Spring Barley Production Guide - College of Agricultural and Life ...

1989 and 1990. These studies evaluated the interaction
between planting date and seeding rate for four spring
barley varieties (Triumph, Klages, Moravian III, and Morex)
in 1989 and two spring barley varieties (Moravian III and
Klages) in 1990. These varieties were planted at approximately
two-week intervals between mid-April and early
June and were seeded at 60, 80, 100, or 120 pounds per
acre.
Each one-week delay in planting after mid-April decreased
yields by about 300 to 400 pounds per acre. Most
of this decrease in yield resulted from a reduction in the
number of heads per square foot and the number of kernels
per head. Test weight and kernel plumpness were
not affected by planting date in 1989 but were both reduced
at the June 2 planting date in 1990. Klages was
particularly susceptible to reductions in kernel plumpness
associated with late planting.
Seeding Rate
Irrigated spring barley in southern Idaho should be
planted at rates of 100 to 120 pounds per acre on a pure
live seed (PLS) basis, depending on variety selection. Varieties
that tiller well can usually be seeded at 100 pounds
per acre; those that do not may benefit from higher seeding
rates.
Under dryland conditions, high seeding rates can reduce
barley yield if soil moisture is depleted before grain
filling is complete. Consequently, dryland barley in southern
Idaho should be seeded at 60 to 80 pounds per acre.
Actual seeding rates on a PLS basis are calculated by
dividing the desired seeding rate by the percentage of
pure, live seed in a seedlot as determined from standard
germination and purity tests:
Desired seeding rate (lb/acre) = Actual seeding
(% germination/100) x (% purity/100) rate (lb/acre)
For example, if the desired seeding rate is 100 pounds
per acre and the seedlot has a 93 percent germination
rate and 97 percent purity, then the actual seeding rate
would be
100 lb/acre = 111 lb/acre
(93/100) x (97/100)
Seeding Depth
Best germination and emergence of irrigated spring
barley occur at seeding depths of 1.0 to 1.5 inches when
there is adequate soil moisture. Double disk openers are
best for seeding spring barley into moisture at a uniform
depth under conventional conditions. Hoe-type openers
IDAHO SPRING BARLEY PRODUCTION GUIDE
16
place seed less exactly but can be used with less seedbed
preparation. Using press wheels or roller-packers after
seeding improves seed contact with soil moisture.
Row spacing
Commercial drills with a 6- to 8-inch row spacing do an
excellent job of distributing spring barley seed for irrigated
environments in southern Idaho. Studies conducted under
irrigated conditions in southern Idaho have shown that
varying the row spacing from 3.5 to 10.5 inches has no
affect on the yield of the major spring barley varieties.
Narrower row spacings permit quicker row closure by the
crop and may reduce weed competition.
Broadcast seeding
Barley is occasionally seeded using fertilizer spreaders
followed by some tillage, furrowing, or bed-shaping practice
that provides for some covering of the seed with soil.
Barley seed is sometimes broadcast with fertilizers. This
broadcast seeding is fast and relatively inexpensive. The
convenience and reduced cost is tempting to producers
trying to minimize the inputs into their barley production.
It is used as an emergency measure by some who otherwise
have difficulty with timely early plantings due to
weather or soil conditions.
Broadcast seeding is particularly risky for spring barley.
The seed to soil contact is invariably poorer than with conventional
seeding operations. The seed frequently ends
up at variable depths, depending on the practice used to
cover or mix the seed with soil. The loose soil around the
seed dries out more rapidly. With poorer moisture conditions,
germination can be delayed or reduced, or fewer
seedlings survive. Broadcast seeding rates are generally
increased 25 to 100 percent to compensate for the reduced
germination, delayed emergence, poorer seedling
survival, and reduced plant population. But higher seeding
rates still fail to give the most productive stands in
many cases.
If broadcast seeding is deemed necessary, the subsequent
tillage should provide adequate cover for the seed
and, if possible, the field should be irrigated lightly to insure
adequate moisture for timely germination. Spring soil
moisture conditions can be quite variable and precipitation
infrequent. Even with rain, windy conditions following
the rain can rapidly dry out loosely packed soils. Depending
on rainfall to provide the moisture necessary for
timely germination and stand establishment can be disastrous
if rainfall is not received or received in less than
sufficient amounts.