Disease Resistance and Yield Loss to Sugarcane Mosaic Virus in East African‐adapted Maize1

Maize (Zea mays L.) inbreds, cultivars, and hybrids 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 S1 plants from field selections continued to demonstrate resistance to SCMV. S2 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 SCMV‐Kit and SCMV‐Mug. When mechanically inoculated with SCMV‐Kit, 10 Kenyan hybrids had yield losses that varied from 18 to 46%. Yield losses varied significantly by hybrid but not tune of inoculation. The interaction of hybrid X time of inoculation was not significant for yield. Tolerant hybrids, such as H614C, H611(R)C5, H612C, H5020, or EAH6302, are recommended in areas of East Africa where SCMV is prevalent.