chemical products and with those of manual thinning techniques

Molecular and morphological characterization of local apple cultivars in Southern Spain

The number of local and traditional fruit cultivars in Andalusia (Southern Spain) has decreased dramatically since the 1970s when new commercial cultivars from breeding programs were introduced, replacing old varieties, and thus decreasing genetic diversity. The present study was included in a genetic resources project with the objective of identifying and preserving traditional fruit tree cultivars in Southern Spain. The goal of this study was to begin the characterization of 29 apple accessions (Malus x domestica Borkh) belonging to 13 traditional cultivar denominations. For molecular characterization studies, 12 simple sequence repeat markers previously developed for apple species were used. Morphological characterization was performed using 33 fruit traits. A total of 115 alleles were amplified for the 12 loci, ranging from 7 (CH01h01, CH01h10, and GD 12) to 13 alleles per locus (CH02c11). Forty-one alleles were unique to specific genotypes. The locus with the highest number of detected unique alleles was CH01f03b with 6 alleles. Expected heterozygosity ranged from 0.74 for CH01h10 to 0.88 for CH02c11, with an average of 0.82. Observed heterozygosity varied from 0.45 for CH01h01 to 1.0 for CH02d08, with an average of 0.86. Three homonyms were found for accessions belonging to varieties 'Maguillo', 'Pero Minguela', and 'Castellana'. The most discriminant morphological characters studied revealed no homonyms or synonyms among cultivar denominations, although they are useful for describing varietal characteristics that have not been previously definedFEDER RF-2007-00027-C06-0

A novel method for the determination of total 1,3-octanediols in apple juice via 1,3-dioxanes by solid-phase microextraction and high-speed gas chromatography

In this work, a novel, simple and fast method based on solid-phase microextraction (SPME) followed by high-speed gas chromatography (HSGC) was developed for the analysis of total 1,3-octanediols in apple juices by means of derivatization reaction to volatile 1,3-dioxanes. The derivatization reaction, SPME conditions, glycosidically bound fraction and 1,3-nonanediol as a surrogate standard were studied. The formation of 1,3-dioxanes from 1,3-diols was confirmed by GC–MS. The method was validated obtaining a regression coefficient (r2) of 0.9996, precisions between 0.3 and 9.8%, extraction recoveries in the range 94.7–112.2% and LOD of 2.9 g l−1. Experimental design has been employed in the optimization of extraction factors and robustness assessment. The method was applied to the analysis of 21 Asturian apple varieties finding a double reciprocal relationship between the concentrations of saturated and unsaturated 1,3-octanediol

Parasitoides de carpocapsa Cydia pomonella en plantaciones de manzano de Asturias

Se ha realizado un estudio de los parasitoides que emergen de larvas de carpocapsa recolectadas mediante bandas de cartón en plantaciones de manzano de Asturias. Emergieron 257 parasitoides pertenecientes a 4 especies: Ascogaster quadridentata Wesmael (51,4 % del total de parasitoides), Pristomerus vulnerator Panzer (35,0 %), Liotryphon caudatus Ratzeburg (9,7 %) y Trichomma enecator Rossius (3,9 %). La tasa media de parasitismo fue del 15,1 %, aunque se registraron diferencias entre años (28,7 y 9,0 %) y entre plantaciones (3,2 - 38,5 %). También hubo variaciones en la tasa de parasitismo específica tanto entre años como entre plantaciones. Liotryphon caudatus, T. enecator y P. vulnerator emergieron antes que los adultos de carpocapsa y A. quadridentata ligeramente después. Además, los machos de L. caudatus emergieron antes que las hembras. La sex-ratio de P. vulnerator y T. enecator no difirió de 1:1, mientras que para L. caudatus fue significativamente mayor el número de hembras. Ascogaster quadridentata y P. vulnerator provocaron la castración de las larvas parasitadas así como una reducción en el tamaño de las mismas. Ascogaster quadridentata, P. vulnerator y T. enecator presentaron dos generaciones anuales, mientras que los datos sugieren que L. caudatus podría desarrollar al menos tres. La estrecha sincronización con la fenología de la carpocapsa sugiere que este lepidóptero podría ser el principal hospedador de estos cuatro parasitoides