MSc

The survey was conducted in Nedumangad taluk of Trivandrum
district with an intention to assess the extent of pink disease
incidence in rubber holdings extending upto 5 hectares in area.
The results obtained revealed that the pink disease caused by
Corticium salmonicolor (Berk. & Br.) is prevalent in all the 28
villages of Nedumangad taluk at varying intensities (1. 22 to 20.83%).
RRII 105 and RRIM 600 were the popular clones occupying the rubber
growing tracts of Nedumangad taluk. Among these clones, the intensity
and severity of the disease incidence was more for RRIM 600.
It was also observed that the plants of the age group 5 to 12
years were more prone to the disease than the younger and older
ones.
The rubber growers of Nedumangad taluk were found to be
aware of the symptoms and, management practices for the disease.
More than 85 per cent of the farmers had average or better knowledge
about the disease. They were found inspecting the plants regularly
for the disease incidence except for the few, who left the plants
undetected and untreated at the early stages of infection.
In the surveyed area the disease infection was found more
near the first fork region in both the clones studied. The farmers
were found to adopt surgical procedures and chemical treatment

for the control of the disease. Bordeaux paste was found more
popular among the growers than thiride, whereas calixin was not
at all used in Nedumangad. Efforts are to be taken to popularise
the use of calix in and thiride among the farmers. Recovery from
the disease was substantially good in the surveyed area. Early
detection and proper management could completely control the disease
to an extent of 96 per cent. The clone RRII 105 showed better
recovery than RRIM 600.
The survey also revealed the relative efficiency of the various
extension tools employed by the Rubber Board. Discussion with
extension officers was found to contribute the maximum in disseminat-
ing the knowledge about the disease. The farmers were also found
to rely upon the view of other growers indicating the control
measure to be adopted. The details collected during the survey
necessitates the need for further strengthening of the extension
work operated by the Rubber Board. The farmers preferred direct
field visit and discussion rather than conducting large scale seminars.
The urgent need for popularising of printing media like rubber
magazine among the farmers was also felt during the study.
To conclude, increased number of visit by the extension
officers of the Rubber Board and group discussions will help in
. disseminating the knowledge about the disease and help early
detection and treatment of pink disease of rubber in Nedumangad
taluk of Trivandrum district .