Studio dei principali fattori che influenzano l’insorgenza dell’atrofia del capolino in carciofo Spinoso Sardo

Head atrophy often observed on globe artichoke cv Spinoso sardo can be mainly related to GA3 application or to air temperature over 26°C during the apical bud differentiation. The relationships between air temperature and plant water status during bud differentiation, as well as air temperature and GA3 application, are not yet studied. The topics of the thesis are relevant in plant physiology and for their applicability in globe artichoke open field growing.In chapter 1 we validated and implemented a simplified degree days prevision model, suitable to predict the globe artichoke “Spinoso sardo” phenological stages and apical bud differentiation. Our data suggest the effectiveness of the degree days model and its suitability for decision support.In chapter 2 we studied the relationships between air temperature and stomatal conductance, transpiration and net photosynthesis by the application of sprinkler irrigation on open field. Our data suggest that sprinkler irrigation is able to reduce canopy temperature and increase instant transpiration at noon. Globe artichoke “Spinoso sardo” grown under sprinkler irrigation showed a reduced incidence of head atrophy.In chapter 3 we studied the relationships between GA3 application and air temperature observed in contrasting environments. Globe artichoke plants under a combined effect of GA3 application under high temperature showed 100% of atrophic heads or were not able to produce commercial heads.