Diseases of flowers and other Diseases of flowers and other ornamentals diseasesofflower118smit Year: 1940 Fig. 26.—Black spot of rose. plants. The same organism—Phytomonas tumefaciens—is responsible. In the rose it sometimes also happens that similar galls appear on the stems aboveground, usually at nodes or points where injuries have occurred. In some cases in greenhouse roses, large, soft, spongy galls develop in abundance in the stems wherever there has been a cut. Care should be taken not to plant rose bushes affected with crown gall. Badly diseased plants should be removed and burned.
Diseases of flowers and other Diseases of flowers and other ornamentals diseasesofflower118smit Year: 1940 Fig. 26.—Black spot of rose. plants. The same organism—Phytomonas tumefaciens—is responsible. In the rose it sometimes also happens that similar galls appear on the stems aboveground, usually at nodes or points where injuries have occurred. In some cases in greenhouse roses, large, soft, spongy galls develop in abundance in the stems wherever there has been a cut. Care should be taken not to plant rose bushes affected with crown gall. Badly diseased plants should be removed and burned. In the case of bushes which are affected in the canes aboveground, it may be possible to cut off the diseased branches and force out new growth if the galls are not too abundant. All cuts, as well as the tools, should be disinfected with 1-1,000 solution of corrosive sublimate (p. 100). Downy Mildew.—Irregular brown spots are sometimes seen on the younger leaves, with a sparse fungus growth, Peronospora sparsa, on the underside. The leaves are blighted and often fall. This disease is not
Size: 1527px × 1310px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
