. The cotton plant in Egypt, studies in physiology and genetics. Cotton; Cotton. VII NATURAL CROSSING 117 Prevention.—The evidence as to the means by which the cross-pollination takes place is not yet as full as we should like it to be, l)ut the greater part is performed by bees. Tests for wind-blown pollen made by the author with glycerine smears on glass plates have given negative results on the breeding plot, though a cm-tain amount of pollen must be dislodged in this way in close-sown field. Fill. 51. —Netted Plants. First ci'dSiSes and parents. crop.* Tiie remedy, therefore, seems to lie
. The cotton plant in Egypt, studies in physiology and genetics. Cotton; Cotton. VII NATURAL CROSSING 117 Prevention.—The evidence as to the means by which the cross-pollination takes place is not yet as full as we should like it to be, l)ut the greater part is performed by bees. Tests for wind-blown pollen made by the author with glycerine smears on glass plates have given negative results on the breeding plot, though a cm-tain amount of pollen must be dislodged in this way in close-sown field. Fill. 51. —Netted Plants. First ci'dSiSes and parents. crop.* Tiie remedy, therefore, seems to lie in the exclusion of bees from the flower. In most countries this can be done by covering the flowers with paper bags, but the method fails in Egypt, since about 95 per cent, of the flowers thus treated are promptly shed ; this shedding appears to be due to the local interference with transpira- tion, and consec[uent over-heating of the tissues. We have therefore employed mosc|uito-nets, which cover the whole plant, being supported over it on four posts. (Fig. 51). Pi'aetically no vicinism then takes place, though * See Allard, H. A. (2).. 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 perfectly resemble the original Balls, William Lawrence, 1882-. London, Macmillan and Co. , Ltd.
Size: 2007px × 1245px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1912
