. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. MELAMPSORA 325 Pine branch twist.—The aecidium phase of Melampsora pinitorqua, ^ostxn^ {=Caeoma pinitorqiaan, A. Br.), has been shown by Hartig to be very destructive to young pines, seedlings being sometimes diseased as they appear above ground. About the age of thirteen the disease dies out, and those that have not been too severely attacked, recover. Plants that are attacked when quite young are usually killed,. Fig. ()Z.—Melampsora pinito?-qua. i, to
. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. MELAMPSORA 325 Pine branch twist.—The aecidium phase of Melampsora pinitorqua, ^ostxn^ {=Caeoma pinitorqiaan, A. Br.), has been shown by Hartig to be very destructive to young pines, seedlings being sometimes diseased as they appear above ground. About the age of thirteen the disease dies out, and those that have not been too severely attacked, recover. Plants that are attacked when quite young are usually killed,. Fig. ()Z.—Melampsora pinito?-qua. i, top of young pine attacked by the aecidium stage; 2, two chains of aecidiospores ; 3, aspen leaf with sori of teleutospores ; 4, section of cushion of teleutospores, still covered by the epidermis. Figs, i and 3 nat. size ; remainder mag. as the fungus appears year after year if damp weather prevails in May and June; this indicates that the fungus is peren- nial in the tissues of the host. In the seed-bed or young plantation the disease usually spreads from a centre, due to infection by wind-borne spores, showing that the aecidiospore stage is capable of perpetuat- ing the disease, without the intervention of another condi- tion of the fungus. Spermogonia and aecidia appear on the. 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 Massee, George, 1850-1917. New York : Macmillan
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Keywords: ., bookpublishernewyorkmacmillan, booksubjectplantdis, bookyear1910
