Studies on production and flowering in Gladiolus-香川大学学術情報リポジトリ

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Studies on Production and Flowering in Gladiolus

Kiyoshi Kosucr Contents Introduction 2 I Light 4 1 Effect of day-length 4 (1) Effect of day-length on flower bud diffe~entiation 4 Experiment 1 4 Experiment 2 5 (2) Effect of day-length on flower bud development 6 Experiment 3 6 Experiment 4 6 Experiment 5 7 (3) Critical day-length and optimum day-length 8

Experiment 6 8 Experiment 7 8 (4) Effect of light break 10 Experiment 8 10 Experiment 9 11 (5) Critical intensity of supplementary lighting 12 Experiment 10 12 Experiment 11 13 (6) Effect of day-length and temperature 14 Experiment 12 14 Experiment 13 16 Experiment 14 19

(7) Effect of day-length on the formation of corm and cormel, and its relation to blindness 20

Experiment I5 20 Experiment 16 20 Experiment 17 2 1 (8) Effect of day-length on the content of auxin in flower buds 23 Experiment 18 23 (9) Effect of auxin and glbberellin spray on flowering 24 Experiment 19 24 2 Effect of light intensity 2 5 (1). Effect of defoliation 25 Experiment 20 25 (2) Effect of reduced light intensity 26 Experiment 21 26 Experiment 22 2 7 Experiment 23 29 I1 Nutrition and water 31 1. Effect of nutritional treatments 31 (1) Effect of nutritional treatments 3 1 Experiment 24 31 (2). Effect of nutritional treatments of the previous year 36 Experiment 25 36

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Kiyoshi Kosuor

(3) Effect of nutritional treatments to the plants grown from cormel 4 1 Experiment 26 4 1 (4) Effect of nitrogen application on the content of auxin in flower buds 43 Experiment 27 43

2 Effect of soil moisture 46 (1) Effect of continuous dryness 46 Experiment 28 46 (2) Effect of alternation of dry and wet condition 48 Experiment 29 48 (3) Effect of time and duration of dryness 50 Experiment 30 50 I11 Variety and blindness 52 Experiment 31 52 Experiment 32 5 7

IV Anatomical observation 60 1 Observation on the blindness caused by insufficient light condition,

especially by day-length shortage 60

2 Observation on the blind plant caused by nutritional defficiency 60 3 Observation on blindness caused by dryness 6 1

Discussion 6 1

(1) Day-length and flower bud differentiation 6 1 (2). Day-length and flower bud development 61 (3) Light intensity and flower bud development 62 (4) Nutrition and blindness 62 (5) Soil moisture and blindness 63 (6) Variety and blindness 63 (7) High temperature treatment before planting and blindness 63

Conclusion 64

Summary 64

Literature cited 66

Gladiolus is one of the most popular cut flowers in summer. In recent years, year-round production of this plant increased in warmer regions in Japan on ac- count of its various forms, shapes and shades of flower and its strong habit of growth..

Gladiolus flowers well in summer, but not in winter in the northern States of United States, Canada, England, Holland and ,Japan. Blindness is common to gladiolus plants when grown in winter in these countries. Considerable effort has been made by many workers to establish the best method of winter forcing. But the definitive best method has not been found yet.

LOOMIS and

EVANS'^^),

DENNY and his c o - ~ o r k e r s ( ~ - l ~ ) , TSUKAMOTO and his co- WOrkeTS(46, 4 7 4 9 , 5 0 , 5 1 , 5 2 , 5 3 ) _{and APIE(''~) studied about dormancy of gladiolus corms,}

and they reported the methods of hastening the sprouting of corms.. They, however, could not be able to reduce the percentage of blindness in winter.

D E N N Y ' ~ ) found a high percentage of blindness among gladiolus plants which were forced in a greenhouse in winter after breaking their dormancy by treatment with ethylene chlorhydrin vapor.. He concluded that the blindness was not caused

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Studies on production and flowering in gladiolus 3

by the chemical treatment but by insufficient light conditions in the greenhouse in winter. Lengthning the day-length with supplementary lighting, WEINARD and DECKER(^^) were able to decrease the percentage of blindness and increase the pro. duction of early planted gladiolus in a greenhouse. GILBERT and P E M B E R ' ~ ~ ) proved the relationship between the blindness and light by means of lighting and shading the gladiolus LAURIE and P O E S $ I ( ~ ~ ) found varietal differences in the response to light. They reported that only three of the eight varieties tested responded well to light.

On the other hand, LOOMIS and

EVANS'^^), FAIR BURN(^^),

and LAURI~ZEN and WRIGHT

(33) found that high temperature treatment before planting is effective in hastening

flowering, lengthening the spikes and increasing florets. EMSWELLER and TAVERNETTI

(I4) reported effectiveness of heating the soil with electricity in the early stages of

growth

POST(^') described that the blindness is common to gladiolus plants from August to February, and recommended the following treatments for growing gladiolus in the northern States of America.

(1) Plant not earlier than February 1, to avoid low light intensity and short days.

(2). Treat the corms a t 80°F for one month, or a t 102°F for one week, before planting

( 3 ) . Plant a s far apart a s is economically possible, and preferably not closer

than 4 by 6 inches.

(4) Grow a t a night temperature of 50°F during cloudy weather and 55 to 60°F during bright weather.

Generally the use of artificial light is not profitable: but, if artificial light is used, the most logical time for its application is starting when the top of the plant is about 3 inches high, and continuing to April 1.

R U N G E R ' ~ ~ ) stated that high light intensity is necessary for developing flower buds of gladiolus, and if light intensity is too low to develop flower buds, growing points or young spikes of the plants would die This is the case of blindness When light intensity is low and night temperature is high, blindness occurs a t higher percentage The effect of short day resembles that of low light intensity Day.length, however, plays only a subordinate role in the formation of flower

PARKER and BORTHWICK(~~) state that the light break a t midnight with 30 f c. for

30 minutes to 1-30 hours is useful1 to decrease the percentage of blindness.

APTE'~) described that there exists a possibility of finding a variety which will flower under remarkable low light condition without the aid of artificial light,

YASUDA(~') found that dryness of soil and nutritional deficiency also cause the blindness.

TSUKAMOTO and YOKOI(~*) proved the importance of nitrogen, l ~ k e that of day- length, for development of flower buds in gladiolus.

In order to clarify these problems and to decrease the percentage of blindness in winter forcing, the author has been working a t Agricultural Institute of Yokohama

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4 Kiyoshi KOSUGI

National University and later a t Faculty of Agriculture of Kagawa University since 1950 T h e results obtained in these works were reported on Technical Bulletins of the Kagawa Agricultural College, Technical Bulletins of Agriculture, Kagawa Uni- versity, and Journals of the Japanese Society for Horticultural Science. This report dealt with these published results and unpublished, including problems of corm and cor mels production in relation to flowering

Acknowledgements

T h e author wishes to express his heartfelt thanks to Prof. Dr. Yotaro TSUKAMOTO of Kyoto University for his kind valuable advices through all the course of the study for about 10 years.

Sincere thanks are due to Prof.. Dr. Akira KOBAYASHI of Kyoto University, Dr. Taiji KUROKAMI, former Dean of Faculty of Agriculture, Kagawa University, Prof. Dr. Tsuneo EGUCHI of Nippon University, Prof. Hachiro HOSAKA of Chiba Univer- sity, and Prof. Dr. Tadayoshi SUGIYAMA of Tokyo University, for their kindness and advices for the present study.

Many thanks are also due to Prof. Dr. Tadao MAEKAWA, Dean of Faculty of Ag- riculture, Kagawa University and Dr. Bungo MIYAZAWA, for their encouragements. It is also a pleasure to record here the helpful assistance given by Assistant Prof. Kunio KANO and Mr. Tadashi ASAHIRA, both of Kyoto University, Mr. Masaru KONDO of Kagawa Agricultural Experiment Station, and Mr. Yasushi SANO and Mr. Akitoshi SUMITOMO, both of this laboratory.

I. Light

1. Effect of day-length

(1). Effect of day-length on flower bud differentiation Experiment 1 ( 1 9 )

(Experiment of short day treatment in long day condition before flower bud differentiation..)

Materials and methods

Corms of Hector variety were planted in the flat on April 17, 1951, and the short day treatment was given to one half of them from April 20, shading with straw- mats from 5 p.m. to 9 a m. every day, the other half were grown under natural long day condition.

Sampling was made on May 15 from each plot. The sampled materials a r e stored in 70% alcohol, and observed for the stages of flower bud development with binocular by scale stripping method.

Results T h e results obtained are shown in table 1.

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Studies on production and flowering in gladiolus

Table 1 -Effects of short day treatment on the flower bud differentiation in gladiolus (Var Hector, 1951)

INo

of plants/ Average Number of Stages of flower development** Treatment*

1

examined height of foliage I

1

plant

1

leaves

1

111 I I ~

I

III

*

L : long day (natural day length), S : short day (9 hours)

**

IIa, IIb: spike formation stage (IIa: the vegetative point broadens and rises in preparation of the flower formation, IIb: in the axil of the lowermost bract the flower-vegetation-point may be clearly distinguished ), 111: first floret differentiation stage

From the table, it seems that the short day treatment did not affect the flower bud differentiation..

Experiment 2 (Experiment in a dark room.)

Corms of Spotlight variety, 30g in weight, were treated with 30°C for one week, and then allowed to sprout in an incubator a t 25°C. They were planted in Wagner's pots with sand on January 30, 1961, and grown in a dark room of 18°C.

Sampling was made on March 27, 8 weeks after planting. The materials were stored in 70% alcohol, and observed for the stages of flower bud development with binocular by scale stripping method,.

Results

The results obtained are shown in plate 1 and table 2.

Table 2 -Stages of flower bud development in gladiolus grown under continuous dark condition..

(Var . Spotlight, 1960) ~ -I

iment.+

/

No of plantd Height of Number of

/

Length of Stages of flower development**

1 examined plant leaves flower stalk I

/

IIa

/

IIb

/

111

*

A: planted on January 30, 1961 and observed on March 27, 56 days after planting B:

planted on February 6 and observed on May 17, 100 days after planting On the time of observation, all buds were blind

** I : undifferentiation stage, IIa, IIb: spike differentiation stage, 111: first floret differentiation stage

From these plate and table, it is clear that the flower bud differentiation occurs without light.

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Kiyoshi K o s u o ~

(2). Effect of day-length on flower bud development Experiment 3(19)

(Experiment of short day treatment under long day condition.) Materials and methods

Corms of Hector variety were planted in the flat on April 17, 1951. To one half of them, short day treatment was given from April 20. The other half were grown under natural condition.

On May 15, the time of flower bud differentiation, one half of plants in each plot were shifted from long day to short day, while the other half short day to long day. The treatment was continued to July 20.

Results The results obtained are shown in table 3.

By short day treatment after flower bud differentiation, the percentage of blindness increased a little, nevertheless it did not increase by the short day treatment before flower bud differentiation

Table 3 -Effects of short day and long day treatments before and after Boner bud initiation on the flowering in gladiolus

(Var Hector, 1951)

Average date Height of Number of Number of Percentage Percentage ment*

1

$ant

1

leaves florets

lof

flowering

ObE$d

Experiment 4(19)

(Experiment of supplementary lighting under short day condition.)

July,17 9 3 ? 1 1 6

L S July, 10

1

78 7 11 4 S L July, 17

/

94 3 11 4 S S l 92 July, 9 8 2 1 1 1 6

-

% 1 % 10 1

'

89 7

I

l o 3 8 9 i 7 4 7 1 2 5 3 1 0 0 I 9 5 9 4 1 8 2 1 I 81 5 18 5 -.

Corms of Kundard White variety, which were sprouted in a 18°C cell after a low temperature treatment a t 3°C for one month, were planted on September 29, 1951 in the flat and were grown outdoors.

On October 20, they were carried into a greenhouse, and one half of them were lighted supplementally all night with a 100 W incandescent lamp per 3 . 3 m2 from one meter above. The other half were not treated.,

From December 1, the greenhouse was covered with straw-mats from 5 p.m. to 9 a,m. and heated by electric cable every night.

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Table 4 -Effects of lighting on the flowering of gladiolus during autumn and winter season (Var. Kundard White)

No of _{Average date Height of} _{Number of} _{Number of} _Percentage

Pygg:r

1

e e d

1

of o w e r i n g

1

plant foliage florets of flowering

1

plant 116 gCm 8 2 8 6 100.0% 0 %

S Jan. 13 8 4 . 3

1

5 1

1

1.5 6 7 1 9 3 3

*

L : long day, S: short day..

From this table, it is clear that the supplementary lighting in winter increases the percentage of flowering in this variety.

(Experiment of short day treatment under long day condition.)

In this experiment, considerations on the varietal differences in the response to light and shading materials were taken.

Corms of Kundard White and Hector varieties were planted in the flat on April 17, 1952, and grown in a glass house.

In short day plot, shading with black vinyl film was made from 5 p.m. to 8 a.m. every day for 77 days from April 29 to July 15.

Table 5 -Effects of short day treatment on the flowering of gladiolus during spring and summer season

(Vars Hector and Kundard White, 1952)

Treat- ment* S D Cont No of plants examined

Height of Number of Number of Percentage

Pygg:r

plant

ifoliage

leave{ florets

i

of flowering

1

plant

I

1

Kundari White S D 55 1 June, 28

1

105 5 7 8 I 0 5 5 94 5 Cont ₅₇

1

J u l y , 6 1 1 0 6 7 9

1

9 1

,

50 9 49 1 -

-x _SD: _{short day, Cont: control}

From this table, it is definite that short day treatment increases the percentage of blindness, and varietal difference in the response to light exist.

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8 Kiyoshi Kosuor

Table 6 -Stages of flower bud development in blind plant

--

I

Stages of flower development**

I

1

Ira I I ~

1

III

i

IV

1 v

VI-VII Hector

22

White

*

S D: short day, L D: long day

**

I : undifferentiation stage, IIa, IIb: spike formation stage, 111: first floret differentiation stage, IV: stamen formation stage, V : pistil formationstage, VI: ovule formation stage, VII: pollen formation stage

From this table, it is observed that the flower buds of blind plants in the short day plot are aborted a t the stages before pollen and ovule formation, but in the long day plot, the stages aborted are not always the same a s those in the short day plot.

(3) Critical day-length and optimum day-length

(Experiment of March to September, 1956.) Materials and methods

Corms of Picardy, Purple Supreme, Radiance, Spotlight and Vaieria varieties were planted in an experimental farm of Kagawa University on March 16, 1956, and the following treatments were made from May 8.

Plot 1 2 3 4 5

Day-length 8 h r . 10 12 14 16

Natural day-length 8 h r . 8 8 8 8

Supplementally lighting 0 hr. 2 4 6 8

Shading was made to all plots from 5 p..m. to 9 a.m. every day with black vinyl film, and lighting was made with lOOW incandescent lamp for 0, 2, 4, 6 and 8 hours according to the plot by time switch.

From this table, it may be said that optimum day-length for flowering of each variety is a s follows: Picardy: 12 hours, Spotlight: 12 hours, Purple Supreme: 12 and 16 hours, Radiance: 16 hours, and Valeria: 16 hours.

Experiment 7(2 7,

(Experiment of August, 1956 to January, 1957.) Materials and methods

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Studies on production and flowering in gladiolus 9

x Plot 1 2 3 4 5 Day length 8 10 12 14 16hours

Table 7 --Effects of day length on the flowering in gladiolus I. Experiment of March 16 to September 11, 1956.

- --

I

1

]No of plants Percentage

I

Percentage Height of Number of Average Variety I 'lot* examined of flowering _plant

I

O' "lnd

1

plant florets " E n g

I

1

Corms of Picardy, Purple Supreme, Spotlight, and Valeria varieties were stored in a refrigerator a t 5°C from April 9 to August 14, 1956. Then they were planted in the experimental farm of Kagawa University on August 20..

Treatments were made with the same methods as that of the experiment 6, from September 21 to the day of the corm lifting.

20

1

13 2% 20

1

5 7 1 Picardy 100 0

This table shows that the optimum day-length for each variety is a s follows: Picardy: 16 hours, Purple Supreme: 12 and 16 hours, Spotlight: 12 hours, and Valeria: 16 hours. 89 8 % 52 9 0 20 70 9 29 4 7 8 8

1

2 1 2 J u n 29 Jul 5 Jul 10 5 4 99 8 8 95

4cmi

Jul 14 Jul 15 97 5 105 9 98 7 5 8 7 9 6 5 Purple 1

i

20 20 21 1 90 5

1

4.3 J U ~ 2 78 9

I

i;i

9 5 8 0 Jul 11 Supreme

2 1

3 20 100 0 0 Jul 19 87 5 12 5 5 1 0 0 0

1

0 ---- 110 9 9 0 Jul 21 Jul 18 Jun 17 J u n 18 J u n 21 J u n 21 J u n 25

: I

20 20 73. 7 20 64 3 75 9 -- -. 83 3 100 3 8 3 38 9

1

109 1

/

10 9 26 3 35 7 24 1 1 I 20 80 0 95 2 100 0 20 94 4 90 0 105 2 10 4 1 0 9 8 1 1 9 107 2 10 2 20 0

1

99 5 110 8 0 1 0 6 7 4 8 5 9 104 4 -- 5 3 Jul 13 9 4 Jul 12 9 4

I

JuI 16 8 0 Jul 15 12 5 54 5 85 0 85 0 100 0 20 20 20 20 20 -- Valeria 1 0 0 1 0 3 4

/

8 3

/

Jul 18 1 2 3 4 5 87 5 45 5 15 0 15 0 0 86 5 101 0 104 5 104 5 105 6 4 0 Jun. 28 J u n 26 7 3 Jul 29 8 0

1

Jul 3 8 2

1

Jun 30

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10 Kiyoshi KOSUGI

Table 8 -Effects of day length on the flowering in gladiolus

I1 Experiment of August 20, 1956 to January 30, 1957

I

No of plants Percentage P~~~~~~ Height of Number of

'

Average

examined

1

of flowering

/

plant

I

plant florets f l O ~ ~ ~ ~ n g

2 Picardy 3 4 5 2 20 Purple Supr erne 3 20 4 20 5 20 1 20 20 Spotlight

1

20 86 2 4 0 Nov 26 97 6 7 3 Dec 8 97 4 5 1 Dec 9 100 1 9 0 Dec 16 9 4 9

1

4 0

!

Dec.14 Nov. 11 ? ? Dee. 14 Dec 9 Dec 11 Dec 14 Dec. 5 Dec 21 2

/

20 0 Valer ia 3 5

/

20 81 3 --- - - x Plot 1 2 3 4 Day length 8 10 12 14 89 5 9 9 4

I

7 5 Dec 2 66 7 106 2 7 6

1

Dec 9 18 7 1 0 4 4

1

8 6 Dec 10 - -. 5 16 hours

Seasonal changes of the flowering percentage and the optimum day-length were observed.

In Valeria variety, no flowering was observed in 10 and 8 hours plots. So, i t may be said that the minimum critical day-length in this variety exists between

12 and 16 hours.

(4). Effect of light break

Experiment 8

(Experiment of March to August, 1960.)

Corms of Spotlight variety were planted in the experimental farm of Kagawa University on March 13, 1960, and the following treatments were made from May 1 3 to June 20, 1960, for 38 days.

Plot : Control (8 hours day-length). Light break for 1 hour.. Light break for 2 hours. Light break for 4 hours..

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Studies on production and flowering in gladiolus 1 I

Shading was made to all plots from 4-30 p.m. to 8-30 a.m. every day with black vin j l film. Lighting was made with 100 W incandescent lamp from 11 p.m. for 1 , 2 and 4 hours according to the plots.

Results The results obtained are shown in table 9..

Table 9.-Effects of light break under 8 hour day length on the flowering of gladiolus in summer

(Var Spotlight, 1960)

-

-I I I I

!

No of plants Average date Percentage of Percentage of Treatment _examined _{of flowering} _flowering _{blind plant}

Control

/

66 7 %

i

33 3 %

lhr

/

30

1

July 6 27. 3

I

Light 2hr 1 30 I July 10

1

7 2 7 76 2

1

23.8

break 4hr.

1

30 July 12 78. 2

1

21.8

This table shows that the percentage of flowering increased with increasing amount of lighting.

Experiment 9

(Experiment of August, 1960 to January, 1961.) Materials and methods

Corms (5-log) of Spotlight variety were stored in a refrigetator. a t 5°C from March 20 to August 18, 1960, and then planted in the bench with sand in a greenhouse..

Treatments were made in the following procedure from September 28 to Decem- ber 20, 1960.

Plot : Control (8 hours day-length).. Light break 30 minutes. Light break 1 hour. Light break 2 hours.

Shading was made to all plots from 5 p.m. to 9 a.m. every day with black vinyl film.. Lighting was made with lOOW incandescent lamp from 11 p..m.. for 30 minutes, 1 and 2 hours according to the plots.

This table shows that the light break decreased the percentage of blind plant, especially in 2 hours light break plot.

Table 11 shows that the fresh weight of tops in flowered plants is heavier than that of blind plants, although the opposite is observed on the fresh weight of new

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Kiyoshi KOSUGI

Table 10 -Effects of light break under 8 hour day length on the flowering of gladiolus during winter season

-

Percentage Average Average IAverage date Percentage Percentage

/

of u n d i f i r -

1

length of

1

_{length of} Treatment _{of flowering of flowering}

I

0bPa2d

_entiated _blind_stem _{blind spike}

-

I

plant

Control

/

-

1

0 %

1

89 7%

1

10 3 %

1

3 lCm

I

0 SCrn

Table 11 -Effects of light break under 8 hour day length on the fresh weight of top and corm. (Var. Spotlight, Dec 20, 1960)

I I I I

Light 30min 1 Dec 10 1 5 8

'

7 8 9 5 3 11 8 break lhr 0

1

8 3 3

1

1;;

1

4 1 -

I

2hr

1

Dec 30 64 8

1

29 7 24 3 Treatment

1

1 4 0 5 2 5

Total fresh Fresh weight Fresh weight weight of top of new corm

Control

I

Blind plant

/

44 ggrn

/

17. 5gm

/

18 ggm

corms. The total weight of flowered plants is, however, heavier than that of blind plants. 30min 30min Light 1 hour break 2hour 2hour

(5). Effective intensity of supplementary lighting

Flowered plant Blind plant Blind plant Flowered plant Blind plant Experiment 10

(Experiment of March to ,July, 1960.) Materials armd methods

Corms (9-16g) of Spotlight variety were planted in the experimental farm of Kagawa University on March 13, 1960, and treatment was made from May 13 to June 20, 1960. Shading was made to all plants from 4-30 p.m. to 8-.30 a.m. every day with black vinyl film.. Lighting was made all night with a 100 W incandescent lamp, 1.2m above the ground..

This table shows that no differences due to the distance from light were observed in the percentage of flowering, but some delaying in the average date of flowering was observed on the plants near the light. It may be the effect of lighting. From the results, it may be said that the effective distance from light is about two

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Table 12 -Effects of supplementary lighting with incandescent light upon the flowering of gladiolus during summer season

Distance from light

meters (19 lux).

Experiment 11

(Experiment of August, 1960 to January, 1961.)

Light intensity July 11 J u l y 9 July 11 J u l y 8 J u l y 4 July 4 July 3 J u l y 4 lux 50 325 100 100 150 4 1 200

~

19 250 16 300 10 3 50 6 400

1

4

Percentage of

i

Average date flowering of flowering

Natural day length was restricted to 8 hours, and the supplementary lighting was made the remainder of 16 hours % 75 66 54 93 100 79 100 65

Corms (5-log) of Spotlight variety were stored in a refrigerator a t 5°C from March 20 to August 18, 1960, and then planted in the bench with sand in a greenhouse.

Treatment was made from September 28 to December 21, 1960. Shading was made to all plants from 5 p.m.. to 9 a..m. with black vinyl film every day, and lighting for all night was made by a 40 W. incandescent lamp 85 cm above the soil.

Table 13 --Effects of supplementary lighting with incandescent light upon the flowering of gladiolus during winter season

(Var Spotlight, 1960-61)

i I I

Distance from

1

Light intensity Percentage of Average date light flowering

I

of flowering cm 20 60 100 140 180 220 260 300

Natural day length was restricted to 8 hours, and the supplementary lighting was made the remainder of 16 hours % I 700 50 1 January 14 lux 61 168 I January 7 40 23

1

~ a n u a r y 2 18 8 4 2 0 0 0 0 0 - - -

-

0

_I

-

(16)

14 Kiyoshi Kosuo~

Table 14 -Effects of supplementary lighting with incandescent light upon the length of stem and spike in blind plant of gladiolus during winter season

-

-I I I

Distance from _{Light intensity} Length of stem Length of spike light in blind plant in blind plant

Nutritional solution containing 100 ppm N, 50 ppm P and 50 ppm K was applied once a week after sprouting.

This table shows that the effect of light is observed clearly a t the spot one meter (40 lux) from light..

Table 14 shows the results almost the same a s the results shown in table 13. (6). Effect of day-length and temperature

(Experiment of September, 1952 to January, 1953.) Materials and Methods

Corms of Hector variety were stored in a refrigerator a t 3°C from April 10 to September 8, 1952.. Then they were divided into 4 plots: high temperature long day, high temperature short day, low temperature long day and low temperature short day.

On September 10, these corms were planted in the flat and grown outdoor. Then they were carried into two vinyl houses on October 10, and the treatments were begun according to the plots. High temperature plots were heated by electric cable, and low temperature plots were cooled by opening the windows. Long day plots were lighted all night with 100 W incandescent lamps 60 cm above the plants. Short day plots were shaded with black vinyl film from 5 p.m. to 8 a.m.. every day. Samplings were made every 10 days from October 10, and the buds were stored in 70% alcohol. Microscopical examinations were made with binocular by the stripping scale method..

Low temperature plots were transferred to the high temperature vinyl house on December 19, and the same treatment was continued to know the flowering ability.

(17)

Results

The results obtained are shown in tables 15 and 16.

Table 15 shows that the flower buds under long day condition, both in high tem-

Table 15 -Effects of day length and temperature on the flower bud development in gladiolus. (Var Hector, 1952) Treat- ment Date of measurement Oct. 20 High temp Long 20 5 80 6 25 5

dayI

30 5 / 7 7 8 1 5 8 " 9 High temp. Short day Oct. 20 30 Nov. 10 20 30 Low temp. Long day Low temp Short day Oct 20 30 Nov 10 20 30 Oct 20 30 Nov 10 20 30

*

Abbreviation is the same as in table 6

Biginning 5 4 No of foliage leaves 6 5 5 6 8 8 0 5 appeared Stages of flower

1

development*

1

Remark I11

I

IV

1

V V 1 / VII

1

Table 16 -Effects of day length and temperature on the flowering of gladiolus (Var Hector, 1952)

Height of of Number of Percentage Percentage of Treatment*

N~x&!d:d"tsl

plant

1

leaves

1

florets

/

of flowering

1

blind plant

I I I I I L. Ld 79 cm 93 0 88 0 90 9 8 4 8 0 8 2

% I

9 8 6 I % 4 6 7 8 6 21 4 4 0 I 1 4 5 8 1 7 4 7 1 2 5 3 L Sd 70

*

H : high temperature (average temperature during exp was 19 8"C), L : low temperature (16 5°C)

Ld: long day (24 hour day length), Sd: short day (9 hour day length)

(18)

16 Kiyoshi KOSUGI

perature and in low temperature, were developed normally, but under short day condition, flower buds began to abort from 20 days in high temperature and 30 days in low temperature after the treatments were started.

Table 16 shows that no differences were observed on the height of plant, number of leaves, number of florets, percentage of flowering and percentage of blind plant between high temperature plots and low temperature plots, nevertheress, differences were observed on the percentage of flowering and percentage of blind plant between long day plots and short day plots..

Experiment 13

(Experiment of November, 1959 to April, 1960) Materials and Methods

Corms of Atom, Purple Supreme and Spotlight varieties were stored in a refrigerator a t 5°C from March 20 to November 25, 1959. Then they were divided into high temperature plot and low temperature plot. Each group was divided into 5 plots; 8, 10, 12, 14 and 24 hours day-length plot.

On November 28, all corms were planted in the bench with sand in two experimental greenhouses The temperature was kept high in one by heating with electric cable and low in the other.

Treatment was started on December 22 according to the plots. Shading with black vinyl film was made to all plots from 5 p.m. for 0, 2,4, 6 and 16 hours every day.

Nutritional solution containing 100 ppm N, 50 ppm P and 50 ppm K was applied every week after buds sprouted.

Results

The results obtained are shown in table 17, figs. 1 and 2.

Table 17 -Effects of day length and temperature on the average date of flowering in gladiolus (1960)

-- - -- - -

Treatment

1

Varieties --

Temperature

1

Day length

1

Atom

I

Spotlight

/

Purple Supreme

I 14 -

/

Apr 25

j

Apr 28 High*

**

Maximum mean temperature: 25 3"C, minimum mean temperature : 7 6 ° C Mar 24 Mar 26 - Mar 11 Mar 10 14 - 12 24hrs

I

Mar 5 10 Mar 4 8

1

Mar 14 Low** 12 1 A p r 1 3 10

1

A p r 1 2 8

1

Apr 14 1 - -Apr 4 Apr 8 - .- Apr 16 Apr 23 Apr 16 Apr 13 -

1

-

(19)

Studies on production and flowering in gladiolus ,o ,j+%

"-

A t o m

&,I

a0

G O -

<, v,/

'*

40

-

?O

-

%

Percenta9e

o f

b l

loo

-

2 0 Low temp Number o f

.florets

Fig. 1. Effects of day length and temperature on the percentage of flowering, blind and undifferentiated plant and number of florets in gladiolus

, ID 1 0 - p - - - 4 , r ~ ' / I I I

4 -

>

-

L I I I I I / I

I

,

8

10 1 2 14

24

hr8 10 12 14

2 4 h r

8

10 12 14 2 4 h r

Day

l e n f t h

D a y

Lenqth

Day

Len@

h

(20)

18 Kiyoshi Kosuor

Heiyht of f l o w e r e d p l a n t

-I

,.-.I,.

-

_{L ~ t}

_{Purple Supreme}

Height o f

u.nf

,-' L O W

t e m p

Number of leaves, f l o w e r e d .

plant

*--*.---#v

8 10 12 14 24hr.8 10 12 14 24hr 8 10

Day

len$th

Ddy L e n y t h D a y l e n y t h

Fig 2 Effects of d a y length and temperature on the height of plant, number of leaves and length of stalk with blind flower in gladiolus

Table 17 shows that earlier flowering was observed in high temperature plots than in low temperature plots and in short day plots than in long day plots.

Fig. 1 shows the following results.

(21)

in high temperature plots, especially in shorter day-length, although varietal differences were observed.

(2). Percentage of blind plant was high in less flowering plots.

( 3 ) There was no difference in percentage of undifferentiated plant among the plots.

( 4 ) On the number of florets, similar tendency to the flowering was obtained. Fig.. 2 shows the following results.

(1). The plants in high temperature plots were taller than those in low temperature plots.

(2). No differences were observed in the number of leaves.

(3). No differences were observed in the stem length of blind plants in Purple Supreme and Spotlight varieties, except Atom variety in which longer stems were observed in high temperature of 24 hours day-length plot.

Experiment 14

(Experiment of November, 1959 to May, 1960..)

For the reference to practical cultivation, this experiment was conducted. Materials and methods

Varieties used were Friendship, Bo-peep, Han van Meegeren, Red Botton, and Elizabeth the Queen. Corms of these varieties were divided into two plots. One was high temperature plot and the other was low temperature plot.

On November 30, 1959, corms were planted in the bench with sand in two experimental greenhouses. The temperature was kept high in one and cool in the other.

Table 18.-Effects of temperature on the flowering of some varieties forced during winter (1960)

No. of

plants Average date Percentage Percentage Percentage No of Height No of 'lot*

1

examined of flowering

1

of flowering

1

":"::o f d florets of plant

1

leaves

Apr. 23

I

7 1 1 8 7

1

0

I I

1

Elizabeth the Queen

H 19 Mar 11 1 0 0 0 125 6 I 1 1 4 L

1

18 A p r . 1 7

1

9 4 4

1

g . 6

1

1 7 . :

I

I 0 8 1 1 1 4

I

1 I Han van ~ e e ~ e r k n 0

:t

A

1

25.0

1

I00 75.0 0 0 0 7 6 9;2 1 7 0

(22)

20 Kiyoshi KOSWGI

After the buds sprouted, nutritional solution containing 100 ppm N, 50 ppm P and 50 ppm K was applied every week and weaker buds were removed leaving a strong bud on each corm.

Results The results obtained are shown in table 18. This table shows that:

(1). About one month earlier flowering was obtained in the plants of high temperature plot than in the plants of low temperature plot.

(2). No differences were observed in the percentage of flowering and number of leaves.

(3). Varietal differences were observed.

(4). More florets were observed in low temperature plot than in high temperature plot.

(5). The plants in high temperature plot were taller than those in low tempera. ture plot.

(7). Effect of day-length on the formation of corm and cormel,

and the relation to blindness.

Experiment 15. (March to September., 1956)~'~) Experiment 16. (August, 1956 to January, 1957.)~'~)

Materials and methods (see the experiments 6 and 7.)

Results

The results concerning the formation of corm and cormel were shown in figs. 3,

t i i z i ; ; i2i:i i i i i i i i i i i

(23)

-2nd EXP

6%.

"'I

Variety Picardy Purple Radianco Spotlight Valeria

Supreme

Fig 4 Weight of new corms Plot 1 2 3 4 5 Day length 8 10 12 14 16hr..

Variety Picardy Purple Radiance Spotlight Valeria

Supreme

Fig 5 Number of cormels per plant

2 P,

i

z B 2 5 2' 5 1 2 3 ; ; Variety Picardy 1st EXP

!I/

n ieSib

Purple Radiance Spotltght i 2 3 4 k i 2 i j ? W Valeria

Supreme

Fig. 6. Total weight of'cormels per plant.

-

2 ?. g 1st EXP (Spnngf 2 a n ~& + r n A ~ ~ p'ota 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

Varioty Picardy Purple Radiance Spotlight Valeria

Supreme

Fig. 7 . Weight of' cormel

4, 5, 6 and 7.

These figures show differences in the formation of cormels, but not in the corms in the plants grown under different day-length.

Experiment 17.

(24)

22 Kiyoshi Kosuor

Corms of Spic and Span variety were stored in a refrigerator a t 5°C from the end of March to August 20, 1956, and planted in the experimental farm of Kagawa University.

Samplings were made every two weeks from September 17, 1956, and new corms were measured.

On the other hand, corms of the same variety were planted in the farm on March 21, 1957.

Samplings were made every two weeks from May 20, 1957, and new corms were measured.

Results

The results obtained are shown in table 19 and fig. 8.,

May

June

Jllly Au%

Sept.

17 1 15 29 12 26 10 24 7

Sept. Oct. Nov Dec Jan.

Fig 8 Effects of planting time on the growth of new corm of gladiolus (var Spic and Span) Flowering percentage was 95% in spring and 30% in autumn

Table 19 -Effects of planting time on the yield of new corm and cormels (Var Spic and Span, 1956-57)

--

Table 19 shows t h a t :

(1). No difference was observed in the height of plant between the plants sown

Time of No of plants Percentage Height of New Corm planting

1

_{mother corm}

I

examined of flowering

1

_{p a n t}

No

1 92,

-.

in spring and in autumn..

(2). T h e flowering percentage of the plants sown in autumn was half of that in spring.

(3). Almost the same number of new corms were obtained in both plots, but the

Cor me1 No. Weight Spring Autumn 17 5gm

/

19 93 4Cm 34 615 4gm 18 1 3 8gm 1 7 7

~

15

/

50

1

9 0 3 2 6

1

if337 8 1 1 2 -

(25)

total weight of new corms in spring sown plants was heavier than that of autumn sown plants.

Fig.. 8 shows that the growth of new corm in spring sown plants increased rap- idly after fading of flowers, but the rate of growth in corms of autumn sown plants was constant from the time of sprouting to the digging time.

(8). Effect of day-length on the content of auxin in flower buds Experiment 18(25)

(Experiment of August to November, 1958.) Materials and methods

Corms of Spotlight variety were divided into long day plot and short day plot, and then they were planted in the experimental farm of Kyoto University on August 27, 1958. All night lighting with a lOOW incandescent lamp per 16'm2, 1.5 m above the ground and shading with black vinyl film 5 p.m. to 9 a.,m. every day, were made from October 10 to November 6.

Samplings were made every week during the course of the experiments and the avena tests were made on each sample. Auena satiua, variety Victory grown a t Hokkaido University was used for the curvature test. T o determine the auxin con- tent, the diffusion method, diffusing to agar block for 3 hours a t 25°C) was em- ployed..

Results

The results obtained are shown in tables 20, 21 and 22.

Table 20. -Effects of day length on the height of plant, number of leaves, length of stem, and length of spike in gladiolus.

.- .

-I I I I I

Number of leaves

Treatment Length of' _stem

1 ,

Length of _spike Before treatment

/

Oct 9

1

73 4cm

-- ...-- --

/

O c t 1 6

1

7 8 7 Date of measurement Height of plant Long day

Table 20 shows that; two weeks after the start of treatment, it was observed that the length of flower spikes in short day plot was getting shorter than that in long day plot, nevertheless no difference was observed between long day and short day plot in the height of plants, number of leaves, and length of stems. The difference

Oct 21 79. '7 9 2 8 69 1. 17&0. 12 Oct. 30

1

8 3 1 1 0 1

1

2 0 2 0 2 2 i a 0 3 2

I

N o v . 6

1

95.6

/

11.2 Short day - -- Oct 16 Oct 21 Oct 30 Nov 6 - -78 8

1

8.9 8 4 5 9 3 86 6

,

10 3 9 0 0 1 10.5

(26)

24 Kiyoshi Kosucr

in the length of spike increased gradually a s the time progressed. Finally, the blindness occurred in short day plot, four weeks after the start of treatment.

Table 21.-Comparison between the auxin contents in the flower spike in gladiolus grown under long and short photoper iod

Date of Avena curvature (")

- - I A A

measurement Long day Short day (0.2 P P ~ )

1

(bud14 agar) (budfi agar) Oct 9

1

Before treatment 32 17&2 77

*

budlone agar

**

0 4 ppm Oct 16

Oct 21

Table 21 shows that; the value of avena test with the plants under short day condition was smaller than that under long day condition two weeks after the start of treatment. As the time progressed, the difference in the measurement values between long day and short day plots became greater. Finally, only few avenas were curved with the plants under short day.

Table 22 -Comparison between the auxin contents in the flower spike of same length taken from plants grown under long day and short day

Date of Avena curvature (") - - -. . -

measurement Long day I Short day I

I

(budlone agar)

1

(budlone agar) I Remark

I

- Oct 30

1

11 7 5 2 2 79

1

10 14-15 32 I I 8mm cut 29 50-13 61 33 08-14 38 N o v 6

1

2 5 2 0 - 1 4 0 9 1 5 0 0 - 1 3 9 3

1

lOmm cut 16 92-12 30 15 50-12 92 (32.50-14 12)* I (31 57&5 2 4 ) ~ 24 75&8 46 I 19 50&7 41 ( 3 2 4 3 & 4 7 2 ) * I ( 2 6 3 0 k 4 6 4 ) K Oct 30 18 33-11 44 (25 5 6 2 3 53)"" Nov 6

1

32 44-15 10

Table 22 shows almost the same results a s obtained in table 21.

30 OOk5 46 I 2 2 2 2 1 4 2 2 27 3 0 k 4 09

1

8 7 8 1 3 5 9

(9). EfTect of auxin and gibberellin spray on the flowering of gladiolus

Experiment 19

(Experiment of IAA and GA spray.) Materials and methods

Corms of Purple Supreme were stored in a refrigerator a t 5°C from March 20 to August 26, 1959. Then they were divided into 14 plots a s follows: dipped the corms in the solution of 100 and 50 ppm gibberellic acid for 16 hours before planting, sprayed the plants with solution of 100, 50, 20 and 10 ppm GAY sprayed the plants with solution of 100, 50, 20 and 10 ppm IAA, and sprayed the plants with solution

(27)

of IAA 10 ppm prus GA 50, 20 and 10 ppm every week from September 22 to November 17. Planting was made on August 27, 1959.

*

Spraying was made every week from Sept 22 to Nov 17, 1959

*a Dipped in the solution of gibberellin for 16 hours before planting

Table 23 -Effects of gibberellin on the percentage of blind plant in gladiolus

No of plants Percentage P ~ Number of ~ ~Height of { Number of ~ ~

Treatment e x a m i n e

i f

o w e i n plant florets

1

plant leaves

From this table, it seems that the spraying of high concentration of IAA and GA increased the amount of blindness, nevertheless, the spraying of IAA 20 ppm solution was effective more or less to reduce the percentage of blindness.

2. Effect of light intensity (1). Effect of defoliation 6 3 7 1 6 5 66 7 l7 Spray* GA lOOppm 50 20 Experiment 2 0 . ( ~ ~ ) (Experiment of May to August, 1955..)

15 18 14

Corms of Golden Cup variety were planted on May 18, 1955, and the leaf blades of the plants were cut off from lower leaves to upper leaves continuously according to the plant growth, leaving 2, 3 and 4 of the leaf blades by the plots..

88

gem

92 7 93.9

8 9 9.2 9 6 87.0

i

21 7 1 4

,

7.1 [ 6.4 10 14 9.5 Dip** GA 100

1

22 50 0 31.8 6 9 92 8 9 1 50

1

20

/

45.0

1

50.0

1

6 . 5

1

90.0

1

8 6 Spray*IAA 100 50 20 10 Spray* GA

+

IAA 50f 10 20i-10 lo+-10 Control

1

17

1

7 0 6

/

2 9 4

1

6 8

1

9 2 9

1

9.0 18 13 15 14 16 19 15 44 4 16 7 46 2

,

38 5 93'3 6.7 21.4 71. 4 7. 2 7 3 7.8 7.5 6 5 5 6 5.0 50 0 63 2 46. 7 37 5 31 5 26 7 92 0 89 8 99 3 96.8 84 7 92 9 90.8 9 2 8. 5 9 8 9. 5 8. 1 9 4 9. 3

(28)

26 Kiyoshi Kosuor

This table shows that no difference was observed in the percentage of flowering, between the plants of defoliated plots and check plot, and no blind stalk was ob-

Table 24 -Effects of defoliation on the flowering in gladiolus. (Var Golden Cup, 1955)

Treatment (number No of plants _Percentage _{Average date} _{Height of} _{Number of}

) examined of flowering of flowering plant florets

served in these plants,

(2). Effect of reduced light intensity

9 4

10. 7 9 9 7. 4

(Experiment of reduced light intensity in summer.)

No defoliation 4 leaves 3 leaves 2 leaves

July 24 July 24 July 26

Corms of Hector, Picardy, Radiance and Yellow Herald varieties were planted in

cm 80 1 83 0 78 9 15 15 15 15 July 24 70 5 % 100 100 100 100

(37.9%), D: shaded by marsh-reed screen (23 3 %)

Table 25 -Effects of light intensity reduction on the flowering in gladiolus during summer season.

--- (1955) -

-I

Average date Percentage Number of Height of Number of 'lot* _{of flowering} _{of flowering} _florets _plant _leaves

A B C D Hector 100%

-rI5

5 100 14 7 13 6 loo loo

1

12.4 ---- -- June 29 June 30 June 30 July 7 106.8 113 4 117 6 115.1 A B C D A 7 9 7 8 7 7 7.8 120 1 116.2 122 7 120.7 104 3 113 2 110 0 8 6 8 5 8 6 8. 7 _- 7 3 7.0 7 5 June 27

1

100 13 3 1 0 1 1 5 D 11.0 Yellow Herald A B C D 106.5

1

6.5 Picard y 13 0 11 8 13 0

I

July 8 July 11 July 10

*

A: natural light intensity (loo%), B: shaded by vinyl film (66 7%), C : shaded by oil paper June 25 June 25 100 100 100 July 12 100 1 11.2 100

/

16 1

I

112 2

/

Radiance June 27 100 10 7 100 15 1 June 24 100

1

15 6 June 24

I

100 12.8 110 8 7. 2 104.7

1

7.1

(29)

the flat on March 29, 1955, and shaded by vinyl film (light intensity was 66.7% to the check), oil paper (37.9%), and marsh-reed screen (23.3%) with the plots, from 8 a.m. to 5 p.m. every day for a period from May 20 to June 29, 1955.

This table shows that no difference was observed in the percentage of flowering between the treated plants and the check plants, and no blind stalk was observed in these plants.

(Experiment of reduced light intensity in autumn and winter..) Materials and methods

Corms of Picardy and Yellow Herald varieties were stored in a refrigerator a t 0-,5"C from April 1 to August 24, 1955, and then planted in the flat on August 26. They were shaded by vinyl film (light intensity was 49.4% to the check), oil paper (31.5%), and marsh-reed screen (20.5%) with the plots all day long from Septem- ber 20 to December 20, 1955. And supplementalry lighting was used to eliminate the influence of short day.

Results

The resurlts obtained are shown in tables 26, 27, 28, 29 and fig.. 9.

Table 26 -Effects of light intensity reduction on the flowering in gladiolus during winter season (exp I)

(\Tar Yellow Herald, 1955)

No' of Average datt Plot*

1

_examinedplants

/

_{of flowering}

Percentage Percentage of blind flowering*" plant A B C D Number of florets Dec 5 33 Dec. 7 33 Dec. 8 30

I

Dec 17 Height of plant I - -cmi 1 1 6 4

/

Number of leaves

*

Abbreviation is the same as in table 25

a+ Including unflowered plants

Table 26 shows that, in Yellow Herald variety, no difference was observed in the percentage of flowering between the treated plants and the check plants, except a very little amount of blindness in the marsh-reed screen plot.

Fig. 9 and table 27 show that, in Picardy variety, plant was not bloomed because the temperature was too low for this variety. And in this variety the amount of normal flower buds were decreased and undifferentiated plants were increased as the light intensity decreased. No difference was observed between the treatments on the percentage of blind stalk, except marsh-reed screen plot, in which very few

(30)

28 Kiyoshi KOSUGI

blind plants were observed.

From these results, it seems that the light intensity is not the main factor to the cause of blindness in gladiolus, as far as these experiments were concerned.

o

Undifferentiated

Blind

E

Normal

f l o w e r

_--_ -._ _-.-/ --,-- -v

Control Vinyl film Oil paper Marsh-reed screen

Fig. 9. Effects of light intensity reduction on the flowering in gladiolus during winter season (var Picardy, Dec 20, 1955)

Table 27 -Effects of light intensity reduction on the flowering in gladiolus during winter season (exp 11)

(Var Picardy, 1955)

Plot*

Percentage of Percentage of plant

I

Percentage of

I

undifferentiated with nor ma1 flower

1

blind plant _plant

B

C

D

*

Abbreviation is the same as in table 25 21. 6 19 0 4 4 36 1 42 3 24 0 57 0 5 3 I 90 3

(31)

Table 28.--Seasonal changes in light intensity at Kagawa. (Dec.. 1954 to Nov.. 1955) -- - Date of measurement Dec. 17, 1954 ,Jan. 16, 19.55 Feb. 23 Ap r.. 13 May 14 June 22 ,July 18 Aug. 15 Sept.. 12 Oct. 12 Nov. 1.5

Sum value of a day*

*

Sum of hourly values in lux in a day

**

Shown as per cent that on July 18

Table 29 -Light intensity under different shading materials in the morning and the evening

Experiment 23

(Experiment of July to October, 1960.) Materials and methods

Time observed 4-00a m 15 30 45 5-00 6-00 7-00

Corms (8-.13g) of Spotlight variety were stored in a refrigerator a t 5°C from March 20 to July 11, 1960. They were divided into two groups of natural day length and short day (8 hours) length, and each of the groups was divided into four. plots. The four plots are check plot and plots shaded with one, two and three fold black victoria lawn.

Control 0 2 17 198 480 4,400 73,000

Vinyl film Oil paper Mar sh-r eed _screen

T h e corms were planted in the bench with sand in the experimental greenhouse

6-00p m 7-00 15 30 45 8-00 0 0 5 53 110 900 7,300

I

0 0 0

I

O

Sunrise: 4-53a m , and sunset: 7-lop m (June 28, 1955 at Takamatsu, Kagawa) 11 112 27 5 2,750 35,000 310 260 53 13 7 73 170 1,700 9,000 40 5 385 92 26 1,700

/

825 I 1,270 190 77 6 7 50 133 33 0 O I 0

I

0

I

p0

(32)

-30 Kiyoshi K o s u ~ r

of Kagawa University on July 14, 1960. Treatments were began on August 15. In the short day plots, shading was made from 4-30 p.m. to 8-30 a.m. by black vinyl film every day. After the buds were sprouted, nutritional solution containing 100 ppm N, 50 ppm P and 50 ppm K was applied every week. The natural day-length

10 \

B

100- 9 0 N u n b e r o f leaves WhoLe plant 6 0 5 0 Height o f plant 40 \ 30- \ \ &.-_ 20- -* 8 0 60 =--- I t G VI V2 V 3 C V1 V 2 V 3

Fig 10 Effects of light intensity reduction on Fig 11 Effects of reducing light intensity on the length of stem, number of leaves and height _{the weight}_of_{whole plant}_of_{new corms} of plant in blind plant in gladiolus C: no shad-

ing (control), V1, V2, V3: shaded by one, two and threefold victoria lawn

-natural day length short (8 hour) day length

Table 30 -Effects of light intensity reduction on the flowering in gladiolus during summer season

Average date Number of Percentage Height of Number of of flowering florets Of flowering plant

1

leaves

*

N: natural day length, S: short day (8 hours), V1, V2, V3: shaded by one, two and threefold victoria lawn. 85 3% 0 0 0 4 6

-

-.

-

1 0

-

- 40

1

Oct 14

:zt

1

40

-

40

1 -

N-V3 40

1

- S-Cont S-V I S-V2 S-V3 1 1 6 3 C m

-

8 2 - - - 0 - 0 O / -40 40 40 40 9 0 -- --

-

Oct. 17

-

(33)

Studies on production and flowering in gladiolus 3 1

plots were lighted with 100 W incandescent lamps from October 1 to prevent short day effect.

Results

The results obtained are shown in tables 30 and 31, figs. 10 and 11.

Table 30 shows that none of the plants bloomed, except 85.3% flowering in natural day-length check plot and 3.1 % in short day check plot.

Fig. 10 shows that the length of stem and the number of leaves were decreased when the light intensity was reduced, but a tendency of etiolation was observed in one and two fold victoria lawn plots, and the weakest growth was observed in the three fold plot.

Fig. 11 shows that the weight of whole plant and that of new corms were de.. creased when the light intensity was reduced, except the new corms in natural day-length check plot.

In general, the-length of stem, number of leaves, height of plant, weight of whole plant and weight of new corms in short day plots were smaller and less than those of natural day-length.

Table 31 shows the mean temperature and mean maximum light intensity in the plot during the course of the experiment.

From these results, it seems that high night temperature after low light intensity increases the amount of blindness as Post and Runger pointed out.

Table 31 -Mean temperature and mean maximum light intensity in the plot during the experiment

JI.

Nutrition and water 1. Effect of nutritional treatments .-

Temperature Maximum

1

Minimum

(I). Effect of nutritional treatments

*

As per cent of N-control plot intensity

**

As per cent of out-door intensity (77,600 lux)

Light intensity Maximum

I

Percent

1

63,800luX

/

100*(822**)% 27,006 I 43 (35. 3) 12,310 19 (15 6) 5,840 Experiment 24(26)

(Experiment of May to November, 1958.)

215" 18 1 19 6 19 4 21 4 20 8 21 1 20.9 N-Cont. N-V 1 N-V2 N-V3 S-Cont S-Vl S-V2 S-V3 62,600 31,400 14,360 6,960 31.0" 30 8 29.3 29. 4 32 9 32 3 31 2 31.0 98 (80 6 ) 49 (40 3) 23 (18 9) 11 ( 9.0)

(34)

Kiyoshi KOSUGI

/

According to the design shown in table 32, corms of Spotlight variety (average weight 25.78) were planted in sand in Wagner's pots three corms per pot, on May 26, 1958 and nutritional treatments were made from June 17 to September 1 3 a t 3 day intervals during the course of experiments.

Table 32 -Design of fertilizer treatment

-- --

1

Rate of

1

Amount of

Samplings for chemical analysis were made a t the time of flowering, August 21, and a t the time of digging, November 5, 1958.. T h e date of flowering, height of plants, number of leaves and number of florets were recorded a t the flowering time. Fresh weight of tops, new corms, and cormels, and number of cormels were measured a t the digging time,

Analytical methods employed were Kjeldahl method for nitrogen, ammonium molybudate and colorirneter for phosphorus, and flame photometer for potassium..

(35)

Results The results obtained are shown in figs. 12,-17.

L S D . N S Average d a t e of flowering 5% 3 0 L S.D. ''11% 4 1

A d ' -

-

K 2 K 1 K 2 K 1 K 2 K 1 P 2 P

Fig 12 Effects of nutritional treatments on the average date of flowering and percentage of flowering

From fig. 12 no significant difference was observed in the percentage of flowering, and earlier flowering was observed in the plots treated with 200, 100 ppm N and 50 ppm P, but later flowering was observed in - N plots.

l l O C d _{Fresh weight of t o p} L > V '-11%45

v%

4

-r s n ~ = 1 % 3 8

20t -v w 8 0

Fresh weight of new corm

Number o f leaves L S D N S

Number of florets LS.D N S A

A.

-

.I\.

2%

.A

/*

&A/

Fig 13 Effects of nutritional treatments on the height of plant, number of leaves, number of florets, fresh weight of top and fresh weight of new corm

From fig.. 13, no significant differences were observed in the height of plant, number of leaves and number of florets, although there were a few blind stalks in

(36)

34 Kiyoshi KOSUGI

-,N and several in other plots, and fresh weight of tops and new corms were increas. ed with increasing nitrogen.

In general, the color of leaves in the plots supplied with 50 ppm N or --,N was yellowish-green, which is clearly the nitrogen deficient symptom, and these plants showed weaker growth. In the plants of 200 ppm N, the color of leaves was dark green and the plants looked vigorous, but the color of roots was dark brown and the development of root system was poor.

4 3

1

Number of cormels 1 20

-

10 -- 9

-

8 - 7

-

6

-

5

-

4

-

3

-

Fresh weight of cormel

a,h f i - h - a t . M A-

*

Ap

8%

L I - N P K N K N K N N N

O d ; ; i i i i z

1 2 4 1 2 1 2 4 1 2

i b d

ii4

; i d

i h h

ii4

; 2 4 N N N 1 P 2 P 1 K 2 K 1 K 2 K 1 K 2 K 1 P 2 P

Fig 14 Effects of nutritional treatments on the number of cormels and fresh weight of cormel

-

A t the timP of flowering

&-A A t the time of digging

Fig. 15. Effects of nutritional treatments on the contents of nitrogen, phosphorus and potassium in the top.

(37)

Studies on production and flowering in gladiolus 3 5

From fig. 1 4 it is seen that the number of cormels increased in the. plots supplied with low level nitrogen, and decreased remarkably in 200 ppm N plots, and there was no significant difference in the fresh weight of cormels.

% 2

N l ~ k a . ~ i J ~ i ~

a!

_d

P

A-A A'

/kAeA

0 1 \,pa %-A A 7 3 4

Fig 16. Eff'ects of nutritional treatments on the contents of nitrogen, phosphorus and potassium in new corm

I I I I L 1 " " I I l l I l l 1 1 1 1 L

1 2 4 1 2 1 2 4 1 2 4 1 2 4 1 2 4 1 2 4 1 2 4

N K N N N N N N

2 P 1 K Z K 1 7 2P K 1 K 2 K

2 P

Fig 17 Effects of nutritional treatments on the amounts of nitrogen, phosphorus and potassium absorbed by gladiolus

Figs. 15, 16 and 17 show that; absorption of nitrogen increased with increasing of nitrogen supply regardless of application rates of phosphorus or potassium. With increasing phosphorus supply, increased not only P absorption but also N absorption, except the plot supplied with phosphorus alone. With increasing potassium supply increased K absorption slightly when it was supplied with 25, 50 ppm P or 100 ppm N, and decreased when it was supplied with 200 ppm N.

(38)

Kiyoshi KOSUGI

From the results mentioned above, it seems that nitrogen is related strongly to flowering in gladiolus, and the optimum nitrogen concentration for flowering is 100 ppm. And phosphorus promotes the effect of nitrogen.

(2). Effect of nutritional treatments of the previous year Experiment 25(27)

(Experiment of March to July, 1959.) Materials and methods

Table 33. -Effects of nutritional treatments on the contents of nitrogen, phosphorus and potassium in the corm of gladiolus

(Var Spotlight)

-

Treatment in previous Nutritional content in corm

( % in d r y matter) Number of Average Plot

1

year --

I

corms

I

weight of

planted corm

(39)

Corms of Spotlight variety which were shown in table 33 were planted in the bench with sand in the experimental greenhouse a t Kagawa University on March 19, 1959, and they were grown with water alone (no fertilizer was added).

The number of germinated corms, date of flowering, number of plants died, number of blind plants, and number of flowered plants were recorded. On July 31, all plants were dug up, and the fresh weight of tops, fresh weight of corms, and number of cormels were recorded.

Cormels of the same variety which were shown in table 35 were planted in the same greenhouse on March 20, and they were dug up on June 4, and the fresh

Table 34 -Effects of nutritional treatments in the previous year, on the percentage of

germinated corm, percentage of dead plant, percentage of blind plant, length of stalk with blind flower, and percentage of flowering in the year

*

less than 0.1 cm. Percentage of blind plant Plot Per centage of r K - g e r m i n a t e d Treatment in previous year

1

Percentage of dead plant Length of stalk with blind flower Percentage flowering

(40)

38 Kiyoshi Kosucr

weight of the plants were measured.

Results

The results obtained are shown in tables 34, 35, figs. 18, 19, 20 and 21.

Table 34 shows the percentage of germination and percentage of flowering were high in the plants to which nitrogen was applied in the previous year, and the percentage of plants died and percentage of blind stalks were high in -N plots. Several malformed plants were observed in the plot in which 200 ppm N alone was applied. In fig. 18 earlier flowering is observed in the plants to which 100 ppm N and 25, 50 ppm P were applied in the previous year, and later flowering in -- N plots or the plots to which 200 ppm N alone was applied.

L

Fig 18 Effects of nutritional treatments in the previous year on the date of flowering in the current year

In fig. 19, no difference was observed in the number of leaves between the plants to which nitrogen was applied but not in the previous year, nevertheless, the number of florets was increased in the plants to which nitrogen was applied in the previous year.

Number

o f

leaves

2 ' " 1 " " " " ' " " ' " ' " ' ' " " 1 1 " ' I ' $ 1 2 4 7 2 1 2 1 2 4 1 2 1 2 4 1 2 1 2 4 I 2 4 1 2 4 1 2 1 1 2 4 1 2 4 N N P K N K N K N N N T 1 P 2 P l K 2 K l K 2N K 1N K 2N K

!

1 P 2 P L

Fig 19 Effects of nutritional treatments in the previous year on the number of leaves and number of florets in the current year