The heat units (HU) (growing days >10C) were
Table 1. Festuca cultivars tested for germination at
various temperatures.
calculated as
Cultivars
Scientific name
Common name
HU = (T Tb) Atg .
(4)
Jamestown, Festuca rubra var.
Chewings fescue (CF)
The experimental design was considered as a
Victory
commutata Gaud.
series of experiments repeated four times over
Cindy,
Festuca rubra L.
Creeping red fescue (CRF)
temperature with replications nested within
Dawson
temperature as described by Kempthorne (1952).
Spartan,
Festuca ovina var.
Hard fescue (HF)
Within each temperature treatment (germination
Reliant
duriuscula (L.) Koch.
chamber), the design was a randomized com-
Arctared,
Festuca rubra L.
Red fescue (RF)
plete block. Separate analyses of variance were
Jasper
structured for germination and average time to
Sheeps fescue (SF)
Azay
Festuca ovina L.
germination.
Clemfine,
Festuca arundinacea
Tall fescue (TF)
Tribute
Schreb.
RESULTS AND DISCUSSION
commercial source in New Jersey. Seeds (50) of
A pooled analysis of variance indicated that
each cultivar were selected at random and
cultivar and temperature treatments had a
placed in growth pouches. The growth pouches
significant effect on the mean germination and
were placed in the germination chamber for six
average time to germination of Festuca sp. (Table
2). The cultivar temperature interactions were
weeks at constant temperatures of 10, 15, 20, 25,
or 30C and 75% relative humidity. Germination
also significant (p < 0.001) for germination and
counts were recorded daily. Seed germination
was determined by radicle protrusion through
workers for forage legumes (Brar et al. 1991),
the seed coat, in accordance with the Association
sorghum (Brar and Stewart 1994), and warm-
of Official Seed Analysts (AOSA 1970) definition
season forage grasses (Hsu et al. 1985).
of seed germination.
The germination percentages at 28 days after
Table 2. Analysis of variance for labora-
imbibing were calculated from the total number
tory germination and average time to
of seeds germinated at each temperature divided
germination (Atg) of 11 Festuca culti-
by the total number of seeds used for each
vars.
cultivar. The weighted mean germination time
Source of
Mean squares
(Heydecker 1966, Brar and Stewart 1994) or aver-
variance
df
Germination
Atg
age time to germination (Atg in days) was calcu-
Cultivars (C)
10
10477*
88*
lated as
Temperature (T)
4
94*
610*
CT
n d
40
566*
8*
Atg = ∑
(1)
Error
165
39
0.7
N
* Significant at p = 0.001 probability level.
where n is the number of seedlings germinated
Germination percentage averaged across all
on day d, and N is the total number of seedlings
cultivars significantly (p < 0.05) increased as tem-
germinated.
perature increased, from 71% at 10C to 80% at
A linear regression model proposed by Angus
15C (Table 3). Germination percentage declined
et al. (1981) was used to estimate the threshold
above 15C and remained nearly constant as the
temperature for germination:
temperature increased to 30C. Cultivars were
grouped into three categories based on mean
Atg1 = b0 + b1 T
(2)
germination performance across temperature
treatments: rapid, with germination above 90%;
where T is temperature, and b0 and b1 are the
moderate, with germination between 80% and
regression constants. Threshold temperature (Tb)
90%; and slow, where germination was less than
was estimated as
80% (Brar and Stewart 1994). Among the culti-
vars tested across all temperatures, one was
b0
Tb =
.
(3)
rapid, six were moderate, and four were slow
b1
2
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