In this doctoral dissertation, we examined the metabolic and physiological responses of four different cultivars of blueberries (Vaccinium corymbosum L.) to modified microclimatic conditions in various types of protected environments. We monitored the content of primary and secondary metabolites in fruit grown in a high tunnel and under a hail net on plants cultivated in pots and ridges. The microclimate in the high tunnel enhanced fruit ripening compared to the hail net, while plants under the hail net exhibited more intense growth, higher yields, and a greater content of phenolic compounds in the fruit. The pots had a higher substrate temperature than the reef, which increased the temperature fluctuations, meaning that the size of the pots did not have a negative effect on the measured parameters. In the high tunnels, plants responded to higher air temperatures at the physiological level (net photosynthesis, chlorophyll fluorescence) and in the biochemical profile of the leaves (chloroplast pigments, phenolic compounds). A similar effect was observed in plants growing under photoselective nets. The latter influenced the biochemical profile of the fruit at harvest and their performance during storage, affecting sugar, organic acid, phenolic, and volatile compound content among treatments. For the cultivar 'Aurora,' we concluded that the non-destructive measurement of chlorophyll absorbance is an effective method for assessing the optimal ripeness of the fruit directly on the plant.
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