Volume 30 Number 1 Article 28 Pages: 26-26
Year 1976 Month 1
Title: Essential Characters for Machine Harvest of Strawberries
Author: E.L. Denisen
Citation
Abstract:
Plant adaptation to mechanization
of the strawberry harvest is predicated
on the premise that breeding will intensify
the desired characters.
Foremost
among these desired characters
is concentrated ripening, the tendency
for all or nearly all the berries to be
ripe for one harvest.
Five to seven
generations of crosses between parents
selected for concentrated ri ening has resulted in numerous seedp i. ng selections
with 80 to 90% of the berries
ripe at one time.
Aborted primary
blossoms and sometimes aborted secondary
blossoms permit non-aborted
tertiary blossoms to fruit almost simultaneously.
Quarternary and quintary
blossoms may then also abort producing
a very concentrated, generally uniform
fruited clone.
Environment may
have considerable effect in aborting
blossoms that have a tendency to
abort, as is possibly the case for several
current Iowa selections.
Other desirable traits include easycap
tendency, brittle pedicel, protruding
seeds (versus sunken seeds),
tough skin, firm flesh, small leaves
(unless foliage is removed pre-harvest), long fruit stems, necked berries
(or at least not a sunken calyx), and
a large tufted calyx for cushion effect,
although tufted calyxes are often associated
with sunken calyxes and difficult
capping.
Further observations: Berry size is
generally not important for machine
harvesting, several concentrated ripening
selections have been small.
Size
can be incorporated later if we really
need it.
Crowded conditions of plants
in the first fruiting year tends to favor
concentrated ripening.
It is noteworthy
however, that even in the greenhouse
during February and March,
concentrated harvest selections utilized
for graduate student programs
maintained a strong tendency to concentrate
their production primarily by
aborted blossoms when crowding was
not a factor.
This study is continuing.
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