. Plant propagation : greenhouse and nursery practice . Plant propagation. GERMINATION 27 excess moisture tends to weakening and damping-oli' (78) of seedlings. 45. Aids to germination.—Most seeds properly handled germinate freely; but seeds of certain families, the Um- belliferse especially, are slow (parsley, carrot, celery, parsnip, etc.). These and hard, bony seeds (48) allowed to dry out too much may fail entirely unless treated prior to sowing. Their treatment seeks to soften or break the seed coats so the embryos may emerge. 46. Enzymes used experimentally in some cases increased the pe
. Plant propagation : greenhouse and nursery practice . Plant propagation. GERMINATION 27 excess moisture tends to weakening and damping-oli' (78) of seedlings. 45. Aids to germination.—Most seeds properly handled germinate freely; but seeds of certain families, the Um- belliferse especially, are slow (parsley, carrot, celery, parsnip, etc.). These and hard, bony seeds (48) allowed to dry out too much may fail entirely unless treated prior to sowing. Their treatment seeks to soften or break the seed coats so the embryos may emerge. 46. Enzymes used experimentally in some cases increased the per- centage of germination when the seeds were soaked several hours in a solution of some active enzyme or enzymes; the vigor of the young plantlets was often enhanced at the same time ; within limits these good effects increase with the strength of the solution; diastase seems to be the most useful; tomato seeds seem to respond es- pecially well to diastase. 47. Chemicals, usually di- lute, or weak acids or alkalies, are sometimes used for seeds with hard, bony coats affected neither by soaking nor freez- ing. They soften the shells so water may enter. Vinegar aids the seeds of bramlile fruits (blackberry, raspberry, etc.). Sulphuric acid (com- mercial strength) is some- times used for cotton, alfalfa and clover seeds, the soaking lasting two or three to CO min- (Fig. 21). Thorough ::^ './ith water '.:r ih: S(jaking is essential. Great care must be exercised in diluting the acid. The acid may be poured slowly into the full volume 1 f \v:itcr. Init the reverse order must not l)c followed because the acid will "; The acid must not touch the skin or fabrics, because it FIG. 21—KENTUCKY COFFEE TRCE S2CD! ING Ifhuric acid mad^ fhis develop- ment in 40 Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not per
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Keywords: ., boo, bookcentury1900, bookdecade1910, booksubjectplantpropagation
