Systemic Remissive Property of Metalaxyl Against Downy Mildew in Pearl Millet. S. D. Singh, Pearl Millet Improvement Program, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, P.O., A.P. 502 324, India. R. Gopinath, K. D. M. Luther, P. M. Reddy, and M. N. Pawar, Pearl Millet Improvement Program, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, P.O., A.P. 502 324, India. Plant Dis. 68:668-670. Accepted for publication 27 March 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-668.

Foliar application of metalaxyl effectively suppressed systemic downy mildew (DM) (Sclerospora graminicola) symptoms and healthy leaves and earheads were produced (recovery) on two susceptible pearl millet (Pennisetum americanum) cultivars, NHB-3 and 7042. A concentration of 31 ppm (a.i.) was effective for recovery of greenhouse plants, whereas for field-grown plants (DM nursery), a higher concentration (>63 ppm) was needed. Plant age at application did not affect recovery (7-to 35-day-old plants recovered), but earhead length for recovered plants was decreased if applications were made after panicle initiation. Recovered plants, both in the greenhouse and in the field, subsequently developed diseased nodal tillers and/or green earheads. The two cultivars showed similar recovery responses to foliar application of metalaxyl in the DM nursery, but seed treatment (2 g a.i./g) was more effective on NHB-3 than on 7042.