Disease Resistance and Yield Loss to Sugarcane Mosaic Virus In East Mrican-adapted Maize1

Abstract

Maize (Tea mays L.) inbreds, cultivars, and hyhrids were tested for resistance to two Kenya isolates of sugarcane mosaic virus (SCMV-Kit and SCMV-Mug) _ Sixteen out of 4,380 plants representing 8 of 71 entries were resistant. Five S, plants from field selections continued to demonstrate resistance to SCMV. S. plants from Philippine DMR-5 mechanically inoculated with SCMV-Kit and SCMV-Mug appeared highly resistant or tolerant. Pa405, a U.S.-adapted inbred, was also resistant to SCMVKit and SCMV-Mug. When mechanically inoculated with SCMV-Kit, 10 Kenyan hybrids had yield losses that varied 1 from 18 to 46%. Yield losses varied significantly by hybrid but not time of inoculation. The interaction of hybrid X time of inoculation was not significant for yield. Tolerant hybrids, such as H6HC, H6U(R) C5, H612C, H5020, or EAH6302, are recommended in areas of East Africa where SCMV is prevalent.