1.- To measure daily dynamics of photosynthesis, respiration of leaves and roots, NSC and dry mass accumulation of all plant organs and whole plant net carbon exchange of three herbaceous and three woody horticultural crops with different phloem loading mechanisms submitted to contrasting sink demands 2.- To study the relationship between excess leaf NSC inventories and carbon assimilation and growth of three herbaceous and three woody horticultural crops with different phloem loading mechanisms submitted to contrasting sink demands. 3.- To estimate carbon, light, nitrogen and water use efficiencies of three herbaceous and three woody horticultural crops with different phloem loading mechanisms submitted to contrasting sink demands. 4.- To adjust a single whole plant carbon balance model to three herbaceous and three woody horticultural crops with different phloem loading mechanisms and using the model to quantify the relative contribution of phloem loading mechanism and sink demand to the control of carbon assimilation and growth and for simulating the effect of exchanging the phloem loading mechanism between crops on carbon assimilation and growth.