Infestation densities of the pine woolly aphid (pineus pini) on pinus patula as related to site productivity at Sao hill forest plantation
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Date
1990
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine University of Agriculture
Abstract
Between September
carried out
Sao
at
Hill
1989
March,
and
1988
a
plantation
forest
study was
with the
following major objectives
- to examine the relationship between Pinus patula stand
productivity and abundance of the Pineus pini.
- to elucidate the impact of P. pini on tree growth.
Based
on
a
preliminary
main
the
sampling,
sampling
intensity was determined for a fixed degree of precision. In the
main sampling, the two site classes I and III and
the young
class
age
compartments
100 infested
sampled
were
classes. In each
(<10
years)
in
compartment,
trees had
sampled. Three
were
each
the
of
two
site
continued until
sampling
been recorded. For each infested
tree, a 10 cm long twig was pruned from the
middle crown
crawlers and adult aphids were observed and
whorl. Eggs,
counts made under a dissecting microscope. In the
main sampling, the two site classes I and III and
the young
class
age
compartments
100 infested
sampled
were
classes. In each
(<10
years)
in
compartment,
trees had
sampled. Three
were
each
the
of
two
site
continued until
sampling
been recorded. For each infested
tree, a 10 cm long twig was pruned from the
middle crown
crawlers and adult aphids were observed and
whorl. Eggs,
counts made under a dissecting microscope.
An infestation experiment
growth impact
of P.
was
established
to elucidate
pini infestation on young P. patula
seedlings after 24 weeks of growth.
The main findings of the study were that:Population densities were higher in trees of poor sites
compared to trees of
infested
trees
were
good sites.
equally
The percentages
high
of
at both good-
Description
Dissertation
Keywords
Pine woolly, Sao hill, Forest Plantation, Pinus patula, Pineus pini