Volume 30 Number 1 Article 13 Pages: 14-15
Year 1976 Month 1
Title: Breeding Low-Chilling Deciduous Fruit Trees
Authors: W.B. Sherman and R.H. Sharpe
Citation
Abstract:
Rapid progress has been made in
breelhg temperate-climate fruits with
low winter-chilling requirements.
Genetic
clones of warm-winter adapted
temperate fruits have been collected
and tested in Florida for many years.
Breeding work at Gainesville was
started in 1950 on peaches, nectarines
and blueberries.
Other crops have
been added since.
Approx 40 professional
man-years have been devoted
to the breeding program at Gainesville.
Nearly 8000 commercial acres
of peaches and nectarines and 200
accres of blueberries have been planted
since 1965, largely as a result of
this research.
Other fruit tree crops
such as plum, pear and apple have
potential for dooryard and small plantings.
Low-chilling peach introductions of
the South China type, such as 'Jewel',
'Okinawa', 'Red Ceylon' and 'Hawiian'
were crossed with northern commercial
peaches and nectarines.
Chilling
requirements of the F1 hybrids were
intermediate and generally closer to
the lower chilling parent.
It has required
3 to 5 generations to obtain
early-ripening low-chilling commercial
types.
Approximately 34,000 peach
and 18,000 nectarine seedling have
been fruited.
Native Florida plums transmit their
small size and bitterness when crossed
with commercial Japanese forms.
Recent
progress has been made by crossing
low chilling P. salicina-type plums from Taiwan with commercial U.S. cultivars to produce acceptable flavor
and canker resistance.
Blueberries for warm winters have
resulted from crossing the native diploid
V. darrowi and hexaploid V. ashei
with each other and with northern
highbush cultivars.
It has required 25
years of hybridizing and over 160,000
seedlings to produce commercial types
of which 2 have been named.
Complications
include differences in ploidy
and resistance to stem canker.
Several hundred apples, reportedly
adapted to mild winters, were grafted
at Gainesville before 'Anna' was found
to be adapted.
Two selections have
been made from approximately 2000
seedlings with parentage similar to.
'Anna' and other Isareli types.
Approximately 900 pear seedlings
have given 3 low chilling selections
with some dessert quality.
These
should provide homeowners with considerable
improvement over local sand
pears.
Our main incentives for improvement
of temperate-climate fruits in
Florida are to provide early fresh fruit
for northern markets and for home and
local use in small farm and the urban
homeowners.
Low-chilling fruits from
our breedin program could be important
for the tropical highlands.
APS membership administration
ISHS membership administration
