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THES‘S

IllilliilllllllllIllllllllllllllllllll'lll L

31293 01710 2942

This is to certify that the

thesis entitled

Field and Laboratory Performance of Winter Wheat
Seed Affected by Pre-Harvest Sprouting and Storage

presented by

Marcelo Que ij 0

has been accepted towards fulfillment
of the requirements for

MastergLSgienggdegree in Crop and Soil Sciences

 

0:4. 0. afloat

Major professor

Date January 23, 1998

 

0-7639 MS U is an Affirmative Action/Equal Opportunity Institution

 

 

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University

 

 

 

PLACE iN RETURN BOX
to remove this checkout from your record.
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DATE DUE DATE DUE DATE DUE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1M C'JCIWDpGS-p.“

 

FIELD AND LABORATORY PERFORMANCE OF WINTER WHEAT SEED
AFFECTED BY PRE-HARVEST SPROUTING AND STORAGE

By

Marcelo Queijo

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Crop and Soil Sciences

1998

 

ABSTRACT

FIELD AND LABORATORY PERFORMANCE OF WINTER WHEAT SEED
AFFECTED BY PRE-HARVEST SPROUTING AND STORAGE
By

Marcelo Queijo

Field and laboratory experiments were conducted on two winter wheat
varieties representing different imbibition periods and storage levels to measure
the effects of nonvisible incipient sprouting (NVIS) on germination, storability and
field performance. Warm germination, tetrazolium and accelerated aging test
performance were evaluated in the laboratory experiments. Seed lots with higher
NVIS resulted in the lowest germination, especially under longer periods of
storage. A strong interaction between imbibition period and storage occurred in
both laboratory and field tests. Germination of visibly sprouted seed decreased
more rapidly than for nonvisibly sprouted seed over time. No differences in field
emergence, spring quantitative regrowth index, and yield occurred among
varieties. Highly significant differences in field performance occurred between
NVIS seed and that with visible sprouting damage. Generally, damage from
NVIS affected the quality of seed as well as its field performance if seed lots

were stored more than 2 months.

V

TO THE MEMORY OF

Don José A. Queijo to whom I owe

 

my love and dedication to agriculture

 

ACKNOLEDGEMENTS

i will always be thankful to Dr. Lawrence 0. Copeland, my major professor,
for his continuous support, patience, dedication and advice. His encouragement
and guidance were very important in the completion of this work.

I am also grateful to the members of my committee, Dr. James Kells and Dr.
Perry Ng, for their suggestions and cooperation during this work.

A sincere thanks goes to Mr. Hongyu Liu, for his assistance, suggestions and
help along these two years. Also, I am thankful to the members of the Wheat
crew for their help and collaboration, especially to Mr. Larry Fitzpatrick.

i would like to express my appreciation to all the members of Michigan Crop
Improvement Association for helping me so much during all this time, especially
Mrs. Ann Tucker whose support and assistance were very important to make this
program successful.

To my wife, Gabriela, and my parents and sister, thank you very much for

your love, patience and support.

 

TABLE OF CONTENTS

Page
LIST OF TABLES vii
LIST OF FIGURES ix
LIST OF APPENDIX TABLES x
INTRODUCTION 1
LITERATURE REVIEW
Breeding for Sprouting Resistance 3
Seed Dormancy 4
Seed Coat 5
Position 6
Ripeness 6
Enzymes 7
Economic Impact 9
Nonvisible Sprouting Damage 11
Tetrazolium Test 12
Summary 14
OBJECTIVES OF STUDY 15
MATERIALS AND METHODS
Laboratory Experiments 15

Field Experiment 20

RESULTS AND DISCUSSION
Laboratory experiments
Tetrazolium viability
Nonvisible incipient sprouting
Standard Warm Germination
Accelerated Aging
Field experiments
Field emergence
Quantitative regrowth index potential

Grain Yield

DISCUSSION AND RECOMMENDATIONS
Recommendations
APPENDIX

LITERATURE CITED

vi

22
3O
38

43

46

54

59

63

66

67

87

 

Table

Table 1.

Table 2.
Table 3.

Table 4.

Table 5.

Table 6.

Table 7.

Table 8.

Table 9.

Table 10.

Table 1 1.

Table 12.

Table 13.

LIST OF TABLES

Description of tables

Description of sprouting levels obtained after periods of
imbibition in all experiments during 1995 and 1997

Description of classification criteria used for the tetrazolium test
Tetrazolium test results (TZ viability) and nonvisible incipient
sprouting (NVIS) of Lowell and Mendon, 1995

Percent tetrazolium (TZ) viability of Lowell and Mendon in
1996

Least square means for TZ viability of Lowell and Mendon in
1996

Least square means for the interaction between imbibition
period and storage on T2 viability of Lowell and Mendon in
1996

Percent tetrazolium (TZ) viability showing the effects of
imbibition period (IP) and storage on Lowell and Mendon in
1997

Percent nonvisible incipient sprouting (NVIS) for different
imbibition periods and storage of Lowell and Mendon in 1996
Percent nonvisible incipient sprouting (NVIS) for different
imbibition periods and storage of Lowell and Mendon in 1997
Percent germination following different imbibition period and
storage of Lowell and Mendon in 1996

Percent germination of Lowell and Mendon after different
periods of imbibition and storage in 1997

Percent accelerated aging germination for different imbibition
period (IP) and storage of Lowell and Mendon in 1997

Field emergence 21 days after planting for Lowell in 1995

vii

Page

16

19
22

24

27

27

32

37

39

41

43

47

Table 14.

Table 15.

Table 16.

Table 17.

Table 18.

Table 19.

Table 20.

Table 21.

Table 22.

Table 23.

Field emergence 21 days after planting following imbibition
period and storage of Lowell and Mendon in 1996 at East
Lansing and Clarksville, Ml

Field emergence 21 days after planting following imbibition
period and storage of Lowell and Mendon in 1996

Field emergence following imbibition periods (IP) of Lowell
and Mendon in 1996

Least square means for the interaction between imbibition
period and storage for field emergence of Lowell and
Mendon in 1996

Quantitative index of regrowth potential in the spring of 1997
following imbibition period and storage of Lowell and Mendon
at East Lansing and Clarksville, Ml

Quantitative index of regrowth potential in the spring of 1997
following imbibition period and storage of Lowell and Mendon
Least square means for the interaction between storage and
variety for the quantitative index of regrowth potential of
Lowell and Mendon in the spring of 1997

Least square means for the interaction between imbibition
period and storage for the quantitative index of regrowth
potential of Lowell and Mendon in the spring of 1997

Yield (kg/ha) of seed lots following imbibition period and
storage of Lowell and Mendon in 1997. Average of two
locafions

Least square means for the interaction between imbibition
period (IP) and storage on yield (kg/ha) in 1997

viii

49

50

51

53

55

56

56

58

60

60

 

Figure

Figure 1.
Figure 2.

Figure 3.

Figure 4.

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

LIST OF FIGURES

Description of Figures

Pictorial representation of tetrazolium test evaluation

The effect of imbibition period and storage on T2 viability of
Lowell and Mendon in 1996 and 1997

The effect of imbibition period and storage on nonvisible
incipient sprouting (NVIS) of Lowell and Mendon in 1996
and 1997

Effect of seed storage on decline of nonvisible incipient
sprouting (NVIS)

The effects of imbibition period and storage on the
germination of Lowell and Mendon in 1996 and 1997

The effect of imbibition and storage period on accelerated
aging germination of Lowell and Mendon in 1997

The effect of nonvisible incipient sprouting on field
emergence of Lowell in 1995

The effects of imbibition period and storage on the field
emergence of Lowell and Mendon in 1996

Index of regrowth potential following imbibition and storage
periods of Lowell and Mendon in 1997

The effects of imbibition period and storage on the grain

yield of Lowell and Mendon in 1997

Page

18
25

33

34

42

45

47

52

57

62

Table

Table A1 .

Table A2.

Table A3.

Table A4.

Table A5.

Table A6.

Table A7.

Table A8.

Table A9.

Table A10.

LIST OF APPENDIX TABLES

Description of tables

Analysis of variance for the effect of imbibition period (IP)
on T2 viability of Lowell and Mendon, 1995

Slicing procedure for the interaction between imbibition
period (IP) and variety for T2 viability of Lowell and Mendon
in 1995

Analysis of variance for the effect of imbibition period (IP)
and storage on TZ viability of Lowell and Mendon in 1996
Slicing procedure for the interaction between imbibition
period (IP) and variety on T2 viability in 1996

Slicing procedure for the interaction between imbibition
period and levels of storage on T2 viability in 1996

Analysis of variance for the effect of imbibition period (IP)
and storage on the TZ viability of Lowell and Mendon in
1997

Slicing procedure for the 3-way interaction among variety,
imbibition period (IP) and storage on TZ viability of Lowell
and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period and storage on nonvisible incipient
sprouting (NVIS) of Lowell and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period (IP) and storage on nonvisible incipient
sprouting (NVIS) in 1997

Analysis of variance for the effect of imbibition period (IP)
on nonvisible incipient sprouting (NVIS) of Lowell and
Mendon in 1995

Page

67

67

68

68

69

69

7O

70

71

71

 

Table A11.

Table A12.

Table A13.

Table A14.

Table A15.

Table A16.

Table A17.

Table A18.

Table A19.

Table A20.

Table A21.

Slicing procedure for the interaction between imbibition
period (IP) and variety on nonvisible incipient sprouting
(NVIS) of Lowell and Mendon in 1995

Analysis of variance for the effect of imbibition period and
storage on nonvisible incipient sprouting (NVIS) of Lowell
and Mendon in 1996

Slicing procedure for the interaction among variety,
imbibition period (IP) and storage on NVIS of Lowell and
Mendon in 1996

Slicing procedure for the interaction among variety,
imbibition period (IP) and storage on NVIS of Lowell and
Mendon in 1996

Slicing procedure for the interaction among variety,
imbibition period (IP) and storage on NVIS in 1996

Analysis of variance for the effect of imbibition period and
storage on nonvisible incipient sprouting (NVIS) of Lowell
and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period and storage on nonvisible incipient
sprouting (NVIS) of Lowell and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period (IP) and storage on nonvisible incipient
sprouting (NVIS) of Lowell and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period (IP) and storage on nonvisible incipient
sprouting (NVIS) of Lowell and Mendon in 1997

Analysis of variance for the effect of imbibition period and
storage on germination of Lowell and Mendon in 1996
Slicing procedure for the interaction among variety,

imbibition period and storage on germination of Lowell and

xi

72

72

73

73

74

74

75

75

76

76

77

 

Table A22.

Table A23.

Table A24.

Table A25.

Table A26.

Table A27.

Table A28.

Table A29.

Table A30.

Table A31.

Mendon in 1996

Slicing procedure for the interaction among variety,
imbibition period and storage on germination of Lowell and
Mendon in 1996

Least square means for the interaction among variety,
imbibition period and levels of storage on germination of
Lowell and Mendon in 1996

Analysis of variance for the effect of imbibition period (IP)
and storage on the germination of Lowell and Mendon in
1997

Slicing procedure for the interaction between variety and
imbibition period (lP) on germination of Lowell and Mendon
in 1997

Slicing procedure for the interaction between imbibition
period (IP) and storage on germination of Lowell and
Mendon in 1997

Analysis of variance for the effects of imbibition period (lP)
and storage on accelerated aging germination of Lowell
and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period (IP) and storage on accelerated aging
germination of Lowell and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period (IP) and storage on accelerated aging
germination of Lowell and Mendon in 1997

Slicing procedure for the 3-way interaction among variety,
imbibition period (IP) and storage on accelerated aging
germination of Lowell and Mendon in 1997

Analysis of regression for the effect of imbibition period (IP)

on field emergence for Lowell in 1995

xii

77

78

78

79

79

80

8O

81

81

82

I1

‘3-
I -

Table A32.

Table A33.

Table A34.

Table A35.

Table A36.

Table A37.

Table A38.

Table A39.

Table A40.

Field emergence 21 days after planting following imbibition
period and storage of Lowell and Mendon in 1996 at East
Lansing and Clarksville, Ml

Analysis of variance for the effect of imbibition period and
storage on field emergence of Lowell and Mendon in 1996
Slicing procedure for the interaction among imbibition
period and variety on germination across two locations for
Lowell and Mendon in 1996

Slicing procedure for the interaction between imbibition
period and storage on field emergence across two locations
for Lowell and Mendon in 1996

Analysis of variance for the effect of imbibition period and
storage on the field performance measured by a
quantitative index of regrowth potential of Lowell and
Mendon in 1996

Slicing procedure for the interaction between storage and
variety for quantitative index of regrowth potential across
two locations of Lowell and Mendon in 1996

Slicing procedure for the interaction between imbibition
period and storage for quantitative index of regrowth
potential across two locations of Lowell and Mendon in
1996

Analysis of variance for the effect of variety, imbibition
period and storage on yield (kg/ha) in 1997

Slicing procedure for the interaction between imbibition
period (IP) and storage on yield (kg/ha) of Lowell and
Mendon in 1997

xiii

82

83

83

84

84

85

85

86

86

IF "1"

INTRODUCTION

Preharvest sprouting in cereals is the precocious germination of the grain
while still in the ear in the field, usually in response to unfavorable weather
conditions (e.g., rain and high relative humidity) (Olered, 1967). This
phenomenon is a perennial problem in many parts of the world where there is a
high probability of rain during the harvest period (MacKey, 1976). Changes in
the chemical constituents of the wheat kernel which accompany germination and
which have deleterious effects on the subsequent commercial utilization of the
wheat are collectively known as preharvest sprouting.

It is clear that the most important aspect of preharvest sprouting is the
gerrninability of the grain at particular stages of maturity under different
environmental conditions (Mares, 1985). Susceptibility to preharvest sprouting in
wheat is dependent on genotype (Belderok, 1968; Bhatt et al., 1981; Bingham
and Whitmore, 1966; McCrate et al., 1981) and environmental conditions such as
moisture and temperature (Lalluka, 1976; Nielsen et al., 1984; Olson and
Mattson, 1976).

In some areas sprout damage in wheat occurs in climates with persistent
rain and cool temperatures before harvesting. In other areas, periods of rain
accompanied by high temperatures and high humidity before harvest increase
sprouting in wheat. High temperatures during the soft dough stage of grain
development have been reported to shorten the period of dormancy after

physiological maturity (Nielsen, 1980). Nielsen et al. (1984) also reported
1

 

preharvest sprouting to be more severe when large diurnal temperature
fluctuations and high precipitation occurred during and after physiological
maturity of the grain. Karkoven et al. (1991) noted that an average relative
humidity of over 80 percent and a maximum daily temperature of below 13°C
during grain filling decrease falling number levels to below 120 seconds (the
lower limit for commercially acceptable starch quality). On the other hand, if the
average relative humidity falls below 70 percent and the average maximum
temperature exceeds 16°C, falling number readings often go over 230 seconds.
It should be noted that wheat flour with falling number values below 120 seconds
are unacceptable for milling and can only be used for animal feed.

Following moisture imbibition, the germination sequence of the wheat
grain is sprouting, endospenn degradation, and alpha-amylase response.
Gordon et al. (1977) noted that other enzymes (other than alpha-amylase)
associated with germination also appear to contribute substantially to endospenn
degradation.

Sprouting in wheat occurs first by the penetration of the pericarp of the
kernel by the radicle, or primary root. During sprouting, the seeds enzyme
systems are mobilized and translocated to the interior of the endosperm where
they catalyze the breakdown of starches into soluble sugars that can be
translocated to growth areas of the embryo. The reduction of starch content and
increase in sugars has serious consequences on the use of sprouted wheat for

milling (Copeland et al., 1980).

Breeding for Sprouting Resistance

When wheat resists germination in intact spikes when subjected to
favorable conditions, it is said to be sprouting tolerant. Selection against
sprouting damage in wheat is usually based on lack of embryo growth or low
activity of alpha-amylase at some time after ripeness (Gordon et al., 1977).

Attempts to associate specific grain characteristics with resistance to
preharvest sprouting have been moderately successful. Seed coat
characteristics other than pigmentation have been reported to be associated with
decreased germinability of wheat seed (Nielsen, 1980). Chang (1943) concluded
that differences in sprouting resistance are in most cases due to differences in
length of dormancy and in some cases may be due to rapidity of germination.
Gordon et al. (1979) have shown that maturity also may contribute to sprouting
susceptibility.

The presence of awns hastens water loss from wheat ears during drying
and could enhance uptake during wetting (Pool and Patterson, 1958). King and
Chadim (1983) stated that a wheat variety bred for reduced preharvest sprouting
should be awnless.

It is generally accepted that the long-term solution to the preharvest
sprouting problem in wheat lies in the development of cultivars which are able to
tolerate or resist the damaging effects of rain during the period between ripeness
or maturity and the completion of harvest. For sprouting resistance, it is not
sufficient for the grain to be unable to germinate at morphological ripeness;

3

Belderok (1968) claimed that the crop must be able to stand in the field one or
two weeks longer without starting to sprout under prolonged rainy conditions.

D. J. Mares (1992) found considerable evidence to suggest that at least
part of the control of germination and presprouting resides in the embryo and is

mediated by abscisic acid (ABA) and/or other endogenous inhibitors.

Seed_Dorma_mcy

Seed dormancy is the failure of the seed to germinate when subjected to
favorable conditions. Dormancy is very important for the survival of many plant
species, however, it is considered to be a negative characteristic of a seed lot
being tested for germination. The positive effects of seed dormancy, however,
are more important than the negative ones for both cereal production and the
cereal industry. inhibition of the enzyme systems that are active during
germination is of fundamental importance for conserving cereal crop quality
under unfavorable harvest conditions (Ringlund, 1992).

Preharvest sprouting is closely related to the release of the seed from
dormancy. Dormancy normally disappears with storage, and this process is
temperature dependent (Belderok, 1961). Although seed dormancy is
recognized to be under genetic control, this control is also influenced by
environmental conditions during seed formation (Takahashi, 1979). Takahashi
(1967) showed that induction of dormancy was strictly affected by high
temperature and high moisture during the vegetative stage.

4

._.4 - Ji- .

The association between red seed coat color and dormancy is well
established, but it has only been recently that white seeded genotypes with
significant levels of dormancy have been identified (Bhatt and Derera, 1980; De
Pauw and McCaig, 1983 and 1990; Mares, 1987; Morris and Paulsen, 1987).
But as of today it has not been possible to transfer, in its entirety, the dormancy

associated with some red wheats into a white cultivar.

Seed Coat

Observations on the germination of wheat in the ear have shown that
varieties with white caryopses are more likely to sprout before harvest than those
with red caryopses (Wellington, 1953). Wellington (1956) proposed that the.
dormant, red grained wheat have a more restrictive seed coat than the white
seeded, nondormant wheat. He found that initial (24 hr) water absorption by the
embryo was similar for both dormant and nondormant grain. However, further
water uptake by the embryo was delayed in the dormant variety unless the
embryo was uncovered or the distal half removed.

Paulsen et al. (1984), in their research on agronomic and quality attributes
of sibling white and red winter wheat lines, cited several advantages for white
over red wheat regarding flour extraction, flour protein concentration, and other
desirable milling qualities; but, they also mentioned the greater susceptibility to

preharvest sprouting as the major disadvantage of white wheat over red wheat.

 

Collectively, the red seeded cultivars have higher initial seed dormancy,
lower tendency to sprout, greater capacity to maintain test weight, less visible
sprout damage to the grain, and higher seed viability under sprouting conditions

than similar cultivars with white seed (McEwan, 1975).

Position

The position in the ear can also affect the time when a particular wheat
seed is first able to germinate. Wellington (1953) noted that the first seeds to
germinate were those at the top of the ear which had started to change color.
Hardesty et al. (1956) found that sprouting starts in the top of the ear, follows

soon after at the base, and finally proceeds to the center.

Ripeness

In both red and white wheat varieties it appears that seeds are unable to
germinate as long as the pericarp remains green, but as soon as the covering
layers change color, a high proportion of the white seeds in the middle and top
spikelets become able to germinate. At the same time, very few of the seeds in
similar spikelets of red varieties are able to germinate, nor many in the lowest

spikelets in the ears of both white and red varieties (Wellington, 1953).

 

Wellington (1956) reported that no seeds are able to germinate while still
green, but with the disappearance of the chlorophyll and the rupture of the layer

containing chloroplasts during ripening, germination was able to occur.

Enzymes

Preharvest sprouting causes physiological and biochemical changes in the
grains which render them unsuitable for many end-uses. Enzyme activity is
known to increase greatly during cereal seed germination. The increased activity
of the amylases, particularly alpha-amylase, adversely affects grain quality of
wheat. Studies have shown that high levels of alpha-amylase in wheat flour
result in a sticky crumb, poor bread texture, and discolored crust (Morris and
Paulsen, 1985; Mares, 1985; Greenaway, 1969; Buchanan and Nicholas, 1979;
Lorenz, Roewe-Smith, Kulp, and Bates, 1984; Nielsen, 1980). Excess levels of
natural alpha-amylase activity produce a highly colored loaf with a sticky crumb
resulting from the production of potentially sticky substances with high molecular
weight dextrines and sugars during baking (Buchanan and Nicholas, 1979).
However, a small amount of alpha-amylase activity in flour has been shown to
enhance bread quality (Nielsen, 1980).

Olered (1964) showed that there are 2 types of alpha-amylases, one
mainly found in the pericarp of premature seeds, and another in germinating

seeds. Later it was shown that there were many isozymes for both types, both of

which are coded by 2 different genes, and dormancy is related to the gibberellic
acid insensitivity found in semi-dwarf wheats (Gale, 1983).

When cereals germinate, the amylases in the grain increase rapidly and
hydrolyze the starch in the endosperrn into sugars needed for seedling growth.
The consequences for the milling industry are that flour and meal from sprouted
wheat or rye contain increased amounts of alpha-amylase which adversely affect
baking quality; the ensuing breakdown of a proportion of the starch during baking
leads to sticky crumb texture and undesirable crust color of the bread. The most
important factor to the flour miller is the performance of the flour during baking,
hence the preference of the miller for alpha-amylase determination rather than
visual determinations of sprouting (Belderok, 1968). Thus, measurement of the
falling number has proved very suitable for this purpose. Mathewson and
Pomeranz (1977) considered alpha-amylase activity an appropriate estimate of
sprout damage as the enzyme activity reflected actual end-use properties of the
grain. Also, Hagemann and Ciha (1984) noted that germination tests are better in
predicting sprouting susceptibility whereas enzymatic tests are better in
quantifying actual end-use damage. The tetrazolium test was used in these
studies to measure the effect of nonvisible incipient sprouting on seed quality,

storability and performance.

Economic impact

Preharvest sprouting may seriously reduce the agronomic and milling and
baking quality of wheat grain, as well as its use as a thickening agent in cream
soups and gravy mixes.

As early as the 1930's, Harrington (1932) noted that sprouted grain has
distinctly less value for seed purposes or for milling than undamaged grain.

Visible sprouting occurs when the root-shoot axis breaks through the
pericarp cover. Such kernels are considered damaged by grain inspectors, often
resulting in substantial grower discounts.

Belderok (1961) stated that in northwest Europe, weather conditions result
in the occurrence of sprouting once in every three years. In Michigan, the
probability of serious sprouting damage due to unfavorable weather conditions is
about once in every four years, although some sprouting occurs almost every
year. It is clear that this phenomenon presents a serious problem to agriculture.
The incidence of sprout damage varies with the incidence of untimely rain at
harvest. Most of the world's major wheat producing regions are affected by
sprout damage to some degree.

Stoy (1983) noted the great economic losses that occur because of
sprouting damage to wheat in various regions of the world, and Weilenmann et
al. (1976) cited the substantial economic losses from decreased grain quality
caused by sprouting. Belderok (1968) estimated that a 10 percent yield
reduction due to preharvest sprouting would seem by no means exceptional.

9

Bhatt et al (1981) also noted that grain quality is adversely affected by preharvest
sprouting. In 1980, Copeland, Freed and Helsel estimated that as much as 50 to
60 percent of the acreage of soft white wheat in Michigan was affected by severe
sprouting in any given year. They noted the serious consequences of sprouted
wheat to the milling industry as well as its use for seed. Sprouting affects the
quality desired by end-users of wheat products because the enzymes that
determine crumb structure and the shape of baked products are affected. Wahl
and O'Rourke (1992) stated that the market value of sprouted wheat is reduced
because of its lower value to end-users, which results in economic losses to
farmers.

Regarding wheat seed quality, Copeland et al. (1980) noted that any
degree of sprouting will lower the seed quality to some extent, but may not
destroy its germination potential if sprouting is not too severe and if the moisture
content is brought down to safe levels (about 13.5 - 14.0 percent). Elias (1987)
showed that although seed with minimum presprouting can retain its capacity for
a period of time, presprouted wheat seed will lose germination capacity more
rapidly than non-sprouted seed. The time required for the loss of germination
depends on the extent of the presprouting and the storage conditions.

It's not easy to obtain reliable figures of the total damage that may be
caused during one year to the world's grain crops. However, there are many
examples from various regions where 30 to 50 percent or even more of the
grains harvested may be so severely damaged that they are unsuited for human

consumption.

10

Nonvisible Sprouting Damage

A rise in amylase activity in grain may cause the starch to begin breaking
down into sugars before sprouting in the ear can be observed visually (Sumeola,
1965; LaCroix et al, 1976). Gold and Duffus (1992) denoted the production of
alpha-amylase by pre-ripe grains in the absence of visible sprouting as pre-
maturity alpha-amylase (PMAA). Gale and Lenton reported the first widespread
damage due to PMAA in 1987. In 1992, Mares and Mrva reported that several
wheat cultivars produced (during the later stages of grain ripening) significant
levels of alpha-amylase that reduce falling number levels below commercially
acceptable levels.

Nonvisible sprouting injury has been detected by seed analysts at
Michigan Crop Improvement Association with the tetrazolium test. They have
observed critical unstained portions of the embryo (which are an indicator of
dead tissue) in wheat seeds not showing visible sprouting damage. The term
“weak seed” has been applied to this phenomenon denoting that those
caryopses have undergone the very first stages of sprouting. We suggest that
this phenomenon should be denoted as nonvisible incipient sprouting (NVIS)

damage.

11

Tetrazolium Test

The tetrazolium test is widely recognized as a valuable means of
estimating seed viability. In Germany in the early 19405 Dr. George Lakon
discovered tetrazolium as a good chemical in determining seed viability. The
tetrazolium chloride or T2 test is often called a quick germination test. The main
function of the tetrazolium test is to distinguish between viable and nonviable
seeds.

In the United States, the T2 test is often used as a complement of the
standard germination test because it allows faster estimates of viability.
Historically the test has been around for many years with early research and
development performed by Lakon (1942), Bulat (1961) and Lindenbein (1961;
1965). This led to the formation of the Tetrazolium committee within International
Seed Testing Association. In 1983, RF Moore presented a handbook to the
ISTA Congress. This manual is the standard that most official seed laboratories
use.

Today the test is used throughout the world as a highly regarded method
of estimating seed viability and is a routine test in many seed testing laboratories.
It is often referred to as a "quick test" since it can be completed in 24 to 48 hours
compared to regular germination tests, which may require up to seven days.

Tetrazolium test results can be extremely valuable for providing
information for immediate quality information on a seed lot followed by a warm
germination test and/or a cold germination test.

12

The tetrazolium test distinguishes between viable or dead tissues of the
embryo on the basis of their relative respiration rate in the hydrated state.
Although many enzymes are active during respiration, the test utilizes the
dehydrogenase enzymes as an index to the respiration intensity and seed
viability. The highly reduced state of the dehydrogenases enables them to give
off hydrogen ions to oxidize colorless tetrazolium salt solution that is changed
into red forrnazan as it is reduced by hydrogen ions. Seed viability is interpreted
according to the staining pattern of the embryo.

Preparation: Two 100-seed replications are soaked in water overnight.
They are then dissected longitudinally so that the embryo is exposed to the
tetrazolium chloride solution. Tetrazolium solution must come in contact with the
embryo. A solution of 2,3,5-triphenyltetrazolium chloride (a salt) is added to
water to form a colorless solution. The seeds are placed in a one percent
solution for approximately two hours at room temperature.

Evaluation: Upon penetration into living cells, the tetrazolium chloride is
reduced by dehydrogenase enzymes present in living tissue to forrnazan, which
is a reddish, water-insoluble compound. The reaction occurs within or near living
cells which are releasing hydrogen in respiration processes. Sound tissues
produce a normal red color. Such tissues resist the rate of penetration of
tetrazolium. The rate of hydrogen release in sound tissues is slow in comparison
to that in partially weakened tissues. Weak living tissues produce an abnormal
color. Such tissues have lost some of the initial resistance to the penetration of
tetrazolium. Respiration is accelerated and forrnazan is produced rapidly.

13

 

During early stages of deterioration, these tissues become darker red (bruised
tissue) more rapidly than sound, healthy tissues. Dead tissues do not stain,
usually remaining white (aged tissue) because lack of respiration prevents
forrnazan production by embryo tissues. The accuracy of results depends largely

upon the training, experience and background of the analysts.

Summagy

Over the last few years, seed analysts at Michigan Crop Improvement
Association have explored several methods to detect nonvisible incipient
sprouting damage. They have observed a relationship between embryo staining
and incipient (nonvisible) sprouting damage, indicating that damage can occur
well before any sprouting effects are visible. In commercial practice, the seed
quality of cereals is judged by the ability of the seed to germinate. Very little has
been reported about the detection of nonvisible incipient sprouting damage and
its consequences on seed quality. It is mainly in this area where this work was

conducted.

14

OBJECTIVES OF STUDY

The objectives of the following studies were to determine the effects of:
1) storage and 2) imbibition period on the laboratory and field performance of wheat

seed.

MATERIALS AND METHODS

Laboratory and field experiments were conducted with two wheat (T riticum
aestivum L.) varieties: one soft white winter variety, Lowell, and the soft red variety,

Mendon.

LABORATORY EXPERIMENT:

Three sets of experiments were conducted in 1995, 1996 and 1997. During the
first year, lots of Lowell and Mendon wheat obtained from Michigan Crop
Improvement Association were induced to produce different nonvisible sprouting

levels described in Table 1.

15

Table 1. Description of sprouting levels obtained after periods of imbibition in
all experiments during 1995 and 1997

 

Imbibition period Description of sprouting levels

 

0 hr Nonsprouted wheat seed (control); no exposure to

moisture imbibition.

15 hr 5-10 percent of seed with nonvisible incipient sprouting.
24 hr 20-30 percent of seed with nonvisible incipient sprouting.
40 hr Visibly sprouted wheat seed, in which the root-shoot axis

has just broken through the pericarp.

 

Seeds were induced to sprout by placing them on moistened blotter paper in a
germination chamber at 22°C and near 100 percent of relative humidity until the
desired sprouting level was obtained. The amount of seed induced was large
enough for both laboratory and field experiments.

After induction, seed lots were air-dried for one week and stored at room
temperature for periods of 0, 2, 4, and 6 months to study the effects of storage on
seed quality when affected by nonvisible incipient sprouting.

At the end of each storage period, seeds were evaluated by the standard warm

germination test, the tetrazolium test, and the accelerated aging test.

16

Four 100-seed replications from each treatment were evaluated by the standard
warm germination test following the Association of Official Seed Analysts Rules for
Testing Seeds (AOSA, 1994) at 25°C for seven days on moist blotter paper.

Two 100-seed replications for each treatment were evaluated by the tetrazolium
test (AOSA, 1970). Treatments were placed in water overnight to allow enough
time for imbibition, after which seeds were sliced and placed in a 1-percent solution
of 2,3,5-triphenyl tetrazolium chloride (TIC) for a period of two hours at room
temperature. The tetrazolium test was conducted according to a classification
method developed by Michigan Crop Improvement Association, which is described
in Table 2. Close-up photographs with a microscope (at 30x and 50x) were taken
of stained embryos in the tetrazolium test to illustrate the appearance of different
levels of incipient sprouting. This pictorial representation is shown in Figure 1.
Normal red color in tetrazolium testing develops when hydrogen ions from
respiration processes of living cells are accepted by the colorless 2,3,5- triphenyl
tetrazolium chloride and reduces it to the red dye forrnazan. White flaccid tissues

are evidence that the unstained tissues are dead.

17

A“ _

 

Viable seed

 

    

Dead seed

Figure 1. Pictorial representation of tetrazolium test evaluation

18

Table 2. Description of classification criteria used for the tetrazolium test

 

 

Levels Description of levels

Viable seed Embryo showing complete staining.

NVIS Embryo showing small unstained areas (usually less
than 1/3).

Dead seed Embryo showing large, critical unstained areas (usually

more than 1/3).

 

Finally, four 100—seed replications for each treatment were subjected to
accelerated aging for 72 hours at 41°C following the ISTA Seed Testing Rules
(ISTA, 1995). Afterward, seed lots were germinated at 25°C for seven days on
moist blotter paper.

Tests were repeated in 1996 and 1997 following the same procedures as in

1995, including germination and vigor evaluation.

19

FIELD EXPERIMENT:
first Year (1995):

In the Fall of 1995, observations were made on the number of hours of moisture
imbibition required to obtain different levels of nonvisible sprouting on two winter
wheat varieties grown in Michigan: Lowell (a soft white wheat) and Mendon (a soft
red wheat).

The first set of experiments was planted in late fall of 1995. Four replications of
Lowell representing all treatments described in Table 1 were planted in 2x2 m
boxes in greenhouse soil at the Michigan State University Hancock Turf Center.
The objective of this experiment was to study the effects of different levels of
sprouted seed lots on soil emergence, perhaps the most important consequence of
preharvest sprouting. Field emergence was measured two weeks after planting.
Unfortunately, due to late planting and a severe winter none of the plots survived

the winter.

Second Year (1996):

Field studies were conducted at the Crop and Soil Sciences Research Farm on
the M.S.U. campus and at Clarksville Horticulture Research Farm, 60 miles west of
East Lansing. Preparation of the different seed lots was timed so the storage

period for each ended at the normal planting time (October 1) for wheat.

20

Once the different seed lots were removed from storage, four replications for
each treatment (Table 1) were planted at both locations for both Lowell and
Mendon. Each replication consisted of 7 rows 6 meters long.

The field experiments were evaluated for field emergence, quantitative index of
spring regrowth potential, and grain yield.

Field emergence was measured 21 days after planting at both locations. Two
rows of plants (one meter per row) were counted for each plot to determine plant
density. Before spring green-up, 90 kg/ha of nitrogen were applied at both the East
Lansing and Clarksville locations. In April 1997, all plots were evaluated and given
a quantitative regrth index. A visual index from 0 to 10 was created, where 0
indicated no regrowth (no plants emerged and/or surviving) and 10 indicated
normal regrth (all plants emerged and surviving the winter). The same index
was used for both locations.

During July 1997, all plots were combine harvested, the grain air-dried and
moisture levels adjusted to 13.5 percent.

Field experiments were analyzed with a completely randomized design. All
data in these studies were analyzed with the SAS Statistical Software package
(SAS Institute Inc., 1997). Because of interactions that occurred, a procedure
called "slicing" was performed. This allowed the study of significant interactions
by analyzing the levels of one factor across all levels of other factors. All tables
describing the statistical analyses and the slicing procedures are placed in the

Appendix and tables numbered A1, A2, etc.

21

Results and discussion

1. Laboratory experiments

a) Letigagolium viability

In 1995, highly significant differences were obtained in tetrazolium viability
among treatments (p > 0.0001). Variety and imbibition period (IP), as well as the
interaction among them showed significant differences in T2 viability ranging
from 73 to 98 percent for Lowell and 63.0 to 98.5 percent for Mendon (Tables 3
and Appendix A1). Fifteen hours of moisture imbibition did not appear to be
enough to reduce viability (measured by the TZ test) in any of the seed lots.
Differences became significant as the imbibition period (IP) increased from 15 to

24 hr, and even larger differences in viability occurred as IP reached 40 hr.

Table 3. Tetrazolium test results (T Z viability) and nonvisible incipient
sprouting (NVIS) of Lowell and Mendon, 1995

 

 

Variety H Imbibition period TZ viability (%) NVIS (%)
Lowell 0 hr 98.00 a 2.50 a
15 hr 96.00 a 10.00 b
24 hr 77.00 b 29.50 c
Mendon 0 hr 98.50 a 2.00 a
15 hr 94.50 a 10.00 b
24 hr 76.50 b 22.00 c
40 hr 63.00 c 35.50 d

 

LSD TZ viability = 3-44

LSD NVIS

=3.13

22

Because of interactions that occurred, the SAS slicing procedure was
performed. High levels of significance (p > 0.0001) occurred in TZ viability
across IP when slicing analysis was performed by variety, e.g., the white variety
Lowell showed highly significant differences across all imbibition periods (Table
A2). No differences in viability occurred among nonvisible levels of sprouting (0,
15, and 24 hr) across the two varieties, while significant differences occurred for
the visibly sprouted level (40 hr) between Lowell (73 percent) and Mendon (63

percent).

In 1996, highly significant differences occurred in T2 viability among
treatments (Tables 4 and A3). Variety, [imbibition period (IP) and storage all
showed highly significant differences in T2 viability (p > 0.0001), while the
interactions between variety and IP, and between storage and IP were also
highly significant (Table A3). TZ viability ranged from 19.0 to 97.0 percent for
Lowell and 34.5 to 97.5 for Mendon (Table 4). Viability decreased for both Lowell
and Mendon as IP increased, while little variation occurred in viability across
storage periods, even though significant differences occurred between 0-2
months and 4-6 months of storage. Finally, TZ viability decreased as IP and
storage period increased, especially for seed lots with higher NVIS (24 and 40 hr
of moisture imbibition).

Commercially acceptable levels of germination/viability were still obtained

after 15 hr of imbibition, with a rapid decrease in quality as the imbibition period

23

continued. Incipient sprouted seed of both Lowell and Mendon with up to 15 hr
imbibition retained viability even if stored as long as 6 months, while visibly

sprouted seed lost viability after 2 months (Fig. 2).

Table 4. Percent tetrazolium (TZ) viability of Lowell and Mendon in 1996

Imbibition Storage period
period ‘ ' ' ‘ ‘ WT’ " T“
Lowell ’ 0 months 2 months 4 months 6 months mean
0 hr 94.50 97.00 95.50 97.00 96.00 a

15 hr 97.00 95.50 91.00 96.00 94.88 a
24 hr 63.00 76.00 70.50 71.00 70.13 b
40 hr 61.50 24.00 22.00 19.00 31.63 c
Mean 79.00 a 73.13 b 69.75 c 70.75 c

 

0 months 2 months 4 months 6 months mean
0hr 93.50 97.50 95.50 97.00 95.88 a
15hr 96.00 97.00 87.50, 97.00 94.38 a
24 hr 69.00 77.00 71.00 71.00 72.13 b
40 hr 74.00 48.50 41.00 34.50 49.50 c
Mean . 83.13 a 80.00 b 73.75 c 75.00 c

Mendon f

LSD (Imbibition) = 2-22
LSD (Storaga) = 2.22

24

 

.-

12mm
°938$§§P3888

 

TZVIabiIin-1996

III

 

222

nor:
‘Iisirl
mm.
In».

 

 

 

 

nadir.
I15ir.

 

0MB

 

 

 

TZViatiIity-1997
andon

      
  

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Figure 2.

The effect of imbibition period and storage on the TZ viability of

Lowell and Mendon in 1996 and 1997

25

 

No significant differences in T2 viability occurred between the non-
sprouted control and seed imbibed for 15 hr, while significant differences
occurred between these two levels and those imbibed for 24 and 40 hr for both
Lowell and Mendon (Table 5). This is consistent with significant differences
noted for each variety across all imbibition periods (Table A4). While no
differences in T2 viability occurred between varieties for 0, 15, and 24 hr of
imbibition, highly significant differences occurred after 40 hr of imbibition.
Mendon had higher TZ viability (49.5 percent) than Lowell (31.6 percent).

Highly significant differences in T2 viability occurred among imbibition
periods (IP) for each storage level as analyzed by the slicing procedure (Tables 6
and A5). Meanwhile, no differences occurred between the non-sprouted control
and seed imbibed for only 15 hr across all levels of storage. Thus, seed lots
retained their viability for up to 6 months of storage even though incipient
sprouting had occurred. It is important to note that the same levels of
significance occurred among IP (Table 6), showing that significant deterioration
occurred during storage, the extent of which depended on the length of

imbibition.

26

Table 5. Least square means for T2 viability of Lowell and Mendon in 1996

 

 

 

 

Variety Imbibition period TZ viability (%) NVIS (%)

Lowell 0 hr 96.00 a 2.38 a
15 hr 94.88 a 8.63 b
24 hr 70.13 b 37.25 c
40hr 31 63 c 26 38 d

Mendon 0 hr 95.88 a 3.00 a
15 hr 94.38 a 9.50 b
24 hr 72.13b 34.13c

LSD 12 viability = 2-22

LSD NVIS = 2.17

Table 6. Least square means for the interaction between imbibition period

 

and storage on TZ viability of Lowell and Mendon in 1996

 

Storage

Omonths "

2863015 ' "

’ 4.3....

6 iiibiitlis”

LSD TZviability = 2-22
LSD NVIS = 2.17

Imbibition
. 1..---.P°Fl°d.-__.__ _.

0 hr
15 hr
24 hr
40 hr

15 hr
24 hr

. “.40 “hi. _

0 hr
15 hr
24 hr

40 hr- e .

0 hr
15 hr
24 hr
4.0m,

94.00 b
96.50 a
66.00 c
67.75 c

96.25 a
76.50 b

. 36.259

95.50 a
89.25 b
70.75 c

97.005
96.50 a
71.25 b

26.759

Tetrazolium
_.--YI_EP.i_'LLY._,I°,/3)

297.25 a

Nonvisible incipient
-m§P.[9“tI”9 (%)

 

3.75 c
5.75 c
41.50 b
50.50 a

10.00 c
36.50 a

.-,--2§.-.99.9W . V

2.25 d
11.75 c
34.25 a

2.50 d
8.75 c
30.50 a

.,_2..1_.__7..5-b._.. .. _,

In 1997, T2 viability decreased with increased storage and imbibition
periods (IP) for both Lowell and Mendon. Highly significant differences in T2
viability occurred among seed lots (Tables 7 and A6) due to the effects of IP and
storage, whereas no significant differences occurred between Lowell and
Mendon. TZ viability ranged from 31.5 to 98.0 percent for Lowell and 21.5 to
96.5 percent for Mendon. The interaction among varieties, IP and length of
storage was significant as determined by the slicing procedure.

No differences in T2 viability occurred from nonimbibed (control) seed lots
of either Lowell or Mendon when tested across storage periods (Table 7),
indicating that nonimbibed seed was able to maintain its viability for at least 6
months. Lowell also showed no differences in viability across storage periods for
up to 15 hr of moisture imbibition, indicating that even though incipient sprouting
had occurred, viability was retained for up to 6 months.

Highly significant differences in T2 viability occurred for both Lowell and
Mendon with increased storage periods as the imbibition period increased from
15 to 24 and 40 hr (Table A7). Though the overall viability at each storage period
did not appear to decrease for Lowell, it did decrease for Mendon, clearly
indicating that different genotypes react differently when exposed to adverse

conditions or stored for different length of time.

28

Table 7. Percent tetrazolium (TZ) viability showing the effects of imbibition
period (IP) and storage on Lowell and Mendon in 1997
Imbibition Storage Period
penod
Lowell 0 months 2 months 4 months 6 months Mean
0 hr. 98.00 97.00 94.00 91.50 95.13 a
15 hr. 96.00 92.00 91.50 92.50 93.00 a
24 hr. 74.50 63.50 65.00 80.00 70.75 b
40 hr. 25.50 28.50 56.50 31.50 35.50 0
mean 73.50 b 70.25 c 76.75 a 73.88 b
Mendon 0 months 2 months 4 months 6 months Mean
0 hr. 96.50 95.50 91.00 91.00 93.50 a
15 hr. 92.00 86.50 89.50 82.50 87.63 b
24 hr. 85.00 64.50 69.00 73.50 73.00 c
40 hr. 44.50 44.00 40.00 21.50 37.50 (I
mean 79.50 a 72.63 b 72.38 b 67.13 c

* LSD (sawmill) = 2.22
LSD (storage) = 2.22

Highly significant differences in T2 viability occurred for Lowell and
Mendon for different imbibition periods (averaged across storage) (Table A7 and
A8). TZ viability of Lowell and Mendon decreased sharply from 90 percent to 70
percent as imbibition increased from 0 and 15 to 24 hr and especially from 24 to
40 hr where the lowest viability occurred (35.5 percent for Lowell and 37.5
percent for Mendon) (Table 7).

Slicing analyses between length of imbibition and period of storage
showed highly significant differences in T2 viability between Lowell and Mendon

after 40 hr of imbibition for all storage periods (Table A9). At 6 months of

29

storage, significant differences in T2 viability between Lowell and Mendon also
occurred after 15 and 24 hr of imbibition, with Lowell performing better than

Mendon at all imbibition periods.

b) W

In 1995, highly significant differences occurred in the level of nonvisible
incipient sprouting (NVIS) among treatments (Tables 3 (page 19), A10 and A11).
Again, differences in NVIS were highly significant among varieties and IP, as well
as their interaction (p > 0.0001), with NVIS ranging from 2.5 to 62.0 percent for
Lowell and 2.0 to 35.5 for Mendon. A visual indication of the sprouting levels
used in all these experiments is shown in Fig. 1. Lowell was the most affected by
sprouting damage, supporting the well-known association between sprouting
susceptibility and the white seed coat color. However, red wheat will also sprout
if high moisture conditions persist long enough.

The percent NVIS increased and T2 viability decreased as the duration of
moisture imbibition increased, indicating that damage due to sprouting had
occurred even though actual damage was not yet visible. This phenomenon has
been described by Sumeola (1965), La Croix et al. (1976) and Sawada et al.
(1995). Gold and Dufus (1995) described it as “pre-maturity alpha amylase
activity,” indicating that important levels of alpha-amylase are produced, reducing

falling number values before any sprouting damage could be observed visually.

30

 

Slicing analyses were also performed on the interaction between variety
and imbibition periods (IP) when levels of NVIS were measured by the T2 test
(Table A11). Highly significant differences in NVIS occurred for both varieties
with increased time of imbibition. The non-sprouted control (0 hr) and the seed
lot imbibed for 15 hr showed no differences in the NVIS across the two varieties,
while significant differences occurred at both the 24 hr (29.5 percent for Lowell
vs. 22.0 percent for Mendon) and at the 40 hr (62.0 percent for Lowell vs. 35.5
percent for Mendon) imbibition periods. Fifteen hr of moisture imbibition did not
appear sufficient to cause any damage due to incipient sprouting for either of the

two varieties.

In 1996, highly significant differences occurred among treatments when
the levels of NVIS were analyzed (Tables 8 and A12). Variety, IP and length of
storage showed highly significant differences in NVIS level when measured by
the T2 test. The 3-way interaction among them was also significant. NVIS
ranged from 1.0 to 54.5 percent for Lowell and 2.5 to 46.5 percent for Mendon.
NVIS damage increased as the IP increased and decreased as the storage
period continued. Some deterioration occurred during imbibition and become
accentuated as the storage period was prolonged. It was clear that most of the
seed with NVIS died during storage, especially that receiving longer periods of

imbibition (Tables 4, 8 and Fig. 4).

31

 

Table 8. Percent nonvisible incipient sprouting (NVIS) for different imbibition
periods and storage of Lowell and Mendon in 1996

Imbibition Storage period
penod " ’i‘ " *
Lowell ' 0 months 2 months 4 months 6 months mean
0 hr 5.00 2.00 1.00 1.50 2.38 d
15 hr 6.50 10.00 9.50 8.50 8.63 c

24 hr 52.00 36.50 30.00 30.50 37.25 a
40 hr 54.50 17.50 19.00 14.50 26.38 b
mean 29.50 a 16.50 b 14.88bc 13.75 c

Mendon 0 months 2 months 4 months 6 months“, mean
0 hi' 2.50 2.50 3.50 3.50 3.00 C
15 I'll' 5.00 10.00 14.00 9.00 9.50 b

24 hr 31.00 36.50 38.50 30.50 34.13 a
40 hr 46.50 34.50 34.50 29.00 36.13 a
mean 21.25 a 20.88 a 22.63 a 18.00 b

LSD (Imbibition) = 2-17
LSD (Storagg) = 2.17

32

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Figure 3. The effect of imbibition period and storage on nonvisible incipient

sprouting (NVIS) of Lowell and Mendon in 1996 and 1997

33

Lowell - TZ test 1996
Seed deterioration during storage with 40 hr of imbibition

100 ,
90 1
so
70
so «
50 1
4o 1
30
20 .
10 .

l I Sprouted seed
I Nonfsproutedseed

°/o Viability

 

. H J
2' . L‘-"J:'
{m m - -
._, ... - m cm

0 months 2 months 4 months 6 months

Storage periods 1

Figure 4. Effect of seed storage on decline of nonvisible incipient sprouting
(NVIS)

The 3-way interaction among varieties, IP and length of storage was
significant (p > 0.0013). The performance of each variety was analyzed across
all IP and levels of storage (Tables A13, A14 and A15). Lowell showed no
differences in NVIS with little or no exposure to moisture imbibition across
storage periods, with values ranging from 1 to 5 percent for the non-sprouted
control (0 hr) and 6.5 to 10.0 percent for seed with 15 hr of imbibition (Table
A13). Significant differences occurred for the 24 and 40 hr of imbibition across

storage periods, with NVIS values ranging from 30 to 52 percent for 24 hr of

34

imbibition and 14.5 to 54.5 for 40 hr of imbibition. For both 24 and 40 hr of
moisture imbibition, NVIS of Lowell significantly decreased after 0 months of
storage, indicating that highly sprouted seed loses its viability within days.
Mendon also showed no significant differences in NVIS across different storage
periods when seed lots were not exposed to moisture, but significant differences
occurred for exposures of 15, 24, and 40 hr across storage periods. No sharp
decreases in TZ viability during storage (as was observed for Lowell) occurred
for Mendon, although the decrease became greater as imbibition period
increased. Highly significant differences in NVIS occurred for all periods of
storage across IP for both Lowell and Mendon (Table A14). As IP increased, the
level of NVIS increased and viability decreased with time of storage. Mendon
showed greater NVIS than Lowell as well as increased viability (Tables 4 and 8),
especially after 24 hr of imbibition and 2 months of storage. It was noted earlier
that red wheat has higher sprouting resistance than white wheat. Though these
data (Table 8 and Figure 3) might appear to contradict those reports, they
actually support them. As the storage period increased, both TZ viability and
NVIS decreased for almost all imbibition periods, indicating that seeds continued
to deteriorate during storage. Mendon seed lots did not deteriorate as fast as
those of Lowell, explaining why a substantial level of sprouted seeds still
remained after 4 and 6 months of storage (Table 8). After 40 hr of imbibition and
0 months of storage, Lowell had 54.5 percent NVIS compared to 46.5 percent for

Mendon. But 2 months later, NVIS level of Lowell dropped to 17.5 percent while

35

that of Mendon rose to 34.5 percent, indicating that the amount of damage and/or
deterioration was larger for Lowell than for Mendon.

Lowell and Mendon showed no differences in NVIS across all periods of
storage for imbibition periods of 0 and 15 hr (Table A15), but highly significant
differences occurred between varieties for 40 hr of imbibition (visible sprouting) at
all periods of storage. At 0 and 4 months of storage, NVIS between varieties
also showed significant differences after 24 hr of imbibition.

Highly significant differences occurred in NVIS among IP across all times
of storage, with the nonimbibed control (0 hr imbibition) having the lowest NVIS.
Unstored seed (0 months) imbibed for 40 hr, had the highest NVIS, but with
extended storage periods (2, 4, and 6 months) seed imbibed for 24 hr had the
highest NVIS. This may be due to gradual death of visibly sprouted seed with
prolonged storage. At the same time, NVIS decreased after 4 months of storage,

possibly due to loss in viability.

In 1997, the percentage of sprouted seed increased with increased length
of imbibition. As damage from sprouting increased (because of more exposure),
nonvisible incipient sprouting (NVIS) decreased with prolonged storage due to
seeds dying during storage.

Highly significant differences in NVIS occurred due to the effects of
variety, storage and imbibition period (IP), as well as the interaction among them
(Tables 9 and A16). NVIS ranged from 6.0 to 55.0 percent for Lowell and 9.0 to
69.5 percent for Mendon.

36

Table 9. Percent nonvisible incipient sprouting (NVIS) for different imbibition
periods and storage of Lowell and Mendon in 1997

Imbibition Storage period
period ’
Lowell ’ 0 months 2 months 4 months 6 months mean
0 hr. 6.50 7.50 6.00 8.50 7.13 d
15 hr. 9.00 16.00 17.00 9.50 12.88 c

24 hr. 34.00 36.50 20.50 55.00 36.50 a
40 hr. 23.00 25.00 53.50 29.50 32.75 b
Mean 18.13 c 21.25 b 24.253b 25.63 a

Mendon 0 months 2 months 4 months 6 monthsw' mean A
0 hr. 9.00 10.00 10.00 8.50 9.38 d
15 hr. 14.50 14.50 14.50 22.00 16.38 C

24 hr. 35.00 33.00 34.00 69.50 42.88 a
40 hr. 37.50 41.50 38.50 21.50 34.75 b
Mean 24.00 b 24.75 b 24.25 b 30.38 a

LSD (imbibition) = 3.04
LSD (storage) = 3.04

No differences in NVIS occurred for either Lowell or Mendon across
storage periods when seed lots were exposed to 0 or 15 hr of imbibition (Table
A17). Highly significant differences in NVIS occurred among storage periods at
the 24 and 40 hr of imbibition for both Lowell and Mendon. As in previous years,
seed lots damaged by NVIS decreased in viability during storage.

Lowell and Mendon showed significant differences in NVIS among storage
levels across imbibition periods (IP) (Table A18). NVIS increased with increased
moisture imbibition, with the largest levels occurring between 24 and 40 hr of
imbibition, depending on the variety. No differences in NVIS occurred between

Lowell and Mendon at all storage periods for nonimbibed seed (0 hr) (Table

37

A19). Neither variety showed differences in NVIS when imbibed for 15 hr at 0, 2
and 4 months of storage. Highly significant differences occurred after 40 hr of
imbibition at all storage periods, with Mendon having higher levels at 0 and 2

months of storage and Lowell having more after 4 and 6 months.

c) Standard Warm Germination Test

In 1996, highly significant differences in germination occurred among
treatments for seed at 25°C on moist blotter paper (Table 10). Variety, imbibition
period (IP), and storage level caused significant differences, as well as the 3-way
interaction among them. There were no differences in germination between
Lowell (84.5 percent) and Mendon (87.3 percent). Germination ranged from 26.3
to 97.0 for Lowell and 52.0 to 96.7 for Mendon (Tables 10 and A20).

No differences in germination occurred for Lowell and Mendon across IP
for unstored seed (0 months) (Table A21), while highly significant differences
occurred for seed stored for 2, 4, and 6 months. Differences in germination
became larger as the IP increased and as storage continued (Table 10).

Lowell showed no differences in germination for the 0 and 15 hr of
imbibition across storage periods (Table A22), while Mendon showed no
differences as storage increased following 0, 15, and 24 hr of imbibition.
Damage caused by moisture imbibition was not adequate to reduce germination
with increased storage, even after longer periods of imbibition. Mendon

appeared to have resisted imbibition damage, probably due to a lower rate of
38

moisture imbibition by the red seed coat. However, significant germination
differences occurred across storage periods after seed lots of Lowell were
imbibed for 24 hr and for both Lowell and Mendon after 40 hr of imbibition.
Greater damage from moisture imbibition occurred after sprouting became visible

and reduced germination occurred with increased storage.

Table 10. Percent germination following different imbibition period and
storage of Lowell and Mendon in 1996

Imbibition Storage Period
penod ’ "
Lowell ’ 0 months 2 months 4 months 6 months Mean
0 hr 95.33 95.00 94.00 97.00 95.33 a

15 hr 93.67 96.67 92.67 93.67 94.17 a
24 hr 87.00 86.00 92.67 80.67 86.58 b
40 hr 91.00 80.00 49.67 26.33 61.75 c
mean 91.75 a 89.42 b 82.25 c 74.42 d

Mendon 0 months 2 months 4 months 6 months Mean
0 hr 94.33 96.00 96.67 95.00 95.50 a
15 hr 94.00 93.00 91.67 94.67 93.33 b
24 hr 86.67 92.00 93.33 88.33 90.08 c
40 hr 88.67 74.00 67.00 52.00 70.42 (1
mean 90.92 a 88.75 b 87.17 b 82.50 c

LSD (Imbibition) = 2.00
LSD (Storage) = 2.00

39

 

Significant germination decreases occurred only for the longest imbibition
period (40 hr) after 4 months of storage, and for 24 and 40 hr of imbibition after 6
months as detected by the slicing procedure across varieties (Table A23). No
differences in germination occurred between Lowell and Mendon across all
imbibition periods after 0 and 2 months of storage and across 0 and 15 hr after 4
and 6 months. At 4 months of storage, differences between the two varieties
became significant and were maintained after 6 months, with Mendon having
higher germination than Lowell. The maximum differences in germination
occurred after 40 hr of moisture imbibition in which sprouting damage became

visible.

In 1997, seed lots of Lowell and Mendon had reduced germination values
as imbibition and storage were prolonged (Table 11). Highly significant
differences in germination occurred due to the effects of imbibition and storage,
however, no differences occurred between Lowell and Mendon. The interactions
between variety and IP, and storage and IP were also significant (Table A24).

Highly significant differences in germination across lP occurred for both
Lowell and Mendon (Table A25). Germination decreased rapidly after 15 hr of
imbibition, reaching values below 50 percent when imbibed for 40 hr.
Nonimbibed Lowell and Mendon showed no differences in germination among

storage periods. Significant differences occurred between both varieties after

40

some imbibition, with Lowell reporting higher germination than Mendon at 15 and
24 hr of imbibition.

Highly significant differences in germination occurred at all storage periods
across imbibition periods (Table A26), indicating that NVIS seed lost germination
potential with increased imbibition. No differences occurred between nonimbibed
seed lots stored for different amounts of time. Differences became significant as
IP increased, with germination decreasing sharply as storage was prolonged.
Lots imbibed for 40 hr and stored for up to 6 months had the lowest germination,

a clear indication of the deleterious effect of storage on NVIS seed.

Table 11. Percent germination of Lowell and Mendon after different periods of

imbibition and storage in 1997
" "AlmbibitionH’ ‘ ‘ Storage Period ' 7

period ' ’ ’ "”5275" " ’ "

Lowell 0 months 2 months 4 months 6 months Mean
0hr. 95.25 94.25 90.50 93.50 93.38 a
15 hr. 95.25 91.25 91.00 89.75 91.81 a
24 hr. 91.25 87.75 84.50 72.50 84.00 b
40 hr. 58.00 50.25 42.25 14.25 41.19 0
mean 84.94 a 80.88 b 77.06 c 67.50 d

Mendon 0 months 2 months 4 months 6 months Mean
0hr. 93.00 92.75 90.00 91.75 91.88 a
15 hr. 88.25 84.00 85.50 83.75 85.38 b
24 hr. 84.00 85.50 81.50 68.75 79.94 c
40 hr. 65.00 59.75 56.50 21.25 50.63 d
mean 82.56 a 80.50 b 78.38 c 66.38 d

LSD (imbibition) = 1-81

LSD (storage) = 1.57

41

 

 

 

 

 

 

 

 

 

 

100 1001
90 90
K) m.
70: , ,7
60‘, 2 limit
50 50 [I15
40‘ 404 in: I
H
30‘ a). _
3: 201 20‘
l
‘0‘ 1o
0' 0.
1m 1m LSJ=1.81
so. 9‘"
an; 50'
7o

‘aonTl

 

gen y .~ (nsnl
. In
E: 5:; 8 L331
8 a). 29‘
2°] 10-
10' o.
0.
Figure 5. The effects of imbibition period and storage on the germination of

Lowell and Mendon in 1996 and 1997

42

 

d) Accelerated aging test

In 1997, the accelerated aging (AA) germination of both Lowell and
Mendon tended to decrease dramatically after imbibition, reaching almost zero
as sprouting became visible following 40 hr of imbibition for unstored seed.
Decreasing vigor occurred with increased time of storage, demonstrating again a
clear interaction of damage caused by sprouting and storage (Table 12). Highly
significant differences in vigor occurred due to the effects of variety, IP and

storage, as well as the 3-way interaction between them (Table A27).

Table 12. Percent accelerated aging germination for different imbibition period (IP)
and storage of Lowell and Mendon in 1997
Imbibition Storage period
period * “ *' “
Lowell 0 months 2 months 4 months 6 months mean
0hr. 89.50 87.75 81.75 87.25 86.56 a
15 hr. 87.50 77.00 67.50 58.50 72.63 b
24 hr. 62.00 43.50 28.25 15.75 37.38 c
40 hr. 2.75 0.50 1.00 0.00 1.06 d
Mean 60.44 a 52.19 b 44.63 c 40.38 d
Mendon 0 months 2 months 4 months 6 months Mean
0hr. 83.00 76.00 69.75 69.00 74.44 a
15 hr. 80.25 54.75 47.50 47.50 57.50 b
24 hr. 46.25 23.00 27.00 12.25 27.13 c
40 hr. 2.00 0.50 0.50 0.00 0.75 d
Mean 52.88 a 38.56 b 36.19 c 32.19 d__

LSD (imbibition) = 1-706
LSD (storage) = 1.706

43

Slicing analyses revealed highly significant differences in vigor for both
Lowell and Mendon at the 0, 15 and 24 hr imbibition periods across all storage
periods. Thus, when NVIS occurred (0, 15 and 24 hr of imbibition), vigor levels
for both varieties sharply decreased during storage (Table A28). For example,
Mendon seed imbibed for 15 hr decreased in germination from 80.3 percent at 0
months of storage to 47.5 percent after 6 months. Meanwhile, no differences
occurred in vigor across storage periods for either variety after 40 hr of imbibition;
their vigor levels were already very low without storage.

Lowell and Mendon showed highly significant differences in vigor at every
period of storage across different imbibition periods (Table A29). Vigor readings
decreased almost to zero as IP increased from 0 to 15 hr and then to 24 and 40
hr. The amount of damage from NVIS appears to have a larger effect than
storage on vigor, although storage effects were still able to reduce vigor following
sprouting.

Lowell and Mendon showed significant differences in accelerated aging
vigor at every storage period when the amount of moisture received was 24 hr or
less. No differences in vigor occurred for seed imbibed for 24 hr after 4 and 6
months of storage. Also, no differences in vigor occurred between varieties for

seed imbibed up to 40 hr following any storage period (Table A30).

44

 

 

Accelerated Aging -1997

 

 

 

Lowell
100 LSD = 1.71
c 90
g 80-
E 70
:35.
3 50 E124 hr.
‘5 40 [140 hr.
o\ 30.
20
10
0 months 2 months 4 months 6 months
Accelerated Aging -1997
Mendon
1001,
g 90f LSD = 1.71
3;. 80'
5 7° l’i’o’hrfi‘
E 60 3.1561.
2 50 ‘624 hr].
< 40 law ml
33 30. .27,-
20
10
o

 

0 months 2 months 4 months 6 months

 

 

Figure 6. The effect of imbibition and storage period on accelerated aging
germination of Lowell and Mendon in 1997

45

2. Field experiments

a) Percent field emergence

In November 1995, four replicates of Lowell were planted in large boxes
of soil under greenhouse conditions. Highly significant differences in field
emergence occurred for the different periods of moisture imbibition (p > 0.0001)
(Table A31 and Figure 4). T-test analyses indicated no significant differences
between the nonsprouted control (0 hr imbibition) and the nonvisible levels of
sprouting (15 and 24 hr), while highly significant differences occurred between
those three levels and the visibly sprouted seed lot (40 hr) (Table 13). Field
emergence (FE) values ranged from 51.2 to 75.8 percent. Regression analyses
showed a significant correlation between nonvisible incipient sprouting (NVIS)
and field emergence, with emergence decreasing 0.445 percent per unit increase
in the amount of NVIS (r2 = 0.445). Based on these preliminary studies,
nonvisible incipient sprouting damage did not appear to affect field performance
as measured by field emergence, even though a large decrease in field
emergence occurred for visibly sprouted seed lots. Due to very late planting and

a severe winter none of the plots survived the winter.

46

Table 13.

18516 111..“ ‘
-_,. -B§[199__._,--_ ,

Field emergence 21 days after planting for Lowell in 1995

Fieldefirgéaegm)

 

 

 

 

 

 

 

0 hr ””” ”’“‘””7bi57"§“
15 hr 75.80 a
24 hr 68.78 a
LSD 0,05 = 7.26
Field emergence -1995
% field emergence vs. % NVIS
100 ¥
90
g so I g
. 70 k
5’ 8
3 6° 0
E 50 - , ’
g 40 i ’
13 :3 . R2 =o.4455 °
.\°
10 »
o : .
o 5 10 15 20 25 30 35
% NVIS
Figure 7. The effect of nonvisible incipient sprouting on field emergence of

Lowell in 1995

47

In 1996, field emergence was largely affected by the duration of moisture
imbibition, damage by sprouting and seed deterioration during storage. Highly
significant differences in emergence occurred in 1996 due to variety, imbibition
period (IP) and storage, but none between locations. Thus, emergence levels for
variety, storage and IP were averaged across the two locations (Table 15).
Significant differences occurred for the interactions between variety and IP and
between IP and storage.

No differences in field emergence occurred among nonvisible incipient
sprouting (NVIS) levels (15 and 24 hr). Seed imbibed for 40 hr emerged
significantly lower than that imbibed for 0, 15 and 24 hr. Emergence ranged from
37 to 90 percent for Lowell and 46 to 88 percent for Mendon. Field emergence
did not decrease as the IP increased from 0 to 24 hr, but decreased sharply
when imbibed for 40 hr (Tables 15 and 16). However, it decreased significantly
as the storage period increased from 0 to 6 months. Significant differences in

emergence occurred among different times of seed storage.

48

Table 14. Field emergence 21 days after planting following imbibition period
and storage of Lowell and Mendon in 1996 at East Lansing and
Clarksville, Ml
Location: East Lansing, MI
Data in percent field emergence
Imbibition Storage period
period ” ’ 7 7 '7 7“
Lowell " " 0 months 2 months 4 months 6 months Mean
0 hr 73.96 75.74 78.75 87.86 79.08
15 hr 87.95 91.82 83.04 80.63 85.86
24 hr 87.05 90.03 70.45 84.64 83.04
40 hr 78.13 50.74 32.95 35.63 49.36
mean 81.77 77.08 66.29 72.19 74.33
Mendon 0 months 2 months 4 months 6 months Mean
0 hr 82.59 84.67 73.13 81.43 80.45
15 hr 81.10 75.74 67.50 77.41 75.44
24 hr 88.69 72.77 74.46 79.82 78.94
40 hr 69.79 57.44 39.91 44.73 52.97
mean 80.54 72.66 63.75 70.85 71.95
Location: Clarksville, MI
Data in percent field emergence
Imbibition Storage period
period * ’ 7 ‘ T
Lowell 0 months 2 months 4 months 6 months Mean
0 hr 89.58 79.76 84.38 84.11 84.46
15 hr 83.33 88.69 80.09 92.68 86.20
24 hr 87.65 81.70 77.95 86.79 83.52
40 hr 78.13 56.70 38.57 38.04 52.86
mean 84.67 76.71 70.25 75.40 76.76
Mendon 0 months 2 months 4 months 6 months Mean
0 hr 73.96 81.70 76.34 69.11 75.28
15 hr 80.80 82.74 76.61 79.29 79.86
24 hr 86.31 84.97 73.66 73.39 79.58
40 hr 78.87 55.95 51.16 58.66 61.16
mean 79.99 76.34 69.44 70.11 73.97

49

 

Table 15. Field emergence 21 days after planting following imbibition period
and storage of Lowell and Mendon in 1996

Average of two locations
Data in percent field emergence

 

Imbibition Storage period
period ’ ’ "
Lowell 0 months 2 months 4 months 6 months mean
0 hr 81.8 77.8 81.6 86.0 81.8 b
15 hr 85.6 90.3 81.6 86.7 86.0 a
24 hr 87.4 85.9 74.2 85.7 83.3 ab
40 hr 78.1 53.7 35.8 36.8 51.1 c
mean 83.2 a 76.9 b 68.3 c 73.8 b
Mendon 0 months 2 months 4 months 6 months Mean
0 hr 78.3 83.2 74.7 75.3 77.9 a
15 hr 81.0 79.2 72.1 78.4 77.6 a
24 hr 87.5 78.9 74.1 76.6 79.3 a
40 hr 74.3 56.7 45.5 51.7 57.1 b
mean 80.3 a 74.5 b 66.6 d 70.5 c

 

LSD (imbibition) = 3-62
LSD (storage) = 3.62

Highly significant interactions occurred between variety and IP, and
between IP and storage (Table A33). Slicing analyses for the interaction
between variety and IP showed high levels of significance for both varieties
across all imbibition periods, with values ranging from 51.1 to 86.0 percent for
Lowell and 57.1 to 79.3 percent for Mendon (Tables 16 and A34).

The interaction between imbibition period (IP) and length of storage was
highly significant. Significant differences in emergence also occurred among the
0, 15, 24, and 40 hr of moisture imbibition at each storage period (Tables 17 and
A35). Highly significant differences occurred in field emergence between the 24

and 40 hr of imbibition across all storage periods, and decreased sharply as

50

storage increased from 0 to 6 months. However, the 0 and 15 hr imbibition
periods showed no differences in emergence across storage periods, indicating
that both nonsprouted seed and nonvisible incipient sprouted seed maintained

emergence capacity in the field.

Table 16. Field emergence following imbibition periods (IP) of Lowell and
Mendon in 1996

 

_,._Y?[i_§‘l¥_.. _. _, .. H 'P M _V .Fl9l93l99’999931.79).

Lowell 0hr 81.8 b
15 hr 86.0 a
24 hr 83.3 ab
40 hr 51.1 c

Mendon 0hr 77.9 a
15 hr 77.6 a
24 hr 79.3 a
_ ‘40.,hr. V." w w , w w W x ._ . .571b .. . . _ . , -_. .. ..._ ..

LSD (emerge). = 3.62

51

 

Field emergence -1996
Lowell

LSD = 3.62

IOhr
.15 hr
024m
EI40hr

% field emergence

 

 

 

 

 

 

0 months 2 months 4 months 6 months

 

 

Field emergence -1996
Mendon

100 ~ LSD = 3.62

a

‘0 hrj‘
:l15 ml
‘024 hi
@4931

% field emergence

 

 

   

 

 

 

 

._ T

0 months 2 months 4 months 6 months

 

 

 

Figure 8. The effects of imbibition period and storage on the field emergence
of Lowell and Mendon in 1996
52

Table 17. Least square means for the interaction between imbibition period
and storage for field emergence of Lowell and Mendon in 1996

 

.53.... .. .. ww..nu....—_.....W..-

 

Storage Imbibition period Percent field
emergence

0 months 0 hr 80.0 b
15 hr 83.3 b
24 hr 87.4 a
2 months 0 hr 80.5 b
15 hr 84.8 a
24 hr 82.4 ab
4 months 0 hr 78.1
15 hr 76.8 a
24 hr 74.1
AA _. .WéO-Wbt-W ,_ _,,, __ ...-..-.._4-Q.§-
6 months 0 hr 80.6
15 hr 82.5
24 hr 81.2
40 hr 44.3

 

 

 

250-111 1» méo O'U'm

LSD 0,05 = 3.62

53

b) Quantitative regrowth index potential

During the months of March and April 1997 an index was used to indicate
the potential of seed lots to establish a crop. With further deterioration, incipient
sprouted seed lots lose the capacity to emerge and produce normal vigorous
stands under field conditions. The reduced seed/seedling vigor, therefore,
results in a reduced stand with reduced vegetative growth with less potential for
winter survival and productivity.

Similar trends as those observed for field emergence occurred in the
quantitative regrowth index. The index decreased with increasing imbibition
periods and prolonged storage (Tables 18, 19 and 20). Highly significant
differences occurred among seed lots due to variety, imbibition period (IP) and
length of storage, but none between locations. Thus, index levels for variety,
storage and IP were averaged across the two locations (Table 19). Highly
significant differences in the index also occurred for the interactions between
variety and IP and between IP and storage levels. Indexes ranged from 1.3 to
8.4 for Lowell and 2.1 to 8.2 for Mendon, with 0 indicating minimum stand and
vigor level and 10 with maximum stand and vigor level.

Lowell and Mendon showed significant decreases in regrowth indexes
across all periods of storage (Tables 20 and A37). Lowell had index values
ranging from 7.84 for unstored seed lots compared to 3.94 for storage periods of
6 months. However, no significant differences in regrowth index occurred
between Lowell and Mendon at any storage period. At 0 months of storage, the

index was 7.84 and 7.75 of Lowell and Mendon, respectively.
54

Table 18. Quantitative index of regrowth potential in the spring of 1997
following imbibition period and storage of Lowell and Mendon at
East Lansing and Clarksville, Ml
Location: East Lansing, MI
Imbibition Storage period
penod ’ 7
Lowell 0 months 2 months 4 months 6 months mean
0 hr 8.00 8.75 5.00 6.00 6.94
15 hr 8.50 8.75 5.75 5.75 7.19
24 hr 8.75 8.25 6.00 5.75 7.19
40 hr 7.75 5.00 1.75 1.50 4.00
mean 8.25 7.69 4.63 4.75
Mendon 0 months 2 months 4 months 6 months mean
0 hr 8.38 8.50 4.63 4.75 6.56
15 hr 8.25 8.25 5.25 4.63 6.59
24 hr 8.00 8.13 4.50 4.75 6.34
40 hr 7.38 5.75 2.25 3.13 4.63
mean 8.00 7.66 4.16 4.31
Location: Clarksville, Ml
imbibition Storage ' period
penod * ”T”
Lowell 0 months 2 months 4 months 6 months mean
0 hr 7.50 7.50 6.00 5.50 6.63
15 hr 7.75 8.00 4.00 4.25 6.00
24 hr 7.75 8.25 4.25 4.00 6.06
40 hr 6.75 4.75 1.25 1.00 3.44
mean 7.44 7.13 3.88 3.69
Mendon 0 months 2 months 4 months 6 months mean
0 hr 6.75 6.00 3.25 4.50 5.13
15 hr 7.75 6.75 3.75 2.75 5.25
24 hr 7.25 8.25 2.75 2.75 5.25
40 hr 8.25 4.75 2.00 2.00 4.25
mean 7.50 6.44 2.94 3.00

55

Table 19. Quantitative index of regrowth potential in the spring of 1997
following imbibition period and storage of Lowell and Mendon
Average of two locations
Data in index of regrowth potential
Imbibition Storage period
period ’ "
Lowell ” ‘ 0 months 2 months 4 months 6 months mean
0 hr 7.75 8.13 5.50 5.75 6.78 a
15 hr 8.13 8.38 4.88 5.00 6.59 a
24 hr 8.25 8.25 5.13 4.88 6.63 a
40 hr 7.25 4.88 1.50 1.25 3.72 b
Mean 7.84 a 7.41 b 4.25 c 4.22 c
Mendon 0 months 2 months 4 months 6 months Mean
0 hr 7.56 7.25 3.94 4.63 5.84 a
15 hr 8.00 7.50 4.50 3.69 5.92 a
24 hr 7.63 8.19 3.63 3.75 5.80 a
40 hr 7.81 5.25 2.13 2.56 4.44 b
Mean 7.75 a 7.05 b 3.55 c 3.66 c

LSD (imbibition) = 0.368
LSD (storage) = 0.368

 

 

 

Table 20. Least square means for the interaction between storage and variety
for the quantitative index of regrowth potential of Lowell and
Mendon in the spring of 1997

Variety Storage Quantitative index

level of regrowth

potential

Lowell 0 months 7.84 a
2 months 7.41 b

4 months 4.00 c

Mendon 0 months 7.75 a
2 months 7.05 b

4 months 3.55 c

6 months 3.66 c

 

 

 

LSD index = 0.368
56

 

 

Index of spring regrowth

   

 

 

 

 

 

 

 

 

 

 

 

Lowell
LSD = 0.37
I0 hr.
a
8 I15 hr.
'0
5 [:24 hr.
0 months 2 months 4 months 6 months
Index of spring regrowth -1996
Mendon
1o
9 . LSD = 0.37
8 .
7 , -7 .
l0 hr ‘
6 - 1
:5 ll15 hr
1: 5 ~ I
E b 1324 hl’
4 j l ,’
|D40 hr}
3 - c ‘ 'i’
2
1
o . ~ , ,
0 months 2 months 4 months 6 months
Figure 9. Index of regrowth potential following imbibition and storage periods

of Lowell and Mendon in 1997

57

Highly significant differences in quantitative regrowth index occurred
across imbibition periods after 2 months of storage and continued with further
storage (Tables 21 and A38). No differences in the index occurred among
imbibition periods for nonstored seed, demonstrating that sprouted seed retains
its capacity to germinate when not stored for long periods of time. However,
highly significant differences occurred in the regrowth index from different
imbibition periods across all periods of storage, even for those that were imbibed

for as little as 15 hr.

Table 21. Least square means for the interaction between imbibition period
and storage for the quantitative index of regrowth potential of
Lowell and Mendon in the spring of 1997

 

 

 

Storage ' Imbibition Quantitative index of
Level Period regrowth potential

0 months 0 hr 7.66 bc
15 hr 8.06 a
24 hr 7.94 ab
40 hr 7.53 c

_- 2months - .. . .. . . .. . - 0hr . _ - _ _, - _ T695 -
15 hr 7.94 b
24 hr 8.22 a
40 hr 5.06 c

"”"“4"r'n"6'riths .. ‘ .. .. . , . . . ”"0"”hr‘ ‘ ,, .- . . . 4225 .. .
15 hr 4.69 a
24 hr 4.38 ab
40 hr 1.81 c
6 months 0 hr 4.63 a
15 hr 4.34 a
24 hr 4.31 a

40hr -___._-_A 1-91 b

 

 

 

LSD 0.05 = 0.368. ..

58

 

c) Grain Yield

The 1997 wheat crop was combine harvested during the month of July.
Data are presented in kilograms of dry wheat per hectare (Tables 22 and 23).

Highly significant differences occurred among the yield of plots planted
with seed from different imbibition periods stored for different lengths of time.
Imbibition periods and duration of storage, as well as the interaction between
them, resulted in significant differences in grain yields (Tables 22 and A39) which
ranged from 2887 to 4884 kg per ha for Lowell and 3052 to 4416 kg per ha for
Mendon.

No differences in yield occurred between the two varieties, with Lowell
averaging 4027 kg per ha and Mendon 3933 kg per ha across all locations (Table
A39). Meanwhile, highly significant differences occurred in yield of plots planted
from seed with different levels of sprouting caused by different periods of
imbibition. Seed lots imbibed for 0, 15 and 24 hr did not perform significantly
different, but differed significantly from those imbibed for 40 hr. Seed lots not
showing visible sprouting produced an average of 4118 kg per ha, while those
with visible sprouting averaged 3568 kg per ha. This is consistent with that of
field emergence and the quantitative regrowth index, demonstrating that
nonvisible sprouted seed retains its capacity to perform well under field

conditions.

59

 

Table 22. Yield (kg/ha) of seed lots following imbibition period and storage of
' Lowell and Mendon in 1997. Average of two locations
Imbibition Storage Period

period “ ' W * *

Lowell 0 months 2 months 4 months 6 months Mean
0 hr. 4335 4242 3911 4026 4129 a
15 hr. 4294 4547 3952 4154 4237 a
24 hr. 4884 4281 3725 4199 4272 a
40 hr. 4399 3652 2938 2887 3469 b
mean 4478 a 4181 b 3631 d 3817 c

Maori 0 months 2 months 4 months 6 months Mean
0 hr. 4339 4013 3911 3636 3975 a
15 hr. 4416 4256 3828 3851 4088 a
24 hr. 4276 4105 3831 3809 4005 a
40 hr. 4205 3954 3452 3052 3666 b
mean 4309 a 4082 b 3756 c 3587 d _

LSD(imblbltion) = 175
LSD (storage) = 175

 

 

 

 

 

 

Table 23. Least square means for the interaction between imbibition period
(IP) and storage on yield (kg/ha) in 1997
Stéiééé‘léiiél’” ""“l'fn‘b‘ibitio’riperiod”“”“Yielddig/Fa)
0 months 0 hr. 4337 b
15 hr. 4355 b
24 hr. 4580 a
40 hr. 4302 b
2 months 0 hr. 4128 b
15 hr. 4402 a
24 hr. 4193 b
__WW4WQ.D-r.,-- . - , , , ..__.-_,_..-.§§9-3W--.9--W . . _ ..
4 months 0 hr. 3911 a
15 hr. 3890 ab
24 hr. 3778 b
40 hr. 3195 c
6 months 0 hr. 3831 b
~ 15 hr. 4002 a
24 hr. 4004 a
LSD 0.05 = 175

60

Highly significant differences in yield also occurred from seed lots stored
for different periods of time, with yield decreasing with increased time of storage
(Table 23). Unstored lots resulted in the highest yields (4394 kg per ha),
followed by those stored for 2 months (4131 kg per ha). Seed lots stored for 4
and 6 months showed no difference in yield at 3698 kg per ha.

In general, NVIS damage did not affect the yield from seed across all
storage periods, though yields decreased rapidly with storage for visibly sprouted
seed. Slicing analyses (Tables 23 and A40) showed that no differences in yield
occurred among periods of imbibition for unstored seed, while highly significant
differences resulted from different storage periods. The results indicate that
sprouted seed could be used for planting if stored for no longer than 2 months.
However, as storage increased from 0 to 2, 4 and 6 months, differences in yield
became significant, with the seed lot imbibed for 40 hr having the lowest yield at
all storage levels. Clearly, the effects of storage on visibly sprouted seed
seriously affected its yield potential.

Highly significant yield differences resulted from seed exposed to different
periods of moisture imbibition across storage periods. Seed lots rapidly
deteriorated after 2 months of storage, including those with NVIS. Differences in
yield increased with increased NVIS and prolonged storage, supporting
previously noted evidence that sprouted seed has reduced performance with

longer storage.

61

 

 

 

 

 

Gnflnthl

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lowe"
LSD = 175

5000

4500 JL a

4000"

3500 I0 hr.
3 3000’ I15 hr.
8 2500‘ [.24 m.
x 2000 [:40 hr.

1500

1000

5004
o - _._..
0 months 2 months 4 months 6 months
Grain Yield
Mendon
LSD = 175
b
i J3— b a at
L .W
c ’IO hl'.
I15 hr
‘024 hr.
law-Ml
L._ l— _
0 months 2 months 4 months 6 months

 

 

Figure 10. The effects of imbibition period and storage on the grain yield of
Lowell and Mendon in 1997

62

 

Discussion and recommendations

Commercially acceptable levels of germination/viability were still obtained
after 15 hr of imbibition, although a rapid decrease in quality occurred thereafter.
Seed of both Lowell and Mendon with nonvisible incipient sprouting (NVIS) after
15 hr of imbibition retained viability for as long as 6 months, while visibly
sprouted seed lost viability after 2 months (Fig. 3).

As time of imbibition increased, TZ viability decreased and NVIS
increased, indicating that damage had occurred even though sprouting was not
yet visible. NVIS damage increased with prolonged imbibition and storage,
especially after 24 and 40 hr.

The white variety Lowell was most affected by both nonvisible and visible
damage, supporting the well known association between sprouting and the white
seed coat color. However, red wheat will also sprout if high moisture conditions
persist long enough. No sharp decrease in T2 viability during storage occurred
for the red variety Mendon (as was observed for the white variety Lowell),
although the decrease became greater with prolonged imbibition.

Although no differences in storability occurred among varieties for
imbibition periods of 0 and 15 hr, our studies show that Mendon stored
significantly better after 24 hr of imbibition. These differences may be due to its
red seed coat color allowing slower imbibition than for Lowell. Consequently,

Mendon was less affected by both nonvisible and visible sprouting damage.

63

Since red varieties incur less damage, the level of deterioration during storage
was smaller than for the white variety Lowell.

Damage caused by moisture imbibition was not adequate to reduce
germination of unstored seed lots, although gen'nination decreased as storage
was prolonged and imbibition increased. Mendon appeared to resist damage
caused by prolonged imbibition more than Lowell, possibly due to its slower
imbibition rate. Imbibition damage largely affected seed performance after
sprouting became visible and increased with prolonged storage.

Accelerated aging vigor of unstored Lowell and Mendon decreased
dramatically with increasing time of imbibition, reaching almost zero as sprouting
became visible after 40 hr of imbibition. Decreasing vigor occurred during
storage, demonstrating again a clear interaction between damage caused by
imbibition and storage (Table 11). However, the amount of damage caused by
NVIS seems to indicate that imbibition influences vigor more than storage.

Laboratory performance decreased as NVIS increased. TZ viability and
standard warm germination decreased with longer imbibition, although no
measurable differences in performance occurred in the field.

NVIS did not affect field emergence, even though a large decrease in
emergence occurred from visibly sprouted seed, indicating that seed with NVIS
could be used for planting if not stored for long periods of time.

Although seed with NVIS retain germinability, field performance
(measured by the spring regrth index) was reduced, even when imbibed for as
little as 15 hr and stored for 2 months or more.

64

Yield results are consistent with those for field emergence and the spring
quantitative regrth index. Thus, nonvisibly sprouted seed retained the
capacity to perform well under field conditions if not stored for more than 2
months. Yield was not affected by NVIS, but only from stored, visibly sprouted
seed.

These results indicate that sprouted seed could be used for planting if
stored for no longer than 2 months. However, as storage increases to 4 and 6
months, differences in yield potential become significant, especially for lots
imbibed for 40 hr. Clearly, the effects of storage on visibly sprouted seed
seriously impaired its yield potential.

Seed lots rapidly deteriorated after 2 months of storage, including those
with NVIS. Differences in yield increased with increased NVIS and prolonged
storage, supporting previously cited evidence that the use of sprouted seed
results in reduced performance after longer storage.

The interaction between imbibition period and variety confirms the
influence of genotype on the susceptibility of a variety to preharvest sprouting. It
is clear that the duration of imbibition greatly affects germination. This interaction
has been reported many times in the literature. Though not specifically shown,
our vigor and field emergence data suggest that performance of seed with NVIS
may suffer under adverse field conditions.

Visible sprouting damage occurred after approximately 30 hr of moisture
imbibition, but NVIS was detected with the tetrazolium test after only 15 hr.
While imbibition period greatly influenced the level of NVIS, it did not

65

substantially affect the T2 test results. This is consistent with the report of Elias
(1987) that sprouted seed maintains its capacity for germination under favorable
conditions.

Performance of seed lots was seriously affected by both the length of
imbibition and storage. However, unstored seed lots maintained their potential
for acceptable laboratory and field performance even though visible sprouting
had occurred. That potential rapidly decreased if storage was prolonged more

than 2 months, especially for visibly sprouted seed.

Recommendations

To assure the maintenance of quality (germination and vigor) of wheat
seed that has been exposed to sprouting conditions, the following
recommendations should be considered:

1. Seed of both white and red varieties can be stored for up to two months even
if incipient visible sprouting has occurred. Growers should be aware that
visibly sprouted seed lots have dramatically reduced vigor capacity, which
can severely reduced field emergence under adverse conditions.

2. Wheat seed with NVIS will also have reduced vigor, which could also reduce

field emergence, especially during storage periods of 6 months or more.

66

 

Appendix

Table A1. Analysis of variance for the effect of imbibition period (lP) on TZ viability of Lowell
and Mendon, 1995

Dependent Variable: TZ viability

 

 

 

 

Source DF Mean Square Pr > F

Model 7 378.63 0.0001

Error 8 4.44

Corrected Total 15

Source DF Mean Square Pr > F
VARIETY 1 33.06 0.0259

IP 3 849.23 0.0001
VARIETY * IP 3 23.23 0.0273

Table A2. Slicing procedure for the interaction between imbibition period (IP) and variety for

TZ viability of Lowell and Mendon in 1995

 

 

 

Sliced by Variety
Variety W 6%----- Mean Square Pr > F
Lowell 3 329.33 0.0001
Mendon 3 543.13 0.0001

 

Sliced by Imbibition period

’ Imbibition period df Mean Square WP???“
0 “r 1 0.25 0.818
15 hr 1 2.25 0.497
24 hr 1 0.25 0.818
40 hr 1 100 0.0015

67

_ ._......~W~_W-~Wmm ..».... . ..

Table A3. Analysis of variance for the effect of imbibition period (IP) and storage on T2

viability of Lowell and Mendon in 1996

Dependent Variable: TZ viability

 

 

 

 

 

Source DF Mean Square Pr > F
Model 31 1235.80 0.0001
Error 32 9.50
CorrectsdI-otal 63..
Source _. DF . ”MeanSquare“”Pr">“T-'
VARIETY 1 370.56 0.0001
IP 3 10790.46 0.0001
STORAGE 3 282.71 0.0001
VARIETY * IP 3 308.19 0.0001
IP * STORAGE 9 408.58 0.0001
VARIETY‘STORA 3 7.60 0.5028
VARI " IP * STOR 9 10.56 0.3827
Table A4. Slicing procedure for the interaction between imbibition period (IP) and variety on
T2 viability in 1996
Sliced by Variety
I Variety Df Mean Square Pr > F
Lowell 3 7273.53 0.0001
Mendon . . 3 , ._ 38.2-31.1- . _. ..- ._-.__.-- . ...-...0-...Q.9_9.1-._- . ._ _
Sliced by Imbibition period
Imbibition period Df Mean Square Pr > F
0 hr 1 0.06 0.936
15 hr 1 1.00 0.748
24 hr 1 16.00 0.204

 

 

 

 

 

 

68

.84..
‘

 

 

 

 

Table A5. Slicing procedure for the interaction between imbibition period and levels of
storage on T2 viability in 1996
Sliced by Storage Level
Storage '8‘}; . . . .. . ....-._V, ”“Dfm ”Md-”MeanSquare W..- WWI-5:; W...
0 months 3 1079.73 0.0001
2 months 3 3254.23 0.0001
4 months 3 3321.83 0.0001
Sliced by Imbibition period
Imbibition period dfw Mean Square Pr > F
0 hr 1 9.07 0.426
15 hr 1 51.42 0.004
24 hr 1 73.75 0.001
40 hr 1 1374.23 0.0001
Table A6. Analysis of variance for the effect of imbibition period (IP) and storage on the T2

viability of Lowell and Mendon in 1997

Dependent Variable: TZ viability

 

 

 

 

 

 

69

Source DF Mean Square ‘ Pr > F
Model 31 1178.74 0.0001
Error 32 9.53

Corrected Total 63

Source DF Mean Square Pr > F
VARIETY 1 7.56 0.3797
IP 3 11131.79 0.0001
STORAGE 3 123.38 0.0001
VARIETY * IP 3 51.60 0.0040
IP * STORAGE 9 163.17 0.0001
VARIETY'STORA 3 139.27 0.0001
VARI.-." .|.P-...‘.‘.'-.--,S..T..QR-,., .9 .. 8076 .__9..Q_Q-Q.1..--..

Table A7.

Slicing procedure for the 3-way interaction among variety, imbibition period (IP)

and storage on T2 viability of Lowell and Mendon in 1997

Effects of VARIETY * IP " STORAGE sliced by Variety * IP

 

 

 

 

 

Variety Imbibition period df Mean Square Pr > F
Lowell 0 hr. 3 17.46 0.1613

15 hr. 3 8.33 0.4646

24 hr. 3 123.50 0.0001

40 hr. 3 404.00 0.0001

Mendon 0 hr. 3 17.00 0.1701
15 hr. 3 33.46 0.0263

24 hr. 3 155.00 0.0001

40 hr. 3 235.67 0.0001

Table A8. Slicing procedure for the 3-way interaction among variety, imbibition period and

storage on nonvisible incipient sprouting (NVIS) of Lowell and Mendon in 1997

Effects of VARIETY * lP * STORAGE sliced by Variety‘Storage

 

 

 

Variety Storage df Mean Square Pr > F
Lowell 0 months 3 2274.33 0.0001

2 months 3 1984.83 0.0001

4 months 3 708.83 0.0001

6 months 3 1660.46 0.0001

Mendon 0 months 3 1133.67 0.0001
2 months 3 1067.46 0.0001

4 months 3 1133.13 0.0001

6 months 3 1952.46 0.0001

 

 

 

7O

Table A9. Slicing procedure for the 3-way interaction among variety, imbibition period (IP)
and storage on nonvisible incipient sprouting (NVIS) in 1997

Effects of VARIETY ' IP * STORAGE sliced by Storage x IP

 

-. . “0*"rfiownths ----.. _._ _. _ - .._ .----- 0hr“ - .. ... . . .- ,, ... - .. . . .- - .._ .

Storage Imbibition period df Mean Square Pr > F

2.25 -- 0.6304
16.00 0.2044
110.25 0.0018
361.00 0.0001

2.25 7 0.6304
30.25 0.0843
1.00 0.7481
240.25 0.0001

--~~~"“gj00"“”“ 0.3385
4.00 0.5217

18.00 0.2044
272.25 00001

0.25 0.8724
100.00 0.0028
42.25 0.0432
100.00 0.0028

 

 

15 hr.
24 hr.
40 hr.

2months"" WW6” W -
15 hr.
24 hr.
40 hr.

4 months 0hr“ -. W. - - . .
15 hr.
24 hr.
40 hr.

6 months 0 hr.
15 hr.
24 hr.
40 hr.

 

 

 

 

. :
' i

 

Table A10. Analysis of variance for the effect of imbibition period (lP) on nonvisible incipient
sprouting (NVIS) of Lowell and Mendon in 1995

Dependent Variable: Nonvisible incipient sprouting.

 

Source DF Mean Square Pr > F

Model 7 830.28 0.0001

Error 8 3.69

CorrectedTotaI W 15

 

Source DF Mean Square Pr > F
VARIETY 1 297.56 0.0001
IP 3 1684.40 0.0001

VARIETY * IP 3 153.73 0.0001

 

71

Table A11. Slicing procedure for the interaction between imbibition period (IP) and variety on
nonvisible incipient sprouting (NVIS) of Lowell and Mendon in 1995

 

 

 

 

 

 

Sliced by Variety
MNflVanety - - . . .. Df Mean Square W..- Pr > F
Lowell 3 1411.00 0.0001
Mendon 3 427.13 0.0001
Sliced by Imbibition period
Imbibition period Df Mean Square Pr > F
0 hr 1 0.25 0.801
15 hr 1 0.00 1.000
24 hr 1 56.25 0.0045
40 hr 1 702.25 0.0001
Table A12. Analysis of variance for the effect of imbibition period and storage on nonvisible

incipient sprouting (NVIS) of Lowell and Mendon in 1996

Dependent Variable: Nonvisible Incipient sprouting.

 

 

 

 

 

 

 

72

Source DF Mean Square Pr > F
Model 31 528.79 0.0001
Error 32 9.05
Corrected Total 63
Source DF Mean Square Pr > F
VARIETY 1 66.02 0.0110
IP 3 4221.77 0.0001
STORAGE 3 260.06 0.0001
VARIETY * IP 3 119.31 0.0001
lP * STORAGE 9 176.77 0.0001
VARIETY*STORA 3 198.43 0.0001
. VARI * IP * STOR - . . -9. .. "374-5- , .- --._-..---9_-0-913----

Table A13.

Slicing procedure for the interaction among variety, imbibition period (IP) and

storage on NVIS of Lowell and Mendon in 1996

Effects of VARIETY * IP * STORAGE sliced by Variety * IP

 

 

 

 

storage on NVIS of Lowell and Mendon in 1996

Effects of VARIETY * IP * STORAGE sliced by Variety‘Storage

Variety lP df Mean Square Pr > F
Lowell 0 hr 3 6.458 0.5509

15 hr 3 4.792 0.6652

24 hr 3 210.333 0.0001

40 hr 3 710.125 0.0001

Mendon 0 hr 3 0.667 0.974
15 hr 3 27.333 0.044

24 hr 3 31.792 0.0261

40 hr 3 109.125 0.0001

Table A14. Slicing procedure for the interaction among variety, imbibition period (IP) and

 

 

 

Variety Storage df Mean Square Pr > F
Lowell 0 months 3 1507.00 0.0001

2 months 3 435.67 0.0001

4 months 3 311.46 0.0001

6 months 3 305.83 0.0001

Mendon 0 months 3 898.83 0.0001
2 months 3 590.46 0.0001

4 months 3 555.46 0.0001

6 months 3 379.00 0.0001

 

73

 

Table A15.

Effects of VARIETY * IP * STORAGE sliced by Storage " IP

Slicing procedure for the interaction among variety, imbibition period (IP) and
storage on NVIS in 1996

 

 

 

 

 

 

Storage lP df Mean Square Pr > F
0 months 0 hr 1 6.25 0.4120
15 hr 1 2.25 0.6214
24 hr 1 441.00 0.0001
2 months 0 hr 1 0.25 0.8690
15 hr 1 0.01 0.9999
24 hr 1 0.01 0.9999
40 hr 1 289.00 0.0001
4months .. Wm“ 1 6.25 0.4120
15 hr 1 20.25 0.1444
24 hr 1 72.25 0.0081
6 months 0 hr 1 4.00 05109
15 hr 1 0.25 0.8690
24 hr 1 0.01 0.9999

40 hr 1 . 210.25 ”9.0091“

Table A16. Analysis of variance for the effect of imbibition period and storage on nonvisible

incipient sprouting (NVIS) of Lowell and Mendon in 1997

Dependent Variable: Percent NVIS

 

Source DF Mean Square Pr > F
Model 31 518.20 0.0001
Error 32 17.77
CorrectedTotal .. . .63 ..

Source DF Mean Square . Pr> F
VARIETY 1 199.52 0.0021
IP 3 3611.14 0.0001
STORAGE 3 136.89 0.0005
VARIET *IP 3 16.10 0.4489
lP * STORA 9 379.92 0.0001
VARIETY*STORA 3 25.93 0.2440
VARI * lP * STOR 9 119.46 0.0001

 

74

Table A17. Slicing procedure for the 3-way interaction among variety, imbibition period and
storage on nonvisible incipient sprouting (NVIS) of Lowell and Mendon in 1997

Effects of VARIETY * IP * STORAGE sliced by Variety * IP

 

 

 

Variety Imbibition period Df Mean Square Pr > F
Lowell 0 hr. 3 2.46 0.9363

15 hr. 3 35.46 0.1344

24 hr. 3 403.00 0.0001

40 hr. 3 397.50 0.0001

Mendon 0 hr. 3 1.13 0.9788
15 hr. 3 28.13 0.2127

24 hr. 3 631.46 0.0001

40 hr. 3 161.83 0.0002

 

 

Table A18. Slicing procedure for the 3-way interaction among variety, imbibition period (IP)
and storage on nonvisible incipient sprouting (NVIS) of Lowell and Mendon in
1997

Effects of VARIETY * lP * STORAGE sliced by Variety'Storage

 

 

 

Variety Storage df Mean Square Pr > F
Lowell 0 months 3 329.46 0.0001

2 months 3 308.83 0.0001

4 months 3 836.83 0.0001

6 months 3 954.13 0.0001

Mendon 0 months 3 412.33 0.0001
2 months 3 447.50 0.0001

4 months 3 397.50 0.0001

6 months 3 1438.79 0.0001

 

75

Table A19. Slicing procedure for the 3-way interaction among variety, imbibition period (IP)
and storage on nonvisible incipient sprouting (NVIS) of Lowell and Mendon in

1 997

Effects of VARIETY * lP ' STORAGE sliced by Storage x IP

 

 

 

 

Storage Imbibition period df Mean Square Pr > F
0 months a 0 hr. 1 6.25 0.5573
' 15 hr. 1 30.25 0.2012
24 hr. 1 1.00 0.8140
_ .. _ .. . 10.???:..... A_ 1. .. 21°25 00016
2 months 0 hr. 1 6.25 0.5573
15 hr. 1 2.25 0.7243
24 hr. 1 12.25 0.4125
,,-_.49_hr-. . . ., . . ._. . e _ . .1 ...... -27225.. ----9-_99-05_---
4 months 0 hr. 1 16.00 0.3497
15 hr. 1 6.25 0.5573
24 hr. 1 182.25 0.0031
40 hr. 1 225.00 0.0012
6 months 0 hr. 1 0.01 0.98930“
15 hr. 1 156.25 0.0057
24 hr. 1 210.25 0.0016
40 hr. 1 64.00 0.0667
Table A20. Analysis of variance for the effect of imbibition period and storage on germination
of Lowell and Mendon in 1996
Dependent Variable: Percent gemiination
Source DF Mean Square Pr > F
Model 31 773.41 0.0001
Error 64 16.30
Corrected Total 95
Source DF Mean Square Pr > F
VARIETY 1 ' H i M "198.38 I ~ ~ M I 0.000973
IP 3 4406.49 0.0001
STORAGE 3 771.63 0.0001
VARIETY * IP 3 110.04 0.0005
VARIETY*STORA 3 115.18 0.0004
lP “' STORA 9 750.48 0.0001
VARI'PSTOR g _ .9. g ._.99-33..,. _. g 00991

76

Table A21. Slicing procedure for the interaction among variety, imbibition period and storage
on germination of Lowell and Mendon in 1996

Effects of VARIETY ' lP * STORAGE sliced by Variety'Storage

 

 

 

 

Variety Storage df Mean Square Pr > F
Lowell 0 months 3 39.64 0.0731

2 months 3 184.08 0.0001

4 months 3 1416.75 0.0001

6 months 3 3231.64 0.0001

Mendon 0 months 3 44.31 0.0519
2 months 3 298.75 0.0001

4 months 3 555.22 0.0001

6 months 3 1268.56 0.0001

Table A22. Slicing procedure for the interaction among variety, imbibition period and storage

on germination of Lowell and Mendon in 1996

Effects of VARIETY ' lP * STORAGE sliced by Variety x lP

 

 

- .,-.\./ar1ebr Imbibition period. Of Mean Square W- P: .>._ I:

Lowell 0 hr 3 4.67 0.8351

15 hr 3 9.00 0.6486

24 hr 3 72.53 0.0067

40 hr 3 2588.97 0.0001

Mendon 0 hr 3 3.22 0.8978
15 hr 3 5.11 0.8155

24 hr 3 28.97 0.1604

40 hr 3 698.75 0.0001

 

77

 

Table A23. Least square means for the interaction among variety, imbibition period and
levels of storage on germination of Lowell and Mendon in 1996

Effects of VARIETY*SPROUTING*STORAGE sliced by Storage x Sprouting

 

 

 

 

 

Storage Sprouting df Mean Square 2 .. Pr > F
0 months 0 hr 1 1.50 0.7626
15 hr 1 0.17 0.9198
24 hr 1 0.17 0.9198
40 hr _ 1 8.17 0.4816
2 months 0 hr 1 1.50 0.7626
15 hr 1 20.17 0.2702
24 hr 1 54.00 0.0734
40 hr 1 54.00 0.0734
4m6"r”iths””0hr - . , WW1.-- 10.67 0.4215.-
15 hr 1 1.50 0.7626
24 hr 1 0.67 0.8404
6 months 0 hr 1 ' 6.00 0.5462“
15 hr 1 1.50 0.7626
24 hr 1 88.17 0.0232
40 hr 1 988.17 0.0001

Table A24. Analysis of variance for the effect of imbibition period (IP) and storage on the
germination of Lowell and Mendon in 1997

Dependent Variable: Percent germination

Source DF Mean Square Pr > F
Model 31 1799.41 0.0001
Error 96 10.14

Corrected Total 127

Source ' DF Mean Square“ " 156""?
VARIETY 1 11.28 0.2941
IP 3 14620.30 0.0001
STORAGE 3 1692.80 0.0001
VARIETY * IP 3 390.30 0.0001
VARIETY*STORA 3 18.59 0.1460
lP * STORA 9 616.85 0.0001
VARI * lP * STOR 9 5.86 0.8117

78

Table A25.

germination of Lowell and Mendon in 1997

Sliced by Variety

“"““"'varery "
Lowell
._ _..--M§DFIQOWWWWW

Sliced by Imbibition period

Imbibition period
0 hr.
15 hr.
24 hr.
40 hr.

Table A26.

1.3.3.3.;Q

‘5wa

Slicing procedure for the interaction between variety and imbibition period (lP) on

 

-o.

on germination of Lowell and Mendon in 1997

Sliced by Storage Level

.....-_...............- .. 0...“... ,. ..

Storage level
0 months
2 months
4 months

- . -5-.."39'..‘.I0$..

Sliced by Imbibition period

048080003;

 

'""'"l"rnbibi"tion period
0 hr.
15 hr.
24 hr.
40 hr.

‘44—‘40-

-h

1817.92
2419.71
2931.20

9392-03.

Mean Square Pr > F
9694.27 0.0001
5316.33 0.0001

Mean Square Pr > F

18.00 0.1858
331.53 0.0001
120.13 0.0009
712.53 0.0001

Slicing procedure for the interaction between imbibition period (IP) and storage

Pr > F
0.0001
0.0001
0.0001

...-Q-.9991- ‘

 

79

Mean Square
23.08
38.45

466.71

3015.11

Pr > F
0.0845
0.0128
0.0001
0.0001

 

 

 

Table A27. Analysis of variance for the effects of imbibition period (IP) and storage on

accelerated aging germination of Lowell and Mendon in 1997

Dependent Variable: Percent accelerated aging germination

...-..n.._~w~4m.—. .. . .- .. .. ,.... .. . ~4W4w-._4..._.. .. ~_.... .. ..-.-.. .. .- ..

 

 

 

 

Source DF Mean Square Pr > F
Model 31 4422.31 0.0001
Error 96 11.82
Corrected Total 127
Source DF Mean Square Pr > F
VARIETY 1 2859.57 0.0001
IP 3 40204.42 0.0001
STORAGE 3 2482.32 0.0001
VARIETY * IP 3 329.32 0.0001
lP * STORA 9 62.97 0.0019
VARIETY*STORA 3 468.17 0.0001
9 86.83 0.0001

VARI * IP * STOR

 

Table A28. Slicing procedure for the 3-way interaction among variety, imbibition period (IP)

and storage on accelerated aging germination of Lowell and Mendon in 1997

Effects of VARIETY * IP " STORAGE sliced by Variety * IP

 

 

 

Variety Imbibition period df Mean Square Pr > F
Lowell 0 hr. 3 44.90 0.0127

15 hr. 3 621.58 0.0001

24 hr. 3 1593.08 0.0001

40 hr. 3 5.73 0.6936

Mendon 0 hr. 3 169.73 0.0001
15 hr. 3 966.83 0.0001

24 hr. 3 805.42 0.0001

40 hr. 3 3.00 0.8584

 

80

Table A29.

Slicing procedure for the 3-way interaction among variety, imbibition period (IP)
and storage on accelerated aging germination of Lowell and Mendon in 1997

Effects of VARIETY * lP " STORAGE sliced by Variety’Storage

 

 

 

 

Variety Storage df Mean Square Pr > F
Lowell 0 months 3 6543.06 0.0001
2 months 3 6169.90 0.0001
4 months 3 5430.42 0.0001
6 months 3 6349.75 0.0001
Mendon 0 months 3 5718.75 0.0001
2 months 3 4472.73 0.0001
4 months 3 3483.23 0.0001
6 months 3 4030.90 0.0001
Table A30. Slicing procedure for the 3-way interaction among variety, imbibition period (IP)

and storage on accelerated aging germination of Lowell and Mendon in 1997

Effects of VARIETY ' lP * STORAGE sliced by Storage * lP

 

 

 

 

81

 

 

 

 

 

 

Storage Imbibition period df Mean Square P'r' > F
""‘“‘“0””r'r?o”r‘iiir§“” 0 hr. '3 1 84.50 0.0088
15 hr. 1 105.13 0.0036

24 hr. 1 496.13 0.0001

40 hr. 1 1.13 0.7583

2 months MMOhrW 1 276.13 0.0001
15 hr. 1 990.13 0.0001

24 hr. 1 840.50 0.0001

40 hr. 1 0.01 0.9999

. 4m0nths _ .. 0hr 1. WWW-zWéé-Oo.-.--.-- 0.0001
15 hr. 1 800.00 0.0001

24 hr. 1 3.13 0.6082

40 hr. 1 0.50 0.8374

. 6months" 0hr""" .. -- T 666.13 0.0001
15 hr. 1 242.00 0.0001

24 hr. 1 24.50 0.1531

 

Analysis of regression for the effect of imbibition period (lP) on field emergence
for Lowell in 1995

Table A31.

Dependent Variable: Percent field emergence

 

Source DF Mean Square Pr > F
Model 1 3385.20 0.0001
Error 62 135.52

Corrected Total 63

 

R-square = 0.287
C.V. = 17.48 percent

Table A32. Field emergence 21 days after planting following imbibition period and storage of
Lowell and Mendon in 1996 at East Lansing and Clarksville, Ml
Location: East Lansing, MI
Data in plants per meter.
Imbibition Storage period T
period . . * . . v —-r
Lowell 0 months 2 months 4 months 6 months mean
0 hr 62.13 63.63 66.15 73.80 66.43
15 hr 73.88 77.13 69.75 67.73 72.12
24 hr 73.13 75.63 59.18 71.10 69.76
40 hr 65.63 42.63 27.68 29.93 41.46
Mean 68.69 64.75 55.69 60.64
Mendon 0 months 2 months 4 months 6 months mean
0 hr 69.38 71.13 61.43 68.40 67.58
15 hr 68.13 63.63 56.70 65.03 63.37
24 hr 74.50 61.13 62.55 67.05 66.31
40 hr 58.63 48.25 33.53 37.58 44.49
Mean 67.66 61.703 ”53.55 f 59-L . _____ -- ..
Location: Clarksville, Ml
.. . Data. [0-918059% meter- -
Imbibition Storage period
period .- -
Lowell 0 months 2 months 4 months 6 months mean
0 hr 75.25 67.00 70.88 70.65 70.94
15 hr 70.00 74.50 67.28 77.85 72.41
24 hr 73.63 68.63 65.48 72.90 70.16
40 hr 65.63 47.63 32.40 31.95 44.40
Mean 71.13 64.44 59.01 63.34
Mendon 0 months 2 months 4 months 6 months mean
0 hr 62.13 68.63 64.13 58.05 63.23
15 hr 67.88 69.50 64.35 66.60 67.08
24 hr 72.50 71.38 61.88 61.65 66.85
40 hr 66.25 47.00 42.98 49.28 51.38
Mean 67.19 64.13 58.33 58.89

82

 

Table A33. Analysis of variance for the effect of imbibition period and storage on field
emergence of Lowell and Mendon in 1996

Dependent Variable: Percent field emergence

 

 

Source DF Mean Square Pr > F
Model 63 0.179 0.0001
Error 448 0.022

Corrected Total 511

Mean Square Pr '>‘ F '
0.086 0.0477
2.323 0.0001
0.466 0.0001
0.118 0.0011
0.002 0.9732
0.164 0.0001
0.038 0.0796

Source

VARIETY

IP

STORAGE

VARIETY " IP
VARIETY*STORA

IP * STORA

VARIE * lP * STORAG

 

come-18380834101?

 

 

Table A34. Slicing procedure for the interaction among imbibition period and variety on
germination across two locations for Lowell and Mendon in 1996

Sliced by Variety

 

Vanety df Mean Square Pr) F
Lowell 3 1.718 0.0001
Mend“ 30722 °~°°°1

 

Sliced by Imbibition period

 

 

* :

imbibition period
0 hr
15 hr
24 hr
40 hr

Mean Square Pr > F
0.049 0.1349
0.225 0.0014
0.052 0.1234
0.116 0.0227

5.3.—34.30.;

 

83

 

 

Table A35.

field emergence across two locations for Lowell and Mendon in 1996

Sliced by Storage Level

 

Storage level
0 months
2 months
4 months

Sliced by imbibition period

 

Imbibition period
0 hr
15 hr
24 hr
40 hr

 

Table A36.

......,_.wwm..- .7. .. .. ..-.._-. ..

Slicing procedure for the interaction between imbibition period and storage on

 

 

df Mean Square Pr > F
3 0.073 0.0192
3 0.607 0.0001
3 1.029 0.0001
3 - . - _. .. .. ..1...1-0--'./-- . .. .. _. ._ . - 0.0001
df Mean Square Pr > F
3 0.004 0.9019
3 0.039 0.1495
3 0.096 0.0044
3 0.819 0.0001

 

Analysis of variance for the effect of imbibition period and storage on the field

performance measured by a quantitative index of regrowth potential of Lowell
and Mendon in 1996

Dependent Variable: Index of regrowth potential

 

 

Source DF Mean Square Pr > F
Model 63 20.905 0.0001
Error 192 1.1 14

Corrected Total 255

Source DF Mean Square Pr > F
VARIETY 1 5.641 0.0256
SPROUTING 3 70.664 0.0001
STORAGE 3 299.737 0.0001
VARIETY*SPROUT 3 7.820 0.0002
SPROUT‘STORA 9 6.014 0.0001
VARIETY*STORA 3 0.372 0.8005
VARIE'SPROUT‘STORAG 9 1.194 0.3850

 

 

 

84

 

Table A37. Slicing procedure for the interaction between storage and variety for quantitative
index of regrowth potential across two locations of Lowell and Mendon in 1996

 

 

Sliced by Variety
Vanety . ._ df . MeanSquare . . .6???
Lowell 3 143.64 0.0001
, Mend90... . 3 V 15347 , ,. , . w -3999!-

Sllced by Storage Level
w‘iuli'rlbfiibition period df Mean Square Pr > F

0 months 1 0.141 0.7228

2 months 1 2.066 0.1748

4 months 1 3.285 0.0875

61110111118 1 -1266 02828

 

Table A38. Slicing procedure for the interaction between imbibition period and storage for
quantitative index of regrth potential across two locations of Lowell and
Mendon in 1996

 

 

Sliced by Storage Level
Storage level ‘3 Df Mean Square Pr > F
0 months 3 0.964 0.4603
2 months 3 34.056 0.0001
4 months 3 27.952 0.0001
6 months - - 3 25.734 M00001

Sliced by Imbibition period

 

 

Imbibition period Df Mean Square Pr > F
0 hr 3 56.776 0.0001
15 hr 3 65.108 0.0001
24 hr 3 74.598 0.0001

85

Table A39. Analysis of variance for the effect of variety, imbibition period and storage on
yield (kglha) in 1997

Dependent Variable: Yield (kglha)

Source DF Mean Square Pr > F
Model 32 333.49 0.0001
Error 219 54.88
__ Qgrrsgtsmtal... . .251
Source DF Mean Square Pr > F
VARIETY 1 123.28 0.1354
IP 3 1043.06 0.0001
STORAGE 3 1627.90 0.0001
VARIET * IP 3 139.24 0.0576
lP * STORA 9 139.34 0.0086
VARIETY*STORA 3 79.62 0.2289
;_VAR| * lP *STOR ___;_9 46.62 0.5714

 

 

Table A40. Slicing procedure for the interaction between imbibition period (IP) and storage
on yield (kg/ha) of Lowell and Mendon in 1997

 

 

Sliced by Storage Level
I Storage level df I. W Mean Square Pr > F
0 months 3 54.82 0.3942
2 months 3 217.97 0.0088
4 months 3 353.18 0.0003
Sliced by Imbibition period
"""‘”I"rh""bibitiorl"”p“eriod ' ' " “ df ‘ ” ’ M‘eeasouere " ' ” " " "”“P‘FSF” ' ' " ’
0 hr. 1 182.79 0.0204
15 hr. 1 229.15 0.0067
24 hr. 1 407.72 0.0001
40 hr. 1 1213.96 0.0001

 

 

86

Wri-

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