Whitefly and whitefly-borne viruses in the tropics : Building a ... - cgiar

Progress of Cassava Mosaic Disease in Single and Mixed Stands
the mixture than in the pure stand.
However, there was no evidence of a
barrier or edge effect using SS4 and the
comparison may have been vitiated by
the extent of cutting infection with Bao.
A further difficulty is that Bao is a tall
Incidence of CMD (%)
Incidence of CMD (MIU)
100
80
60
40
20
0
100
80
60
40
20
0
100
80
60
40
20
0
800
600
400
200
0
0(M)
Migyera Migyera
Nase 2 Nase 2
Ebwanateraka
1(Ju)
2(Jy)
3(A)
4(S)
5(O)
6(N)
7(D)
8(Ja)
Figure 3. Mean monthly incidence of cassava mosaic disease (CMD, %) in successive months after
planting in varieties Migyera, Nase 2 and Ebwanateraka when grown alone and as a
mixture at Namulonge in (left) the 1995-96 and (right) the 1996-97 experiments. Incidence
data for Ebwanateraka were transformed to multiple infection units (MIU) in the bottom two
figures.
0(O)
Ebwanateraka
Ebwanateraka Ebwanateraka
erect variety that outgrows SS4, which is
a relatively low spreading type. This
suggests that varieties of similar habit
and conformation should be selected for
any further evaluation of mixtures.
1(N)
2(D)
3(Ja)
4(F)
MAP MAP
Grown alone In varietal mixture
5(M)
6(A)
7(M)
8(Ju)
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