Botryodiplodia sp. - Crops for the Future

The experiment was carried out on rambutan, sugar apple and soursop fruits and repeated.
In every experimental trial four pathogens were tested on ten fruits and two different controls
were undertaken, in which likewise ten fruits were used. So that in total 60 fruits were
necessary for one experimental series. The soursops and sugar apples were bought from local
markets in Colombo whereas the rambutan fruits were picked direct from a rambutan
plantation. The experiments undertaken with rambutan were only done with fruits of the
variety `Malwana Special´.
At the beginning of the experiments the fruits had to be surface sterilized to avoid field
inoculations. Therefore the fruits were dipped for five minutes into a 5 % sodium
hypochlorite solution. After drying the fruits on air in the laminar flow cabinet one well was
cut near the stem by using a cork borer (No. 5). It was important that the well was not cut too
deep into the fruit at best only the skin should be removed. Than a seven day old mycelia disk
of the pathogen was insert into the well.
In the first control (control 1) the wells were filled with distilled water whereas the second
control (control 2) consisted out of untreated fruits.
All fruits where stored in self-made humidity chambers (Figure 27) during the experimental
time of six days. An observation of the fruits was undertaken daily which gathered the disease
spread in percent by using an infestation key (Figure 28 and Figure 29).
Figure 27: Humidity chamber for the rambutan
Cross-inoculation experiment
Figure 28: Infestation key for crossinoculation
experiment with sugar apple
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