Sap activity, which transforms excess ingested sugar into long-chain oligosaccharides." A much larger set of animals do however consume phloem sap by proxy, either "through feeding on the honeydew of phloem-feeding hemipterans. Honeydew is physiologically less extreme than phloem sap, with a higher essential:non-essential amino acid ratio and lower osmotic pressure," or by feeding on the biomass of insects that have grown on more direct ingestion of phloem sap. Maple syrup is made from reduced sugar maple xylem sap. The sap often is harvested from the Sugar Maple, "Acer saccharum". In some countries (e.g., Lithuania, Latvia, Estonia, Finland, Belarus, Russia) harvesting
Plant hormone propagation from cuttings, grafting, micropropagation, and tissue culture. The propagation of plants by cuttings of fully developed leaves, stems, or roots is performed by gardeners utilizing auxin as a rooting compound applied to the cut surface; the auxins are taken into the plant and promote root initiation. In grafting, auxin promotes callus tissue formation, which joins the surfaces of the graft together. In micropropagation, different PGRs are used to promote multiplication and then rooting of new plantlets. In the tissue-culturing of plant cells, PGRs are used to produce callus growth, multiplication, and rooting. Plant hormones affect seed germination and dormancy