Botryodiplodia sp. - Crops for the Future

The cross-inoculation experiment with Annona muricata fruits did not lead to satisfactory
results. The reason being that the severity of infection in the two controls were the same or
higher to the severity caused by the pathogens. A statistically significant higher severity
between pathogen taken from Annona muricata and the one taken from Annona squamosa
compared to the others can be seen at the fifth day.
The variability in the cross-inoculation experiment with Annona squamosa fruits was high;
nevertheless we can conclude that the pathogens of the various fruits do infect the others.
Sporulation experiment:
The treatment with a cold shock resulted in the longest sporulation times of 26 days with
respect to all pathogens which were observed; the pathogen isolated from a red skinned
Annona squamosa which did not sporulate during the experimental period. The pathogens
which were isolated from rambutan and Annona squamosa sporulated fastest (15 days) under
the daylight treatment. The pathogens isolated from the red skinned Annona squamosa and
from Annona muricata sporulated fastest (24 days) in the incubator without any treatment.
The two collaborative Institutes are described in this report as well as the country. Characteristics
of both fruits used for the experiments and other important Annona species (A. cherimola and A.
reticulata) as well as the two fungi are also described.
2 Introduction
The background for the research presented here was the “Berufspraktisches Projeksemester”
(BPS) programme which has to be done as a practical part of the author’s studies towards a
Bachelor of Science degree in Horticulture-Management.
The work was done in two institutes in Sri Lanka: The International Centre for Underutilised
Crops (ICUC) which has announced the internship and the Industrial Technology Institute
(ITI) which was the main working place for the experimental trails.
The Intern was involved in a project of ITI and conducted several experiments which are
described on the following pages.
The main task of the intern was to prove antagonistic effects of fungus (Trichoderma sp.)
against a fungal pathogen (Botryodiplodia sp.).
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