A Seedling Inoculation Technique for Detecting Downy Mildew Resistance in Pearl Millet. S. D. Singh, Plant Pathologist, Pearl Millet Improvement Program, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru P.O., A.P. 502 324, India. R. Gopinath, Research Associate, Pearl Millet Improvement Program, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru P.O., A.P. 502 324, India. Plant Dis. 69:582-584. Accepted for publication 27 August 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-582.

A seedling inoculation technique that produces consistently heavy downy mildew (Sclerospora graminicola) infection (≥85%) on susceptible pearl millet cultivars is described. It involves inoculation of seedlings in pots with an aqueous suspension of sporangia applied by a microsyringe. The greatest downy mildew infection occurred in seedlings inoculated before the first leaf unfolded and sharply decreased when the seedlings were inoculated at a later stage. The technique, which is more effective than field inoculation in producing downy mildew, resembles natural inoculation but allows inoculum uniformity and does not affect normal host activity. It is valuable for checking the reliability of field-identified resistance and for detecting high levels of resistance in key material.