CROCUS SATIVUS: FROM LIGHT TO SHADE: EFFECTS ON PHOTOSYNTHESIS AND PHOTOSYNTHETIC APPARATUS
Saffron is a plant with great economic and medicinal interests, and it requires optimal conditions for the success of its cultivation. Usually, it grows in full sun. However, no sources are documenting the degree of shade tolerance of this species. As a result, an experiment was carried out in 2016 and 2017, in the Experimental station of the Faculty of Sciences of Oujda in eastern Morocco, to study the effect of different levels of shading on chlorophyll pigments and the photosynthetic capacity of saffron (Crocus sativus). Saffron was grown for 24 months under different types of shading: 0% (control), 30%, 50%, and 70%. The results obtained from the study showed that shade significantly affected the response of the saffron plant. Plants grown under 30%, 50%, and 70% shade indicated that length, leaf area, leaf area ratio (LAR), chlorophyll a, b, and a+b content, and chlorophyll fluorescence (Fv / Fm, Fv / F0) were significantly elevated compared to plants growing in full sun. Leaf water status showed that leaf water potential-ψf decreased proportionally with the level of shading applied. Regarding the yield of stigmas, it was found that exposure of plants to 30% shade significantly improved the production of this spice.