dc.contributor.author | Ikahu, J. M. K | |
dc.date.accessioned | 2013-05-15T11:55:06Z | |
dc.date.available | 2013-05-15T11:55:06Z | |
dc.date.issued | 1987 | |
dc.identifier.citation | Ikahu, J. M. K(1987). Phenotypic variation in floral development and pyrethrin content in genetically different clones of pyrethrum chrysanthemum cinerariefolium vis | en |
dc.identifier.uri | http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/23191 | |
dc.description | Msc Thesis | en |
dc.description.abstract | Pyrethrum, Chrysanthemum cinerariae folium
vis, is an important insecticide producing plant
propagated vegetatively by splits and shoot cuttings.
The objectives of the study were to determine
the pattern of pyrethrins and dry weight net
accumulation during the entire flowering cycle, the
duration of transition in days from one stage to
the other during the flowering cycle and to determine
the optimum picking time for six recommended
pyrethrum clones (Ma/70/1013, Ma/71/423, 4331, SB/
66/107, Ks/71/6 and Ks/70/64. The experiment was
laid out in split-plot block design with three replicates.
During the 1985/86 growing season three
plants from each fully establi~hed clone were randomly
selected and labelled. From each plant three
flower heads were randomly selected and labelled
at bud stage. The date when the selected bud had
just started to open was noted and the number of
days from there on to reach each of the eight stages
of development were counted in each clone. Sampling
for dry weight and pyrethrins content was done
January, June and September
There were highly significant differences
arnon gs L t.h o cLon os in pyre t hr Lns CUll Len Land 100
flower dry weight at different stages of flower
development. Lack of interaction between clones
and developmental stages in both pyrethrins content
and 100 flower dry weight suggested the pattern
of dry weight and pyrethrins net accumulation
was similar in all pyrethrum clones.
The 100 flower dry weight increased from
closed bud (Stage I) and reached a maximum at the
late overblown stage (Stage VII) in all the clones.
The pyrethrins in the flower head generally increased
from closed bud (Stage I) to a maximum when
nearly all disc florets were open (Stage V) in all
the clones except clone Ma/71/423 which had a maximum
pyrethrins content at Stage IV. The pyrethrins
yield increased from a closed bud (Stage I) to u
maximum at Stage VI in clones Ks/70/64 and Mu/71/423
while clones SB/66/107, Ks/71/6 and Ma/70/1013 had
a maximum pyrethrins yield in Stage VII. Clone
4331 showed slight changes in pyrethrins yield
from Stage V to VII. The time lapsed from closed
bud (Stage I) to nearly all disc florets open
(Stage V) when most of the clones had maximum pyrcthrins
content varied from 18 to 21.2 days except
for clone 4331 which varied from 11 to 19.5 days.
Results suggested that the optimum picking
stage for clones SO/66/107, Ma/70/101~Ks/71/6
should be in Stage" VI, while clones Ks/70/64 and
Ma/71/423 in Stage V. Clone 4331 can be picked
in Stage IV to VII as it showed very slight
changes during these stages. | en |
dc.description.sponsorship | University of Nairobi | en |
dc.language.iso | en | en |
dc.subject | Phenotypic variation | en |
dc.subject | Floral development | en |
dc.subject | Pyrethrin content | en |
dc.subject | Chrysanthemum cinerariefolium vis | en |
dc.subject | Clones | en |
dc.subject | Pyrethrum | en |
dc.title | Phenotypic variation in floral development and pyrethrin content in genetically different clones of pyrethrum chrysanthemum cinerariefolium vis | en |
dc.type | Thesis | en |
local.publisher | Department of Plant Science and Crop Protection, University of Nairobi | en |