ABACA Activities in the Philippines - Unido

Ref. No. CFC/FIGHF/09 CFC/UNIDO/FIDA 42
4.3.1 For the bunchy-top trial
In Albay, results of the screening trial showed that all the varieties had very low disease incidence
during the first nine (9) months and slowly increased 14 months after. Tangongon has the highest disease
incidence followed by Lausigon and Laguis. Maguindanao was the last variety which succumbed to the
disease and had the least AUDPC while the rest of the varieties exhibited varying degrees of infection. The
growth stage of the abaca plant was severely affected by bunchy-top infection as shown by the delayed sword
sucker stage on the 9 th month instead of maiden to palm sucker stage (Fig 10).
Fig 10. Disease progress curve of bunchy-top infection on
eight selected varieties 31 MAP screened in Albay
In Davao, although eight (8) varieties were planted in Bago-Oshiro, survival rate of the Bicol
varieties were low which resulted to high mortality. Thus, the trial proceeded with six varities only namely,
Linawaan, Laguis, Inosa, Maguindanao, Tangongon and Musa tex 51. Unlike in Albay, the eight varieties
varied in their reaction to bunchy-top disease. Symptom appearance was delayed for almost nine months from
which disease incidence occurred only on the 14 th month. However, the infection in Davao was almost similar
to Albay with Musa Tex 51 having 41.35% infection while Tangongon in Albay had 45.66% (Fig. 11).
Fig. 11. Disease progress curve of bunchy-top infection on
six (6) selected varieties screened in Davao
Incidence of bunchy-top on eight (8) varieties and the factors which contributed to the severity of
infection 31 months after planting were analyzed with regression analysis. Computed r 2 for the factors which
determined percent disease incidence such as infection rate, AUDPC, incubation time in both location were