Agriculture Reference
In-Depth Information
Fig. 6.2.
Large tubers and yields like these typically require a large, broad ridge (hill) to protect against
tuber greening and quality loss. (Photo courtesy of M.J. Pavek.)
that limits tuber greening and protects the
tubers and roots against temperature and mois-
ture extremes throughout the season.
Planting depth should be adjusted for each
growing region, variety, and anticipated harvest
date. Seed pieces should be planted deep enough
to avoid soil moisture deficits, tuber greening,
and to accommodate the predicted yield. Pota-
toes should also be planted shallow enough to
enable rapid, uniform emergence, thereby redu-
cing disease and allowing for early growth.
Other important planting depth considerations
include cultivar physiology and growth charac-
teristics, post-planting tillage and weed control
needs, harvester capabilities, harvest date (early
versus late), and the requirements of the in-
tended market.
move the seed from a large bowl or the hopper
into the planter furrow. Pick planters may facili-
tate seed decay and disease spread by creating an
entry wound on each seed piece. In addition, the
delicate picks must be inspected routinely for
damage from foreign material. Other planter
types exist, but are less common in large-scale
production.
Planting seed pieces of different shapes and
sizes can prove difficult. A 2005 survey indi-
cated that an average of 6% (2700 plants ha
-1
)
of the intended plant population was missing
from Washington State (USA) potato fields due
to planter skips (Pavek and Thornton, 2005).
Moreover, the other 94% was non-uniformly
spaced. A related study determined these issues
collectively were costing growers US$200-
250
ha
-
1
(Pavek and Thornton, 2006). Pavek and
Thornton (2005) postulated that the combin-
ation of poor planter design and irregularly
shaped seed was largely to blame. In 1983, Entz
and LaCroix reported that whole seed tubers, of
uniform shape and size, planted more uniformly
than cut, irregularly shaped seed pieces; this
finding was confirmed in 2005 by Pavek and
Thornton. Other studies suggest planter per-
formance is compromised by insufficient man-
agement and maintenance, improper seed-bowl
levels, improper ground speed, and planter de-
sign (Hyde
et al
., 1979; Sieczka
et al
., 1986).
6.11 Planter Types and
Common Issues
Commercial producers typically rely on cup- or
pick-type planters. As the name infers, cup
planters use small cups to move seed tubers or
pieces from a planter hopper into a planter-
created furrow. There are various cup-type models,
and some incorporate a vacuum to aid in cup fill-
ing and seed dropping. Instead of a cup, the pick
planter uses a small nail-like pick to pierce and
