Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . FIG. 89. a, White clover leaf showing secidiuni stage; b, red clover leal showing uredo stages. Colorado, in the west. It is occasionallv so abundantas to injure seriously fields of red clover. Leaves affectedby the disease are more or less thickly covered withAvell-rlefined, oblong, brown powdery spots, as shown inFig. 89. 219 220 rUXGI AND FUXGICIDES Like various other members of the family of ruststo which this fungus belongs, it exists in three distinct
Fungi and fungicides; a practical manual, concerning the fungous diseases of cultivated plants and the means of preventing their ravages . FIG. 89. a, White clover leaf showing secidiuni stage; b, red clover leal showing uredo stages. Colorado, in the west. It is occasionallv so abundantas to injure seriously fields of red clover. Leaves affectedby the disease are more or less thickly covered withAvell-rlefined, oblong, brown powdery spots, as shown inFig. 89. 219 220 rUXGI AND FUXGICIDES Like various other members of the family of ruststo which this fungus belongs, it exists in three distinct. FIG. 90. CLOVER RUST, c, Cluster-cups and secidium spores; d, uredo spores;/, uredo pustule on cloverleaf; e, teleiito spores; fj, cross-section of stem showing mycelium betweencells; also two teleuto spores and one uredo spore. successive stages. Early in the season it appears—prin-cipally upon white clover plants—in the so-called cecid- THE CLOVER RUST . 221 ium stage. It affects both the leaves and stems, produc-ing cup-like swellings, which are filled with orangecolored spores. A white clover leaf attacked by thisstage of the fungus is shown in Fig. 89 a, while at c,Fig. 90, may be seen two of the cluster-cups magnified,and some of the orange colored spores still more orange spores are blown to other clover plants,especially red clover, where they germinate and sendtheir little tubes into the leaf tissues. These tubes startthe mycelium which develops between the leaf cells forsome time before any external indication of its presenceoccurs. Then it produces, at ce
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpathoge, bookyear1896
