SPECIAL REPORT 97-19

The Effects of Temperature on

Germination of Eleven

Festuca Cultivars

Antonio J. Palazzo and Gurdarshan S. Brar August 1997
Abstract: Many studies have shown that water

potential at planting affects the germination rate and

final germination of Festuca cultivars. Limited information is available about the extent of variability in

temperature-dependence of germination among

different Festuca cultivars. Our objective was to study

germination at five temperatures for a wide range of

Festuca cultivars. Festuca seeds were screened for

germination during 28 days in polyethylene growth

pouches held at constant temperatures of 10, 15, 20,

25, or 30°C. The germination percentage significantly

(p < 0.05) increased as the temperature increased

from 10 to 15°C, when averaged across the cultivars,

and decreased thereafter. The cultivar “Clemfine” tall

fescue (Festuca arundinacea Schreb.) had the greatest germination percentage, and “Arctared” red fescue

(Festuca rubra L.) had the least when averaged

across the five temperatures. Conversely, the average

time to germination (Atg) was greatest at 10°C and

least at 30°C. Reaching a germination level of 80%

or more of the seeds required 14 days at 10°C, 9 d at

15°C, 8 d at 20°C, and 7 d at 25 or 30°C. Base

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temperatures required for germination of Festuca

species were 3.2°C for rapid germinators, 3.6 to 6°C

for medium germinators, and 4 to 6°C for poor germinators. Heat units (growing degree-days >10°C)

calculated for the rapid germinators were 129°C-d,

120 to 140°C-d for medium germinators, and 135 to

191°C-d for the poor germinators. Germination

decreased as heat units were increased. The Atg and

heat unit regressions explained 91% and 66% of the

variations in germination, respectively. The optimum

temperature for germination of Festuca cultivars was

15°C. Seeding time for some Festuca cultivars could

be varied based on expected seed zone temperatures

for particular locations. Results of this study should be

interpreted with caution, but they suggest that selection for rapid growth rate among materials of favored

phenological patterns may lead to improved establishment of faster species on poorly managed sandy

soils in cold climates. Rapidity and total germination

are the most obvious factors distinguishing Festuca

cultivars. This study demonstrates the variability in

cultivar germination in response to temperature.
Special Report 97-19

The Effects of Temperature on

Germination of Eleven

Festuca Cultivars

Antonio J. Palazzo and Gurdarshan S. Brar August 1997

Prepared for

OFFICE OF THE CHIEF OF ENGINEERS

Approved for public release; distribution is unlimited.

US Army Corps

of Engineers®

Cold Regions Research &

Engineering Laboratory
PREFACE

This report was prepared by Antonio J. Palazzo, Research Agronomist, and Gurdarshan S. Brar, Research Physical Scientist, Geochemical Sciences Division,

Research and Engineering Directorate, U.S. Army Cold Regions Research and Engineering Laboratory (CRREL), Hanover, New Hampshire.

Funding for this research was supported by project BT-25, work unit BT25-ECB09, entitled Genetic characterization of native plants in cold regions.

Technical review of this report was provided by Dr. Richard Hall, University of

Rhode Island; Dr. Ray Taylorson, U.S. Department of Agriculture; and Dr. Charles

Racine, CRREL. The authors also thank Timothy Cary for technical support.

The contents of this report are not to be used for advertising or promotional purposes. Citation of brand names does not constitute an official endorsement or

approval of the use of such commercial products.

ii
INTRODUCTION

Once established, hard fescues (Festuca sp.)

can survive for many years on military training

lands consisting of sandy soils (Palazzo 1994).

Major constraints of Festuca establishment are

lack of sufficient water in the seed zone, variation in seed zone temperature at planting, and

harsh environmental conditions. The period

between planting and seedling emergence comprises two distinct temperature-dependent

phases: seed germination and preemergence

seedling growth (Wheeler and Ellis 1991).

Selecting Festuca cultivars for rapid and uniform

germination under a wide range of temperatures

would seem to be important for early seedling

establishment. The cultivars that germinate

quickly might be capable of rapidly developing a

root system that would move ahead of the

drying soil front.

A broad classification of grasses based on

optimum temperature coincides with their separation into photosynthetic pathway types: coolseason grasses represent the C3 pathway, and

warm-season grasses use the C4 photosynthetic

pathway (Gould and Shaw 1983). Compared

with C3-type plants, C4 species are more resistant to drought (Doliner and Joliffe 1979); however, it is unclear if this analogy extends to the

germination and seedling stages. Total germination and germination rates of cool-season and

warm-season grasses were significantly influenced by the interaction of temperature and

water stresses (Qi and Redmann 1993). High and

low temperature extremes increased the sensitivity of germination rate to moisture stress and

decreased the germination percentage.

The importance of germination rate in the

The Effects of Temperature on Germination

of Eleven Festuca Cultivars

ANTONIO J. PALAZZO AND GURDARSHAN S. BRAR

establishment of annual grasses has been

reported in the literature (Derwyn et al. 1966,

Smith 1968). The germination rate, defined as the

reciprocal of the time taken for half the population to germinate, usually increases linearly with

temperature, at least within a well-defined range

(Hegarty 1973, Bierhuizen and Wagenvoort 1974,

Thompson and Fox 1976).

Selecting Festuca cultivars for rapid and uniform germination under a wide range of temperatures is important for early seedling establishment in the field (Brar and Stewart 1994).

Temperature affects germination of grass seeds,

with varying responses among species (McWilliam et al. 1970). Slow germination and low seedling vigor limit the establishment of perennial

warm-season forage grasses, and temperature is

a major environmental factor influencing both

processes (Hsu et al. 1985)

Little information is available about environmental influences on germination and the extent

of variability in germination at various temperatures for different Festuca cultivars. Therefore,

our objective was to study the effect of five temperatures on the germination percentage for a

wide range of Festuca cultivars.

MATERIALS AND METHODS

Festuca germination experiments were conducted in a growth chamber at the U.S. Army

Corps of Engineers Cold Regions Research and

Engineering Laboratory in Hanover, New

Hampshire. Eleven Festuca cultivars (Table 1)

were evaluated for germination under various

temperatures by a growth pouch technique (Brar

et al. 1991). Festuca seeds were obtained from a
commercial source in New Jersey. Seeds (50) of

each cultivar were selected at random and

placed in growth pouches. The growth pouches

were placed in the germination chamber for six

weeks at constant temperatures of 10, 15, 20, 25,

or 30°C and 75% relative humidity. Germination

counts were recorded daily. Seed germination

was determined by radicle protrusion through

the seed coat, in accordance with the Association

of Official Seed Analysts (AOSA 1970) definition

of seed germination.

The germination percentages at 28 days after

imbibing were calculated from the total number

of seeds germinated at each temperature divided

by the total number of seeds used for each

cultivar. The weighted mean germination time

(Heydecker 1966, Brar and Stewart 1994) or average time to germination (Atg in days) was calculated as

 

A n d

N tg =  ×



 

 ∑  (1)

where n is the number of seedlings germinated

on day d, and N is the total number of seedlings

germinated.

A linear regression model proposed by Angus

et al. (1981) was used to estimate the threshold

temperature for germination:

Atg

–1 = b0 + b1 T (2)

where T is temperature, and b0 and b1 are the

regression constants. Threshold temperature (Tb)

was estimated as

 

T b

b b = 0

1

. (3)

The heat units (HU) (growing days >10°C) were

calculated as

HU = (T– Tb) Atg . (4)

The experimental design was considered as a

series of experiments repeated four times over

temperature with replications nested within

temperature as described by Kempthorne (1952).

Within each temperature treatment (germination

chamber), the design was a randomized complete block. Separate analyses of variance were

structured for germination and average time to

germination.

RESULTS AND DISCUSSION

A pooled analysis of variance indicated that

cultivar and temperature treatments had a

significant effect on the mean germination and

average time to germination of Festuca sp. (Table

2). The cultivar × temperature interactions were

also significant (p < 0.001) for germination and

Atg. This study supports the findings of other

workers for forage legumes (Brar et al. 1991),

sorghum (Brar and Stewart 1994), and warmseason forage grasses (Hsu et al. 1985).

Germination percentage averaged across all

cultivars significantly (p < 0.05) increased as temperature increased, from 71% at 10°C to 80% at

15°C (Table 3). Germination percentage declined

above 15°C and remained nearly constant as the

temperature increased to 30°C. Cultivars were

grouped into three categories based on mean

germination performance across temperature

treatments: rapid, with germination above 90%;

moderate, with germination between 80% and

90%; and slow, where germination was less than

80% (Brar and Stewart 1994). Among the cultivars tested across all temperatures, one was

rapid, six were moderate, and four were slow

2

Table 1. Festuca cultivars tested for germination at

various temperatures.

Cultivars Scientific name Common name

Jamestown, Festuca rubra var. Chewings fescue (CF)

Victory commutata Gaud.

Cindy, Festuca rubra L. Creeping red fescue (CRF)

Dawson

Spartan, Festuca ovina var. Hard fescue (HF)

Reliant duriuscula (L.) Koch.

Arctared, Festuca rubra L. Red fescue (RF)

Jasper

Azay Festuca ovina L. Sheeps fescue (SF)

Clemfine, Festuca arundinacea Tall fescue (TF)

Tribute Schreb.

Table 2. Analysis of variance for laboratory germination and average time to

germination (Atg) of 11 Festuca cultivars.

Source of Mean squares

variance df Germination Atg

Cultivars (C) 10 10477* 88*

Temperature (T) 4 94* 610*

C × T 40 566* 8*

Error 165 39 0.7

* Significant at p = 0.001 probability level.
3

Germination (%)

Cultivar 10°C 15°C 20°C 25°C 30°C Mean

Jasper 89 93 87 93 86 89

Clemfine 94 94 88 89 96 93

Jamestown 94 92 83 88 77 86

Reliant 78 87 92 87 95 88

Azay 57 97 87 87 93 84

Spartan 79 88 77 83 72 80

Tribute 64 91 84 84 90 82

100

80

60

40

20

100

80

60

40

20

100

80

60

40

20

100

80

60

40

20

100

80

60

40

20

0

0 5 10 15 20 25 30 35 40 45

Days After Imbibing

Germination (%)

10°C

15°C

20°C

25°C

30°C

Arctared

Cindy

Clemfine

Table 3. Mean final germination percentage of Festuca cultivars as influenced by temperature at 28 days.

* Least-square differences at p <0.05 according to Student–Newman–Keuls test.

Germination (%)

Cultivar 10°C 15°C 20°C 25°C 30°C Mean

Victory 81 66 69 75 76 73

Cindy 92 92 55 43 27 60

Dawson 57 66 74 72 70 68

Arctared 0 15 14 17 14 12

LSD* (0.05) 11 7 11 11 8 4

Mean 71 80 73 74 72

LSD (0.05) = 3

Figure 1. Germination trends for Festuca cultivars as influenced

by temperature and time after imbibing.

germinators (Table 3). Clemfine TF had the greatest germination percentage, followed by Jasper

RF. The lowest germination percentage was

recorded for Arctared RF.

Cultivars that germinate over a relatively wide

range of temperatures may be easier to establish

in the field than those with a highly

specific temperature requirement. Clemfine TF was most vigorous in germination among all the cultivars evaluated

because it exhibited the highest germination percentage over a broad range

of temperatures. Brar and Palazzo

(1995a) reported that Clemfine TF had

more rapid root development, grew

faster, and transpired more water than

Reliant HF. Cultivars Cindy CRF and

Victory CF are temperature-specific and

performed well at lower temperatures.

The cultivars Reliant HF, Azay SF, and

Tribute TF were poor germinators at

10°C but performed better between 15°

and 30°C.

Germination time response curves for

Arctared RF, Cindy CRF, and Clemfine

TF at all the temperatures studied revealed the magnitude of interactions

between cultivars and indicated that

temperature strongly influenced germination (Fig. 1). At 10°C, Clemfine TF and

Cindy CRF had their greatest germination percentage within 11 to 13 days.

However, Arctared did not germinate at

10°C. At 15°C, again Clemfine and

Cindy reached >80% germination at 10

d, while at the same time Arctared had

9% germination. Similarly, Clemfine

exceeded 80% germination by 9 d at

20°C, 7 d at 25°C, and 6 d at 30°C. Conversely, Cindy and Arctared failed to

reach even 60% germination at higher

temperatures. In regions where lower temperatures exist at planting, rapidly germinating cultivars such as Clemfine TF, Jamestown CF, and

Jasper RF may be best (Table 3). In addition, an

early high germination rate may allow rapid

establishment on poorer sandy soils where the
water content in the upper soil surface is only

available for a short time. Brar and Palazzo

(1995b) emphasized that screening of turfgrass for

rapid root development is important for both

quicker establishment and long-term persistence

for disturbed soils and adverse climatic

conditions.

Average time to germination decreased as temperature increased from 10 to 15°C (Table 4). The

mean Atg was greatest at 10°C and lowest at 30°C.

Clemfine and Jasper were among the cultivars

with lowest Atg at each temperature. The poor

germinator (Arctared RF) had a greater Atg than

the other 10 cultivars. For 80% or more of the

seeds to germinate required an Atg of 14 d at 10°C,

9 d at 15°C, 8 d at 20°C, and 7 d at 25 or 30°C.

4

Table 4. Average time to germination (Atg in days)

of Festuca cultivars as influenced by temperature.

Atg

Cultivar 10°C 15°C 20°C 25°C 30°C Mean

Jasper 13.4 9.2 7.6 6.4 6.8 8.7

Clemfine 12.5 9.3 8.0 6.8 6.3 8.6

Jamestown 13.3 8.6 8.9 6.8 8.6 9.0

Reliant 13.5 8.6 8.5 6.5 6.8 8.8

Azay 14.8 10.0 7.9 7.4 7.3 9.5

Spartan 15.5 8.9 8.2 6.3 7.2 9.3

Tribute 14.1 9.8 8.0 6.9 6.6 9.1

Victory 14.6 9.9 8.9 8.5 7.2 9.8

Cindy 12.4 9.0 8.5 8.2 8.6 9.3

Dawson 14.4 10.8 8.5 8.6 7.5 9.9

Arctared 25.0 14.2 12.1 11.7 10.5 14.7

LSD* (0.05) 1.1 1.3 1.4 1.1 1.0 0.5

Mean 14.9 9.9 8.6 7.6 7.5

LSD (0.05) = 0.3

* Least-square differences at <0.05 according to StudentNewman-Keuls test.

100

80

60

40

20

0

8 9 10 11 12 13 14 15 16

Average Time to Germination (days)

Mean Germination (%)

b0 = 197.3

b1 = –12.7

r2 = 0.91

n = 11

100

80

60

40

20

0

120 140 160 180 200

Heat Units (C° days)

Mean Germination (%)

b0 = 200.5

b1 = –0.93

r2 = 0.66

n = 11

Figure 2. Relationship of mean germination and average time to germination.

Figure 3. Relationship of mean germination and heat units.
tion of cultivars based on anticipated seed zone

temperatures will provide rapid germination and

may lead to improved establishment on poorly

managed sandy soils in cold climates.

LITERATURE CITED

Angus, J.F., R.B. Cunningham, M.W. Moncur, and

D.H. Mackenzie (1981) Phasic development in

field crops. I. Thermal response in the seedling

phase. Field Crops Research, 3: 365–378.

AOSA (1970) Rules for testing seeds. In Proceedings of the Association of Official Seed Analysts, 60: 1–

116.

Bierhuizen, J.F., and W.A. Wagenvoort (1974)

Some aspects of seed germination in vegetables. 1.

The determination and application of heat sums

and minimum temperature for germination.

Scientific Horticulture, 2: 213–219.

Brar, G.S., and A.J. Palazzo (1995a) Tall and hard

fescue responses to periodic soil water deficits.

Journal of Agronomy and Crop Science, 175: 221–229.

Brar, G.S., and A.J. Palazzo (1995b) Shoot and root

development of tall and hard fescues in two different soils. Journal of Environmental Quality, 24:

777–781.

Brar, G.S., and B.A. Stewart (1994) Germination

under controlled temperature and field emergence of 13 sorghum cultivars. Crop Science, 34:

1336–1340.

Brar, G.S., J.F. Gomez, B.L. McMichael, A.G.

Matches, and H.M. Taylor (1991) Germination of

twenty forage legumes as influenced by temperature. Agronomy Journal, 83:173–175.

Derwyn, R., B. Whalley, and C.M. McKell (1966)

Seedling vigour and the early non-photosynthetic

stage of seedling growth in grasses. Crop Science,

6: 147–150.

Doliner, L.H., and P.A. Jolliffe (1979) Ecological

evidence concerning the adaptive significance of

the C4 dicarboxylic acid pathway of photosynthesis. Oecologia, 38: 23–34.

Garcia-Huidobro, J., J.L. Monteith, and G.R. Squire

(1982) Time, temperature and germination of

pearl millet. Journal of Experimental Botany, 33:

288–296.

Gould, F.W., and R.B. Shaw (1983) Grass Systematics. Second edition, p. 397. College Station: Texas

A&M University Press.

Hegarty, T.W. (1973) Temperature coefficient

(Q10), seed germination and other biological processes. Nature (London), 243: 305–306.

Heydecker, W. (1966) Clarity in recording germination data. Nature, (London), 210: 753–754.

5

Base temperatures required for germination of

Festuca species were 3.2°C for rapid germinators,

3.6 to 6°C for medium germinators, and 4 to 6°C

for poor germinators. Heat units (HU) (growing

degree-days >10°C) calculated for the rapid germinator were 129°C-d, 120 to 140°C-d for medium

germinators, and 135 to 191°C-d for the poor

germinators. Radford and Henzell (1990) reported that differences among sorghum genotypes for

germination were due to differences in base temperature. Furthermore, they speculated that any

genotype with a high base temperature might

have insufficient time to complete elongation of

radiate protrusion through the seed coat and subsequently fail to germinate.

The mean germination of Festuca cultivars was

significantly (p < 0.05) regressed with mean Atg

(Fig. 2) and heat units (Fig. 3). Germination

decreased as Atg and HU increased. The Atg and

HU regressions explained 91% and 66% of the

variation in germination, respectively.

Cultivars that germinated rapidly had lower

HU and Atg values, so they have the chance to

establish in the field earlier than medium and

slow germinators (Brar and Stewart 1994).

Rapid and total germination are the most

obvious factors distinguishing the cultivars used

in this study. The two TFs (Clemfine and Tribute)

as a group had a greater total and rate of germination than the other five species. Palazzo and Brar

(1997) screened Festuca cultivars for rapid root

development and reported that Clemfine TF had

the deepest root system and greatest cumulative

root elongation rates among the 12 cultivars used

in the test. The rate of germination increased

linearly with temperature from a base temperature to a sharply defined optimum temperature,

beyond which the rate decreased linearly with

temperature, reaching zero at the maximum temperature (Garcia-Huidobro et al. 1982).

In summary, we examined the effects of temperature on germination, average time to germination, threshold temperature, and heat units of

Festuca cultivars to assess the genetic basis for

their variability and the implications for selection

and turfgrass establishment. The results of this

study suggest that the optimum seed zone temperature for germination of Festuca cultivars is

15°C. Germination decreased as average time to

germination increased. The seeding time for some

Festuca cultivars could be varied based on expected seed zone temperatures for particular

locations. Results of this study should be interpreted with caution, but they suggest that selec-
Hsu, F.H., C.J. Nelson, and A.G. Matches (1985)

Temperature effects on germination of perennial

warm-season forage grasses. Crop Science, 25:

215–220.

Kempthorne, O. (1952) The design and analysis of

experiments. New York: John Wiley and Sons.

McWilliam, J.R., J.R. Clements, and P.M. Dowling

(1970) Some factors influencing the germination

and early seedling development of pasture

plants. Australian Journal of Agricultural Research,

21: 1932.

Palazzo, A.J. (1994) Establishment and persistence of cool- and warm-season grasses on sandy

soils. USA Cold Regions Research and Engineering Laboratory, Special Report 94-31.

Palazzo, A.J., and G.S. Brar (1997) Screening of 12

Festuca cultivars for rapid root development.

Journal of Turfgrass Management, 2: 15–25.

Qi, M.Q., and R.E. Redmann (1993) Seed germination and seedling survival of C3 and C4 grasses

6

under water stress. Journal of Arid Environments,

24: 277-285.

Radford, B.J., and R.G. Henzell (1990) Temperature affects the mesocotyle and coleoptile length

of grain sorghum genotypes. Australian Journal of

Agricultural Research, 41: 79–87.

Smith, D.F. (1968) The growth of barley grass

(Hordeum leporinunum) in an annual pasture. I.

Germination and establishment in comparison

with other annual pasture species. Australian

Journal of Experimental Agriculture and Animal

Husbandry, 8: 478–483.

Thompson, P.A., and D.J.C. Fox (1976) The germination responses of vegetable seeds in relation

to their history of cultivation by man. Scientific

Horticulture, 4: 1–14.

Wheeler, T.R., and R.H. Ellis (1991) Seed quality,

cotyledon elongation at suboptimal temperatures, and the yield of onion. Seed Science Research, 1: 57–67.
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August 1997

The Effects of Temperature on Germination of

Eleven Festuca Cultivars

Antonio J. Palazzo and Gurdarshan S. Brar

U.S. Army Cold Regions Research and Engineering Laboratory

72 Lyme Road Special Report 97-19

Hanover, New Hampshire 03755-1290

Office of the Chief of Engineers

Washington, D.C. 20314-1000

 11

Festuca cultivars Germination Temperature

UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED UL

Many studies have shown that water potential at planting affects the germination rate and final germination of

Festuca cultivars. Limited information is available about the extent of variability in temperature-dependence of

germination among different Festuca cultivars. Our objective was to study germination at five temperatures for a

wide range of Festuca cultivars. Festuca seeds were screened for germination during 28 days in polyethylene

growth pouches held at constant temperatures of 10, 15, 20, 25, or 30°C. The germination percentage significantly

(p < 0.05) increased as the temperature increased from 10 to 15°C, when averaged across the cultivars, and

decreased thereafter. The cultivar “Clemfine” tall fescue (Festuca arundinacea Schreb.) had the greatest germination percentage, and “Arctared” red fescue (Festuca rubra L.) had the least when averaged across the five

temperatures. Conversely, the average time to germination (Atg) was greatest at 10°C and least at 30°C. Reaching

a germination level of 80% or more of the seeds required 14 days at 10°C, 9 d at 15°C, 8 d at 20°C, and 7 d at 25 or

30°C. Base temperatures required for germination of Festuca species were 3.2°C for rapid germinators, 3.6 to 6°C

for medium germinators, and 4 to 6°C for poor germinators. Heat units (growing degree-days >10°C) calculated

for the rapid germinators were 129°C-d, 120 to 140°C-d for medium germinators, and 135 to 191°C-d for the poor

germinators. Germination decreased as heat units were increased. The Atg and heat unit regressions explained
91% and 66% of the variations in germination, respectively. The optimum temperature for

germination of Festuca cultivars was 15°C. Seeding time for some Festuca cultivars could be

varied based on expected seed zone temperatures for particular locations. Results of this study

should be interpreted with caution, but they suggest that selection for rapid growth rate

among materials of favored phenological patterns may lead to improved establishment of

faster species on poorly managed sandy soils in cold climates. Rapidity and total germination

are the most obvious factors distinguishing Festuca cultivars. This study demonstrates the

variability in cultivar germination in response to temperature.

13. ABSTRACT (cont’d)