Table 5.
Distribution of three viruses detected in cultivated yams within four agro-ecological zones in Cameroon
| Agro-ecological zone | Yam species | Farms sampleda | Samples tested | Viruses detected (%) | ||||
|---|---|---|---|---|---|---|---|---|
| YMV | YMMV | CMV | YMV + YMMV | Total | ||||
|
Zone II: high guinea savannah |
D. alata | 8 | 25 | 12.5 | 0 | 0 | 37.5 | |
| D. cayenensis | 8 | 50 | 12.5 | 0 | 0 | 62.5 | ||
| D. dumetorum | 1 | 0 | 0 | 0 | 0 | 0 | ||
| D. rotundata | 132 | 28.8 | 2.3 | 0 | 0 | 31.1 | ||
| Total | 31(64.5) | 149 | 29.5 | 3.4 | 0 | 0 | 32.9 | |
| Zone III: western highlands | D. alata | 10 | 20 | 20 | 0 | 0 | 40 | |
| D. bulbifera | 4 | 0 | 0 | 0 | 0 | 0 | ||
| D. cayenensis | 88 | 47.7 | 1.1 | 0 | 0 | 48.9 | ||
| D. dumetorum | 18 | 0 | 0 | 0 | 0 | 0 | ||
| D. rotundata | 25 | 28 | 0 | 0 | 0 | 28 | ||
| Total | 31(74.2) | 145 | 35.2 | 2.1 | 0 | 0 | 37.3 | |
|
Zone IV: humid forest with monomodal rainfall |
D. alata | 17 | 11.8 | 0 | 0 | 0 | 11.8 | |
| D. bulbifera | 1 | 0 | 0 | 0 | 0 | 0 | ||
| D. cayenensis | 4 | 75 | 0 | 0 | 0 | 75 | ||
| D. dumetorum | 34 | 8.8 | 17.8 | 0 | 0 | 26.5 | ||
| D. rotundata | 93 | 48.4 | 0 | 0 | 0 | 48.4 | ||
| Total | 31(83.9) | 149 | 35.6 | 4.0 | 0 | 0 | 39.6 | |
|
Zone V: humid forest with bimodal rainfall |
D. alata | 22 | 27.3 | 13.6 | 0 | 0 | 40.9 | |
| D. cayenensis | 48 | 41.7 | 4.2 | 0 | 12.5 | 58.4 | ||
| D. dumetorum | 4 | 50 | 0 | 0 | 0 | 50 | ||
| D. rotundata | 74 | 17.6 | 5.4 | 0 | 2.7 | 25.7 | ||
| Total | 31(77.4) | 148 | 27.7 | 6.1 | 0 | 5.4 | 39.2 | |
| Total | 124(75) | 591 | 31.9 | 3.9 | 0 | 1.4 | 37.2 | |
aNumber of farms sampled (percentage of virus-positive farms given in parenthesis)