The influence of low temperature treatment on dormancy release, growth and flowering of strawberry (fragaria x ananasa. Duch.
Abstract
This study was conducted to investigate the effects of
artificial low temperature treatment in overcoming bud dormancy
and promoting vegetative growth, runner production and flowering
in two strawberry cultivars 'Pajaro' and 'Douglas·. In the first
study, cultivar 'Douglas' was grown both in Thika and Limuru
whereas cultivar 'Pajaro' and ~Douglas' in the second study were
grown only in Limuru.
Low temperature treatment at 3-50 C promoted dormancy
release and vegetative growth. 'Pajaro' showed better growth
response to chilling than -Douglas' in Limuru. The number of
runners, runner plants, runner series, petiole length and leaf
area increased with increasing duration of cold treatment.
Branch crown development and flower production was lower with
increasing duration of cold treatment. Vegetative growth was
more vigorous in Thika than in Limuru. Cold treated -Douglas'
plants produced significantly more runner plants in Thika than
in Limuru. In contrast, the number of branch crowns produced was
higher in Limuru than in Thika. Cold treatment resulted in early
and increased production of runners and runner plants. Those
plants which received no chilling or one month of low
temperature treatment produced few runners which produced very
few runner plants or failed to produce any. Runner elongation
This study was conducted to investigate the effects of
artificial low temperature treatment in overcoming bud dormancy
and promoting vegetative growth, runner production and flowering
in two strawberry cultivars 'Pajaro' and 'Douglas·. In the first
study, cultivar ~Douglas' was grown both in Thika and Limuru
whereas cultivar 'Pajaro' and 'Douglas' in the second study were
grown only in Limuru.
Low temperature treatment at 3-50 C promoted dormancy
release and vegetative growth. 'Pajaro' showed better growth
response to chilling than 'Douglas' in Limuru. The number of
runners, runner plants, runner series, petiole length and leaf
area increased with increasing duration of cold treatment.
Branch crown development and flower production was lower with
increasing duration of cold treatment. Vegetative growth was
more vigorous in Thika than in Limuru. Cold treated Douglas'
plants produced significantly more runner plants in Thika than
in Limuru. In contrast, the number of branch crowns produced was
higher in Limuru than in Thika. Cold treatment resulted in early
and increased production of runners and runner plants. Those
plants which received no chilling or one month of low
temperature treatment produced few runners which produced very
few runner plants or failed to produce any. Runner elongation
and production of runner series were also stimulated by
chilling. Petiole length and leaf area increased with increasing
duration of cold treatment. Unchilled plants produced small
leaves with short petioles. The petiole length and leaf area
increased reaching a maximum at 120 days from transplanting and
then started decreasing. There were no significant differences
among treatments in petiole length and leaf area at 50 days
and after from transplanting. The number of branch crowns
produced were inversely proportional to the duration of cold
treatment. Unchilled plants and those which received one month
of chilling were characterized by increased branch crown
development. The number of branch crowns increased rapidly after
150 days from transplanting in all treatments.
'Low temperature treatment increased early flower
production from the terminal bud and vigorous flower development
upto 30 days from transplanting. Unchilled plants flowered
profusely in the field all the time. The number of flower
clusters produced after 30 days from transplanting were less
with increasing duration of cold treatment. Unchilled plants and
those which received one month of low temperature treatment
produced more flower clusters than those plants which were
chilled for two and three months. Flower production also
increased rapidly after 150 days from transplanting in all the
treatments due to dormancy resumption. Many flower clusters were
initiated from the many branch crowns formed in plants in both
sites.
Citation
Master of Science in HorticulturePublisher
University of Nairobi Faculty of Agriculture, University of Nairobi