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Disease Detection and Losses

Quantitative Disease Assessment of Wheat Seedling Leaves Inoculated with Fusarium roseum ' Culmorum' . J. P. Hill, Assistant professor, Department of Botany and Plant Pathology, Colorado State University, Fort Collins 80523; Phytopathology 74:665-667. Accepted for publication 1 February 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-665.

Wheat seedling leaves were wounded and inoculated with agar disks containing microconidia of Fusarium roseum ' Culmorum.' Seedlings were grown in a growth chamber under moisture stress conditions of - 5 or - 10 bars for 3 wk before inoculation. Relative comparisons between cultivar pairs were made by measuring lesion length 1 wk after inoculation. There were no differences in lesion size among seedlings of the same cultivar grown under the two different soil matric potentials. Significant lesion size differences occurred between cultivars in all paired comparisons when seedlings were grown under moisture stress and lesions were measured 7 days after inoculation. This quantitative method of measuring disease reaction between wheat cultivars may be useful in identifying general resistance (horizontal resistance sensu Vanderplank). Identification of general resistance could significantly aid breeders in selecting for increased resistance to Fusarium foot or root rot of wheat.