Evaluation of newly developed pearl millet varieties [Pennisetum glaucum (L).R. Br] for reactions to Downy Mildew, Stem Borer and Striga hermonthica under natural field conditions in Northern Nigeria

Abstract

Pearl millet [Pennisetum glaucum (L.) R. Br.] varieties – SOSAT-C88 (newly released in Nigeria) and LCIC 9702 (about to be released) were evaluated under natural infestation in 53 farmers’ fields in five states of Northern Nigeria during 1999 for reactions to downy mildew [Sclerospora graminicola (Sacc.) J. Schrot.], parasitic weed Striga hermonthica and pearl millet stem borer [Coniesta ignefusalis Hampson].  The objectives of the survey were to assess the effects of these biotic constraints on the new varieties to prioritize areas for future improvement in order to enhance adoption process.  Our study reveals that SOSAT-C88 appears to be resistant to downy mildew not only in on-station experiments but also in farmers’ field conditions.  This variety could serve as potential source parent for transfer of downy mildew resistance genes to elite materials or as a resistant check in downy mildew screening experiments.  However, SOSAT-C88 seems to be susceptible to S. hermonthica in the two test environments.  Babura, Ajiwa and Kamba were endemic to S. hermonthica on pearl millet.  These locations could be useful as hot sports for screening pearl millet lines for resistance studies under natural infestations.  LCIC 9702 appears to tolerate these diseases while local cultivars are highly susceptible to downy mildew but tolerant to Striga and stem borer.  Incidence of pearl millet stem borer was lower than expected; this could probably be due to adoption by farmers of early sowing practices and burning of millet stem before the commencement of rains in most locations.  More information is needed on the reactions of SOSAT-C88 to downy mildew in order to fully ascertain the stability of the resistance over time and space.  Also the performance of SOSAT-C88 under artificial infestation of Striga should be further investigated.  Intercropping systems was the dominant practices and two and three crop mixtures were prevalent in all the states surveyed.