CMD (cassava mosaic virus disease): The number of shoot tips (young flushes with at least five opened leaves) was counted and disease severity was rated for each of the tips. A scale of 1–5 was used to assess severity: 1=no symptom; 2=mild chlorotic patterns and slight distortion of only the base of leaves; 3=mosaic patterns on all leaves, leaf distortion; 4=mosaic patterns on all leaves, leaf distortion, and general reduction in leaf size; 5=leaves twisted/misshapen and stunting of whole plant. Means of shoot tip severities per plant were used in the analysis.