. Botany, with agricultural applications. Botany. 400 THALLOPHYTES thought that the basidiospores started the disease directly on the Grass host, but experiments have shown that they will not grow on this host. Experiments have also shown that urediniospores are ordinarily killed by freezing weather and therefore are rarely able to live over winter where the temperature goes much below freezing. It has been suggested that some hyphae may enter the kernels of the diseased plants and remain dormant until the seed is planted and then infect the seedling, but this theory is not generally accepted.
. Botany, with agricultural applications. Botany. 400 THALLOPHYTES thought that the basidiospores started the disease directly on the Grass host, but experiments have shown that they will not grow on this host. Experiments have also shown that urediniospores are ordinarily killed by freezing weather and therefore are rarely able to live over winter where the temperature goes much below freezing. It has been suggested that some hyphae may enter the kernels of the diseased plants and remain dormant until the seed is planted and then infect the seedling, but this theory is not generally accepted. Another suggestion is that the wind carries the urediniospores northward from the Southern states where they rrtrffV"'"''. Fig. 358. — Apple affected with Cedar Rust. From Technical Bulletin 9, Virginia Agr. Ejcp. Sta. are able to live over winter. It is also probable that the aecio- spores may be carried a considerable distance by the wind and thus reach grain fields not in the immediate vicinity of Barberry bushes. Then there is the probability that the disease may start on the wild Grasses growing near the Barberry bushes, and be passed along by the urediniospores from one patch of Grass to an- other until grain fields far away are reached. No satisfactory preventative for the Black Rust has been dis- covered. We are not able to control the spores. It is generally believed that the eradication of all of the Common Barberry bushes would do much toward ehminating this Rust. The most. 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 Martin, John N. (John Nathan), b. 1875. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1920
