. Manual of fruit diseases . Fruit. BLACKBERRY DISEASES 167 But the successive activities of Scptoria Riibi have not been care- fully studied ; this is probably due to the fact that the disease which it produces has never been of great economic importance. The mycelium of the fungus growing in local areas within the leaf-tissues causes the color changes and finally their death. The fungus forms fruit- ing bodies — pycnidia — just beneath the upper surface of the cuticle. These, as the^' mature, break through the cuti- cle and stand exposed over the affected area. Within the pycnidia spores are
. Manual of fruit diseases . Fruit. BLACKBERRY DISEASES 167 But the successive activities of Scptoria Riibi have not been care- fully studied ; this is probably due to the fact that the disease which it produces has never been of great economic importance. The mycelium of the fungus growing in local areas within the leaf-tissues causes the color changes and finally their death. The fungus forms fruit- ing bodies — pycnidia — just beneath the upper surface of the cuticle. These, as the^' mature, break through the cuti- cle and stand exposed over the affected area. Within the pycnidia spores are developed which at maturity, under moist weather condi- tions, ooze out and are scattered to other leaves. Here they germinate in water and the result is a germtube which in some way gets into the leaf-tissues. A spot is the outcome. Little Is known of the winter condition and of the manner in which the first infections in the spring are brought about. Control. In cases in which the leaf-spot disease becomes a menace it may be kept in check fairly well by the use of bordeaux mixture, 4—5-50, or lime-sulfur 1-50. The spray should be applied as follows: (1) shortly after the leaf-buds unfold, (2) subsequent applications at intervals of two to three weeks until the fruit is about two-thirds Fig. 46. — Blackberry 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 Hesler, L. R. (Lexemuel Ray); Whetzel, Herbert Hice, 1877-1944. New York : Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1917
