. Diseases of plants in the United States in 1939. Crop losses United States; Plant diseases United States. 232. Fig, 21. Estimated percentage losses from leaf rust of v;heat in 1939. greatest loss, 2 percent, was reported in Virginia which is less than for several years. In West Vii^ginia the loss was estimated at 1 per- cent, elsewhere it was negligible. In i'linnesota, J, J. Christensen reported a "Decrease in loss because nearly all spring wheat in Minnesota is ; C. A. Suneson, in the Vfestern Region, said, "Stem rust, widespread and severe over much of the region l
. Diseases of plants in the United States in 1939. Crop losses United States; Plant diseases United States. 232. Fig, 21. Estimated percentage losses from leaf rust of v;heat in 1939. greatest loss, 2 percent, was reported in Virginia which is less than for several years. In West Vii^ginia the loss was estimated at 1 per- cent, elsewhere it was negligible. In i'linnesota, J, J. Christensen reported a "Decrease in loss because nearly all spring wheat in Minnesota is ; C. A. Suneson, in the Vfestern Region, said, "Stem rust, widespread and severe over much of the region last year, was not even seen outside California this year" (PDR 23:283). P. rubigo-vera tritici,leaf rust, was reported generally less or much less prevalent (Fig. 21) than in 1938. Early infections were light as compared to last year. In some States leaf rust was present in every field but did not much progress, ovdng to the dry weather. In Illinois, the Natural History Survey reported the maximum infection in any one field "ICO percent of plants and percent of leaf area. Average prevalence, 100 percent of plants, and 28,9 percent of leaf ; C. 0. Johnston, in Kansas reported (PDR 22:463) that despite the drought considerable' lea:f rust infection was observed on volunteer wheat in the fall of 1938, which probably originated from ovorsummering urediospores rather than from spores blown in from the North. Later, (PDR 23:75) low^ temperatures and dry weather drastically reduced the amount of overwintering with the result that in 1939 heavy infections did not develop until late in the season, and since unfavorable weather conditions ripened most of the wheat before severe damage was done, heavy losses occurred only on late wheat in the north central part of the State. Leaf rust ovei''.\dntered in California, but apparently did not do any d? Please note that these images are extracted from scanned page images that may have been d
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