Eleven organically grown apple cultivars and 11 apple cultivars of integrated production from Austria and Slovenia were analyzed by HPLC for the content of phenolic compounds in peel and pulp. We identified chlorogenic acid, p-coumaric acid, procyanidin B3, protocatechuic acid, (−)-epicatechin, phloridzin, rutin and quercetin-3-rhamnoside in apple peel. In apple pulp, (+)-catechin was also identified in all the cultivars. Some other phenols (procyanidin B3, rutin and quercetin-3-rhamnoside) could not be identified or were not properly separated. With regard to the phenolic content in the apple peel, there were no differences between organically grown apple cultivars and apple cultivars of integrated production. Organically grown apples, however, exhibited a higher content of phenolic substances in the apple pulp compared with the apple cultivars of integrated production. This may be due either to the different genotype source or to the growing technology. Higher concentrations of phenolic compounds in organically grown cultivars could be a result of plant response to stress. The apple peel contained higher concentrations of identified phenols than the pulp. The apple peel represents up to 10% of the whole fruit; therefore the phenolsic compounds in the pulp are of greater importance to the consumer than the phenolic compounds in the peel.

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Objective: This study was carried out to obtain data about the sugar-, acid-and phenol content of apple cultivars from organic and integrated fruit cultivation, with reference to their role in human health and especially for diet recommendations. Setting: Styria (Austria) and Slovenia. Interventions: HPLC, Spectral Photometry, organoleptic and olfactory tests. Results:The total sugar content of most cultivars from integrated cultivation ranged between 115 and 160 g/kg. Some cultivars from organic growing reached higher values. The acid content of both cultivar types was similar. The phenol content in organically grown cultivars was much higher than that of the ones from integrated cultivation. Conclusion: Knowledge of the sugar content is very important for diabetic patients, owing to the assumption of general diet recommendations that 100 g fruit contain 12 g carbohydrates. This applies to most well-known cultivars like Golden Delicious or Gala, but not to most of the regional cultivars. For diabetics, it is necessary to know the carbohydrate content of food precisely, in order to adapt the amount of insulin to the ingestion. So, it is helpful to know the sugar content of each regional cultivar. Moreover, very high levels of phenolic compound in organically grown cultivars, and with it its importance for human health leads to the recommendation to eat regional fruits from organic fruit growing instead of those grown under integrated cultivation.

The extraordinary drought during the summer of 2003 in Central Europe allowed to examine responses of adult beech trees (Fagus sylvatica) to co-occurring stress by soil moisture deficit and elevated O 3 levels under forest conditions in southern Germany. The study comprised tree exposure to the ambient O 3 regime at the site and to a twice-ambient O 3 regime as released into the canopy through a free-air O 3 fumigation system. Annual courses of photosynthesis (A max ), stomatal conductance (g s ), electron transport rate (ETR) and chlorophyll levels were compared between 2003 and 2004, the latter year representing the humid long-term climate at the site. ETR, A max and g s were Communicated by H. Jones lowered during 2003 by drought rather than ozone, whereas chlorophyll levels did not differ between the years. Radial stem increment was reduced in 2003 by drought but fully recovered during the subsequent, humid year. Comparison of AOT40, an O 3 exposure-based risk index of O 3 stress, and cumulative ozone uptake (COU) yielded a linear relationship throughout humid growth conditions, but a changing slope during 2003. Our findings support the hypothesis that drought protects plants from O 3 injury by stomatal closure, which restricts O 3 influx into leaves and decouples COU from high external ozone levels. High AOT40 erroneously suggested high O 3 risk under drought. Enhanced ozone levels did not aggravate drought effects in leaves and stem.

Ground-level ozone (O(3)) has gained awareness as an agent of climate change. In this respect, key results are comprehended from a unique 8-year free-air O(3)-fumigation experiment, conducted on adult beech (Fagus sylvatica) at Kranzberg Forest (Germany). A novel canopy O(3) exposure methodology was employed that allowed whole-tree assessment in situ under twice-ambient O(3) levels. Elevated O(3) significantly weakened the C sink strength of the tree-soil system as evidenced by lowered photosynthesis and 44% reduction in whole-stem growth, but increased soil respiration. Associated effects in leaves and roots at the gene, cell and organ level varied from year to year, with drought being a crucial determinant of O(3) responsiveness. Regarding adult individuals of a late-successional tree species, empirical proof is provided first time in relation to recent modelling predictions that enhanced ground-level O(3) can substantially mitigate the C sequestration of forests in view of climate change.