BIOLOGY AND MANAGEMENT OF FIMBRISTYLIS MILIACEA (L.) VAHL
By
MAHFUZA BEGUM
Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia,
in Fulfillment of the Requirement for the Degree of Doctor of Philosophy
September 2006
ii
Dedicated
To
My Father, Memory of My Mother and Niece Moonmoon
And
My Husband Md. Zahid Iqbal, Kids Promee and Alvee,
with Whom I experience the Joys and
Responsibilities of Commitment Each Day
iii
Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment
of the requirement for the degree of Doctor of Philosophy
BIOLOGY AND MANAGEMENT OF FIMBRISTYLIS MILIACEA (L.) VAHL
By
MAHFUZA BEGUM
September 2006
Chairman: Associate Professor Abdul Shukor Juraimi, PhD
Faculty: Agriculture
Most experiments were carried out in a glasshouse at Universiti Putra Malaysia,
while the field survey was conducted in ricefields in the Muda area, Kedah. This
study was initiated during March 2003 and ended on November 2005. The objectives
of the study were to investigate the prevalence of F. miliacea in ricefields both above
ground as well as in the soil seedbank, its emergence behaviour, life cycle, life table,
competitive ability with rice, and its management.
Results from field survey revealed that F. miliacea was the fifth most prevalent
weed out of 35 species in the Muda area with 46 -52% fields infested and widely
distributed over the four districts of Muda with infestation rating scores from traces –
30% weed coverage. Out of 20 weed species identified in the soil seedbank, F.
miliacea was the most abundant with 66.07% of total seed reserve (equivalent to
750.84 million seeds/ha), of which 55% emerged in soils incubated in trays (411.48
million seedlings/ha), 8% germinated in incubation tests in petridishes (61.59 million
seedlings/ha), while 37% or the equivalent of 277.77 million seeds/ha remained
dormant or dead.
iv
Fimbristylis miliacea exhibited high emergence (44.38%) from surface seeding.
Seeds sown at 0.5 cm depth had significantly reduced emergence (13%) and no
seedlings emerged from 1.0 cm soil depth. For flooding durations of 7, 14 and 21
days, per cent emergence and dry matter production were higher under saturated
conditions than at 5 and 10 cm flooding depths. A flooding duration of 14 days or
more and in flooding depth up to 10 cm showed a clear trend in reduced emergence
and dry matter production of Fimbristylis miliacea.
During the cropping season (4 month period) each F. miliacea plant produced on
average of 2.3 tillers/plant and a total of 134 inflorescences, with 84
inflorescences/plant ripening within this period. Each inflorescence comprised of 48
spikelets with 511 seeds and matured after 3 weeks of emergence. Total seeds/plant
and 1000 seed weight were 42,275 and 0.035 g, respectively. Time required for seed
ripening was 76 days after emergence. This species had three important growth
stages: a slow growth stage during the first 4 week after emergence (WAE); a rapid
growth stage from 4-9 WAE; and finally, a maximum growth stage from 9-17 WAE.
The life table study showed that plants establishing from every 100 seeds of F.
miliacea plants can reproduce 287,722 seeds with nitrogen treatment, which was
1.66 fold greater than without nitrogen. High death rates in F. miliacea among young
seedlings indicated a Deevey Type III survivorship curve. Early emerging cohorts
had greater survivorship and contributed most extensively to the next generation by
producing more than 90% seeds.
The interaction between weed density and nitrogen (N) fertilization had a
pronounced influence on rice yield. At low weed densities of up to 500 plants/m2,
v
rice yields increased with higher N fertilization. On the other hand, at the higher
weed density of 1000 plants/m2, increasing N fertilization to 170 kg/ha had no
significant effect on yield. However, rice yield at this level of N fertilization with the
lowest weed density of 250 plants/m2, was similar to the weed-free treatment. Based
on the predicted Logistic and Gompertz response curves the critical period for
controlling F. miliacea in direct-seeded rice was between 14 – 28 days after sowing.
Flooding and use of herbicides are two important weed control methods in direct-
seeded rice. Flooding had a major suppressive effect on stand establishment and
growth of F. miliacea, especially during the early growth stages (7 and 14 DAS).
Delayed flooding at 21 and 28 DAS required a 10 cm flooding depth for effective
control. All tested herbicides were effective in controlling F. miliacea, but the
herbicides bensulfuron and fentrazamide increased grain yield by more than 80%
compared to the unweeded treatment and were comparable to the weed-free (hand-
weeded) treatment.
vi
Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai
memenuhi keperluan untuk ijazah Doktor Falsafah
BIOLOGI DAN PENGURUSAN FIMBRISTYLIS MILIACEA (L.) VAHL
Oleh
MAHFUZA BEGUM
September 2006
Pengerusi: Profesor Madya Abdul Shukor Juraimi, PhD
Fakulti: Pertanian
Sebahagian besar eksperimen telah dijalankan di rumah kaca, Universiti Putra
Malaysia, sementara survei rumpai dijalankan di kawasan jelapang padi, Muda,
Kedah. Kajian bermula pada bulan Mac 2003 dan berakhir pada bulan November
2005. Objektif kajian ialah untuk menentukan tahap dominan Fimbristylis miliacea
di kawasan Muda di samping menentukan tahap bank benihnya dalam tanah, tabiat
kemunculannya, kitar hidup, jadual hayat, keupayaan daya saing dengan tanaman
padi, dan juga pengurusannya.
Keputusan survei mendapati F. miliacea adalah rumpai yang ke lima terbanyak
daripada 35 spesies yang direkodkan di kawasan Muda dengan 46-52% kawasan
didapati diinfestasi, dan mempunyai taburan meluas meliputi empat daerah di Muda
dengan skor infestasi bermula dengan sangat sedikit (beberapa pokok) sehingga 30%
litupan. Daripada 20 spesies rumpai yang dikenalpasti daripada bank biji benih
dalam tanah, F. miliacea adalah yang paling banyak iaitu 66.07% (750.84 juta biji
benih/ha) daripada keseluruhan yang tersimpan, dengan 55% (411.48 juta anak
benih/ha) muncul ketika ujian dalam kotak percambahan, 8% (61.59 juta anak
vii
benih/ha) bercambah dalam piring petri dan 37% (277.77 juta biji benih/ha) dorman
atau mati.
F. miliacea menunjukkan kemunculan yang tinggi (44.38%) daripada rawatan
penanaman di permukaan. Kemunculan biji benih yang ditabur pada kedalaman 0.5
cm menurun dengan bererti kepada 13% dan tiada benih muncul pada kedalaman
tanah 1.0 cm. Untuk tempoh pembanjiran 7, 14 dan 21 hari, peratus kemunculan dan
berat kering adalah tinggi pada kedaan tanah tepu air berbanding dalam kedaan air
bertakung sedalam 5 dan 10 cm. Pembanjiran selama 14 hari atau lebih dan
kedalaman pembanjiran sehingga 10 cm menunjukkan polar penurunan kemunculan
dan penghasilan berat kering F. miliacea.
Ketika musim penanaman padi (tempoh 4 bulan) setiap pohon F. miliacea
menghasilkan purata 2.3 anak bilah/pokok dan 134 infloresen, dengan 84
infloresen/pokok yang matang semasa tempoh tersebut. setiap infloresen
mengandungi 48 spika dengan 511 biji benih dan matang 3 minggu selepas muncul.
Jumlah bilangan biji benih/pokok dan berat 1000 biji benih adalah masing-masing
42275 biji dan 0.035 g. Masa yang diperlukan untuk benih masak adalah 76 hari
selepas muncul. Spesies ini mempunyai tiga peringkat pertumbuhan : peringkat
pertumbuhan lambat, 4 minggu pertama selepas muncul (MSM); peringkat
pertumbuhan cepat, 4-9 MSM; dan peringkat pertumbuhan maksimum, 9-17 MSM.
Jadual hayat menunjukkan pokok yang tumbuh daripada setiap 100 biji benih boleh
menghasilkan 287,722 biji dengan penambahan nitrogen, 1.66 kali ganda lebih
daripada tanpa nitrogen. Kadar kematian yang tinggi dikalangan anak benih F.
miliacea menandakan kemandirian kelok “Deevey Type III”. Kohort yang muncul
viii
awal mempunyai peluang hidup yang besar dengan menghasilkan 90% benih untuk
generasi seterusnya.
Interaksi antara kepadatan rumpai dan pembajaan N mempunyai pengaruh yang kuat
terhadap hasil padi. Pada kepadatan rendah sehingga 500 pokok/m2, hasil padi
bertambah dengan pembajaan N. Sebaliknya pada kepadatan tinggi 1000 pokok/m2,
penambahan pembajaan N sehingga 170 kg/ha tidak menunjukkan kesan bermanfaat
terhadap hasil padi. Walau bagaimanapun pada paras pembajaan N ini, hasil padi
pada kepadatan rumpai yang terendah 250 pokok/m2, adalah sama dengan rawatan
bebas rumpai. Berdasarkan peramalan kelok rangsang Logistic dan Gompertz,
tempoh kritikal untuk kawalan F. miliacea adalah antara 14 – 28 hari lepas tabur.
Pembanjiran dan penggunaan racun herba adalah dua keadah penting kawalan
penting di kawasan tanaman padi tabur terus. Pembanjiran menunjukkan kesan
kawalan yang kuat terhadap penapakan dan pertumbuhan F. miliacea, terutamanya
ketika peringkat awal tanaman [(7 dan 14 hari lepas tanam (HLT)]. Menangguhkan
rawatan pembanjiran kepada 21 dan 28 HLT memerlukan 10 cm kedalaman air
untuk kawalan yang berkesan. Semua racun rumpai diguna dapat mengawal F.
miliacea dengan berkesan, tetapi rawatan bensulfuron dan fentrazamide dapat
meningkatkan hasil padi melebehi 80% berbanding rawatan tanpa kawalan rumpai,
dan setara dengan rawatan bebas daripada rumpai.
ix
ACKNOWLEDGEMENTS
Praise to Almighty Allah for His blessings, kindness and giving me proper guidance,
strength, and will to complete this study.
I wish to express my heartfelt gratitude, indebtedness, and deep sense of respect to
Dr. Abdul Shukor Juraimi, the Chairman of the Supervisory Committee for his
sincere support, guidance, constant encouragement, invaluable suggestions and
generous help throughout the study period. I am much indebted and grateful to
Associate Professor Dr. Rajan Amartalingam, Associate Professor Dr. Syed Omar
Bin Syed Rastan, and Dr. Azmi Bin Man, members of the supervisory committee, for
their encouragement, constructive suggestions and guidance in formulation and
execution of the research projects and critical review of the manuscript.
I, thankfully acknowledge the assistance of TWOWS (Third World Organization for
Women in Science) for financial support and facilitating my study in Malaysia, and
Universiti Putra Malaysia for providing research facilities under the Intensification of
Research priority Areas No. 01-02-04-0778-PR0068/05-05. Furthermore, I am
grateful to the administrative authority of Bangladesh Agricultural University (BAU)
for providing deputation and all kinds of help to accomplish my degree.
I feel proud to express my sincere appreciation and indebtedness to all of my
teachers of the Department of Agronomy, BAU, for their cooperation,
encouragement and valuable suggestions. I would like to thank Hj Yasir Isman for
his assistance in glasshouse and field works. I also wish to express my appreciation
to all of my post graduate friends and well wishers.
x
I respectfully acknowledge the blessings and good wishes of my father, sisters,
brothers, brother-in-law, sister-in-law and relatives. I am especially grateful to my
sister Dr. Salina Begum and mother-in-law, who, despite their heavy professional
commitment and old age had provided lots of encouragement and moral support and
looked after my children in my absence. Special gratitude must go to my daughter
Sadia Nowrin Promee and son Iqbal Maheer Alvee who have faced difficult times
during my study period. Without their love, great sacrifice, and support this study
would not have been possible.
Finally, and above all my husband Md Zahid Iqbal deserves a lot of thanks and
appreciation not only for his love and care, but also for bearing the burden and
responsibilities of taking care of our children in my absence, in addition, later on, for
active cooperation and support to conduct experiments and encouragement a higher
degree.
I would like to express my humble apology to those persons, who helped me but may
not find their names in my narration here.
xi
I certify that an Examination Committee has met on 18 September 2006 to conduct
the final examination of Mahfuza Begum on her Doctor of Philosophy thesis entitled
“Biology and Management of Fimbristylis miliacea (L.) Vahl” in accordance with
Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian
Malaysia (Higher Degree) Regulations 1981. The Committee recommends that the
candidate be awarded the relevant degree. Members of the Examination Committee
are as follows:
Mohd Razi Ismail, PhD
Professor
Faculty of Agriculture
Universiti Putra Malaysia
(Chairman)
Rosli Mohamad, PhD Professor
Faculty of Agriculture
Universiti Putra Malaysia
(Internal Examiner)
Anuar Abdul Rahim, PhD
Associate Professor
Faculty of Agriculture
Universiti Putra Malaysia
(Internal Examiner)
Mahsor Mansor, PhD
Professor
School of Biological Sciences
Universiti Sains Malaysia
(External Examiner)
________________________________
HASANAH MOHD GHAZALI, PhD
Professor/Deputy Dean
School of Graduate Studies
Universiti Putra Malaysia
Date:
xii
This thesis submitted to the Senate of Universiti Putra Malaysia and has been
accepted as fulfilment of the requirement for the degree of Doctor of Philosophy.
The members of the Supervisory Committee are as follows:
Abdul Shukor Juraimi, PhD
Associate Professor
Faculty of Agriculture
Universiti Putra Malaysia
(Chairman)
Rajan Amartalingam, PhD
Associate Professor
Faculty of Agriculture
Universiti Putra Malaysia
(Member)
Syed Omar Syed Rastan, PhD
Associate Professor
Faculty of Agriculture
Universiti Putra Malaysia
(Member)
Azmi Man, PhD
MARDI
Kepala Batas, Pulau Pinang
(Member)
_______________________
AINI IDERIS, PhD
Professor/Deputy Dean
School of Graduate Studies
Universiti Putra Malaysia
Date:
xiii
DECLARATION
I hereby declare that the thesis is based on my original work except for quotations
and citations which have been duly acknowledged. I also declare it has not been
previously or concurrently submitted for any other degree at UPM or other
institutions.
____________________
MAHFUZA BEGUM
Date: 18 October 2006
xiv
TABLE OF CONTENTS
Page
DEDICATION ii
ABSTRACT iii
ABSTRAK vi
ACKNOWLEDGEMENTS ix
APPROVAL xi
DECLARATION xiii
LIST OF TABLES xvii
LIST OF FIGURES xix
CHAPTER
1 INTRODUCTION
1.1
2 LITERATURE REVIEW 2.1
2.1 Fimbristylis miliacea (L.) Vahl 2.1
2.1.1 Introduction 2.1
2.1.2 Geographical Distribution 2.2
2.1.3 Taxonomic Description 2.3
2.1.4 Morphology 2.4
2.1.5 Physiology 2.5
2.1.6 Reproduction 2.5
2.1.7 Ecological Habitat 2.6
2.1.8 Agricultural and Economic Importance 2.6
2.2 Ecology of Weeds in Ricefields 2.7
2.2.1 Weed Communities 2.7
2.2.2 Shift in Weed Species Composition 2.9
2.2.3 Status of F. miliacea in Ricefields 2.10
2.3 Soil Seedbank 2.14
2.3.1 Number of Seeds in the Seedbank 2.14
2.3.2 Species Composition in the Seedbank 2.15
2.3.3 Fate of Seeds in the Seedbank 2.16
2.3.4 Emergence Patterns 2.17
2.3.5 Prediction of Potential Above-ground Weed
flora
2.18
2.4 Weed Seedling Emergence 2.19
2.4.1 Soil Depth and Seedling Emergence 2.19
2.4.2 Flooding and Seedling Emergence 2.21
2.5 Life Cycle of Weeds 2.22
2.6 Life Table of Weeds 2.24
2.6.1 Emergence Cohort 2.24
2.6.2 Weed Survivorship 2.25
2.6.3 Reproductive Capacity of Weeds 2.26
2.7 Weed-Crop Competition 2.28
2.7.1 Competition 2.28
2.7.2 Weed-Crop Density 2.29
xv
2.7.3 Effect of Nitrogen on Competition 2.30
2.8 Critical Period for Competition 2.32
2.9 Management of F. miliacea in Ricefields 2.35
2.9.1 Management by Flooding 2.35
2.9.2 Management by Herbicides 2.37
3 OCCURRENCE OF Fimbristylis miliacea (L.) Vahl IN
MUDA RICEFIELD AREA
3.1
3.1 SURVEY ON WEEDS OF RICE FIELDS IN MUDA
AREA
3.1
3.1.1 INTRODUCTION 3.1
3.1.2 MATERIALS AND METHODS 3.3
3.1.3 RESULTS AND DISCUSSION 3.5
3.1.4 CONCLUSION 3.15
3.2 SEEDBANK STUDY ON RICEFIELD SOILS FROM
THE MUDA AREA
3.16
3.2.1 INTRODUCTION 3.16
3.2.2 MATERIALS AND METHODS 3.19
3.2.3 RESULTS AND DISCUSSION 3.21
3.2.4 CONCLUSION
3.32
4 EMERGENCE CHARACTERISTICS OF Fimbristylis
miliacea (L.) Vahl
4.1
4.1 SOWING DEPTH ON SEEDLING EMERGENCE 4.1
4.1.1 INTRODUCTION 4.1
4.1.2 MATERIALS AND METHODS 4.1
4.1.3 RESULTS AND DISCUSSION 4.2
4.1.4 CONCLUSION 4.3
4.2 FLOODING DEPTH AND DURATION ON
SEEDLING EMERGENCE
4.4
4.2.1 INTRODUCTION 4.4
4.2.2 MATERIALS AND METHODS 4.5
4.2.3 RESULTS AND DISCUSSION 4.6
4.2.4 CONCLUSION 4.9
5 LIFE CYCLE AND LIFE TABLE STUDY OF
Fimbristylis miliacea (L.) Vahl
5.1
5.1 LIFE CYCLE STUDY 5.1
5.1.1 INTRODUCTION 5.1
5.1.2 MATERIALS AND METHODS 5.3
5.1.3 RESULTS AND DISCUSSION 5.5
5.1.4 CONCLUSION 5.11
5.2 LIFE TABLE STUDY 5.12
5.2.1 INTRODUCTION 5.12
5.2.2 MATERIALS AND METHODS 5.15
5.2.3 RESULTS AND DISCUSSION 5.16
5.2.4 CONCLUSION
5.23
xvi
6 COMPETITION STUDIES BETWEEN RICE AND
Fimbristylis miliacea (L.) Vahl
6.1
6.1 COMPETITION IN RELATION TO NITROGEN
LEVELS AND WEED DENSITY
6.1
6.1.1 INTRODUCTION 6.1
6.1.2 MATERIALS AND METHODS 6.3
6.1.3 RESULTS AND DISCUSSION 6.5
6.1.4 CONCLUSION 6.12
6.2 CRITICAL PERIOD OF COMPETITION 6.12
6.2.1 INTRODUCTION 6.12
6.2.2 MATERIALS AND METHODS 6.15
6.2.3 RESULTS AND DISCUSSION 6.18
6.2.4 CONCLUSION
6.24
7 CULTURAL AND CHEMICAL CONTROL OF
Fimbristylis miliacea (L.) Vahl
7.1
7.1 TIME AND DEPTH OF FLOODING ON SURVIVAL
AND GROWTH OF Fimbristylis miliacea
7.1
7.1.1 INTRODUCTION 7.1
7.1.2 MATERIALS AND METHODS 7.2
7.1.3 RESULTS AND DISCUSSION 7.3
7.1.4 CONCLUSION 7.5
7.2 EFFICACY OF SELECTED HERBICIDES FOR
THE CONTROL OF Fimbristylis miliacea
7.6
7.2.1 INTRODUCTION 7.6
7.2.2 MATERIALS AND METHODS 7.8
7.2.3 RESULTS AND DISCUSSION 7.10
7.2.4 CONCLUSION
7.18
8 GENERAL CONCLUSIONS, RECOMMENDATIONS
AND SUGGESTIONS FOR FUTURE RESEARCH
8.1
8.1 GENERAL CONCLUSIONS 8.1
8.2 RECOMMENDATIONS 8.4
8.3 SUGGESTIONS FOR FUTURE RESEARCH 8.5
REFERENCES R.1
APPENDICES A.1
BIODATA OF THE AUTHOR B.1
xvii
LIST OF TABLES
Table Page
3.1 The number of weed species observed within the blocks in the
Muda area
3.34
3.2 Distribution of weed species based on family affiliation and weed
type in the four districts of Muda rice granary area
3.35
3.3 Occurrence of weed species in the 4 districts of Muda rice granary
area (% of fields infested)
3.36
3.4 Sorenson’s index of similarity in weed species among the four
districts in the Muda rice granary area
3.36
3.5 The occurrence at six levels of frequency for 8 or 9 most abundant
weed species in direct-seeded rice in the four districts in Muda
area
3.37
3.6 Occurrence of weed species based on per cent-infested fields out
of 579 fields surveyed in Muda rice granary
3.38
3.7 Number of ricefields infested by each species at each of six levels
of occurrence (Total fields surveyed = 579)
3.39
3.8 Total seedling emergence of 14 common weed species in soils
from Muda ricefields
3.40
3.9 Total number of ungerminated seed reserves of 13 common weed
species in soils from Muda ricefields after the 12 month incubation
period
3.41
3.10 Mean weed seedbank of 20 taxa in ricefield soils in Muda area
3.42
3.11 Frequency of occurrence of individual weed species in the soil
seedbank
3.42
3.12 Total emerged seedlings, ungerminated seeds and total seed
reserves of F. miliacea at 24 sampling sites
3.43
4.1 Emergence percentage of F. miliacea at different depths and
duration of flooding
4.10
5.1 Growth pattern of F. miliacea plant during the 4 month period
after sowing
5.25
5.2 Approximate time required for seedling emergence, leaf, tiller and
inflorescence formation and inflorescence ripening
5.26
xviii
5.3 Influence of nitrogen fertilizer on % emergence and
seeds/inflorescence (Average value of 4 cohorts)
5.27
5.4 Differences between cohorts on % emergence and
seeds/inflorescence (Average value of 4 cohorts)
5.27
5.5 Effect of nitrogen fertilizer on % emergence, % survival, total
tillers, inflorescence/pot, seeds/pot and dry matter/pot of F.
miliacea (Cumulative value of 4 cohorts)
5.27
6.1 Vegetative growth and yield contributing characters influenced by
weed density
6.25
6.2 Vegetative growth and yield contributing characters influenced by
N levels
6.25
6.3 Plant height and yield components of rice as affected by different
periods of F. miliacea competition
6.26
6.4 Rice straw biomass, weed dry matter, grain yield and % grain
yield loss as affected by different period of F. miliacea
competition
6.27
6.5 Maximum weed-interference and minimum weed-free period in
rice calculated from regression equation for three predetermined
levels of crop yield loss
6.27
7.1 Herbicide treatments used to control of Fimbristylis miliacea 7.20
7.2 Effect of herbicides on weed control, crop toxicity rating at 21
DAA, chlorophyll content at panicle initiation and rice plant
height at harvest
7.20
7.3 Yield contributing characters of rice as affected by weed control
treatment
7.21
7.4 Production of straw and grain yield due to weed control treatments 7.21
xix
LIST OF FIGURES
Figure Page
2.1 Fimbristylis miliacea (L.) Vahl. a spikelet; b. glume, dorsal view
(opened); c. flower; d. nut (Adopted from Soerjani et al., 1987)
2.45
2.2 Ricefield infested by F. miliacea (L.) Vahl in Muda area
2.46
2.3 The seed bank cycle (inputs to the seed bank are shown with black
arrows and losses in white arrows, modified from Anil Shrestha,
2001)
2.46
2.4 Scheme illustrating the life cycle of an annual flowering plant,
adopted from Grim (1979)
2.47
3.1 The Four Districts in the Muda area in Peninsular Malaysia where
the survey was conducted
3.44
3.2 Weed communities in different districts of Muda rice granary area
3.45
3.3 Weed distribution by communities in the Muda rice granary area
3.45
3.4 Severity of F. miliacea infestation in five farm blocks in District-I
3.46
3.5 Severity of F. miliacea infestation in nine farm blocks in District-
II
3.46
3.6 Severity of F. miliacea infestation in six farm blocks in District-III
3.47
3.7 Severity of F. miliacea infestation in seven farm blocks in
District- IV
3.47
3.8 Soil sampling sites in the Muda area in Peninsular Malaysia
3.48
3.9 Number of germinable seeds, remaining seeds and total seed
reserve in soil samples from all sites in Muda ricefields (AB- Alor
Belat; BT- Batu-17; SD - Sungai Daun; ST - Simpang Tiga)
3.49
3.10 Total number of seedlings and remaining seeds as a percentage of
the total seeds in the top 10 cm of soil in Muda ricefields (AB –
Alor Belat; BT – Batu-17; SD – Sungai Daun; ST – Simpan Tiga)
3.50
3.11 Relative proportion of germinable seeds of five most important
weed species in the soil seedbank of Muda ricefields
3.51
3.12 Relative proportion of ungerminated seed reserves of five most
important weed species in the soil seedbank in Muda ricefields
3.51
xx
3.13 Relative proportion of total soil seedbank of five most important
weed species in Muda ricefields
3.51
3.14 Periodic and cumulative weed seedling emergence in Muda
ricefield soils during the12 month period
3.52
3.15 Number of weed seedlings emergence in soil samples from all
sites in Muda ricefields (AB- Alor Belat; BT- Batu-17; SD -
Sungai Daun; ST - Simpang Tiga)
3.53
3.16 Temporal variation in F. miliacea seedling emergence relative to
other species during the 12 month incubation of the soil samples
from Muda ricefields (mean of all locations)
3.54
3.17 Cumulative emergence of F. miliacea seedlings relative to other
species during the 12 month incubation of the soil samples from
Muda ricefields (mean of all locations)
3.54
3.18 Mean number and percentage F. miliacea seedbank in Muda area.
3.55
4.1 Effect of sowing depth on cumulative emergence of F. miliacea
after 7, 14, 21 and 28 days of sowing (Error bar denotes ± SE)
4.10
4.2 Effect of flooding depth and duration on dry matter of F. miliacea
(Means within flooding durations with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
4.11
5.1 Weekly measured plant height and inflorescence number of F.
miliacea (Means within week after emergence (WAE) with same
alphabets are not significantly different at P ≥ 0.05 (Tukeys Test))
5.28
5.2 Relationship between tiller number and inflorescence number
5.28
5.3 Life cycle of Fimbristylis miliacea (L.) Vahl
5.29
5.4 Survivorship curves of F. miliacea (Means within cohorts with
same alphabets are not significantly different at P ≥ 0.05 (Tukeys
Test)
5.30
5.5 Cohorts’ survivorship curves of F. miliacea (with nitrogen
application)
5.30
5.6 Cohorts’ survivorship curves of F. miliacea (without nitrogen
application)
5.31
5.7 Fecundity (Inflorescences/plant) of successive plants of F.
miliacea over a four month period (Means within cohorts with
same alphabets are not significantly different at P ≥ 0.05 (Tukeys
Test))
5.31
xxi
5.8 Fecundity (seeds/plant) of successive plants of F. miliacea over a
four month periods (Means within cohorts with same alphabets are
not significantly different at P ≥ 0.05 (Tukeys Test))
5.32
5.9 Contribution of successive cohorts of F. miliacea to total seed
production (With nitrogen application)
5.32
5.10 Contribution of successive cohorts of F. miliacea to total seed
production (Without nitrogen application)
5.33
5.11 Fecundity (seeds/pot) of successive plants of F. miliacea over a
four month period (Means within cohorts with same alphabets are
not significantly different at P ≥ 0.05 (Tukeys Test))
5.33
5.12 The flow chart of life table of F. miliacea which was treated with
nitrogen 100 kg / ha (A) and without nitrogen (B)
5.34
6.1 Rice plant height response to N treatment for all weed density
levels (Means within N levels with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
6.28
6.2 Rice straw biomass in response to N treatment for all weed density
levels (Means within N levels with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
6.28
6.3 Weed dry matter content in response to N treatment for all weed
density levels (Means within N levels with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
6.29
6.4 Nitrogen uptake by the weed in response to N treatment for all
weed density levels (Means within N levels with same alphabets
are not significantly different at P ≥ 0.05 (Tukeys Test))
6.29
6.5 Rice productive tillers variation to N treatment for all weed
density levels (Means within N levels with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
6.30
6.6 Grains/panicle variation to N treatment for all weed density levels
(Means within N levels with same alphabets are not significantly
different at P ≥ 0.05 (Tukeys Test))
6.30
6.7 Grain yield variation due to N treatment for all weed density
levels (Means within N levels with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
6.31
6.8 Regression of grain yield on weed dry matter at 100 kg/ha N level
6.31
6.9 Regression of grain yield on weed dry matter at 170 kg/ha N level
6.32
xxii
6.10 Treatments tested for critical period of competition between rice
and Fimbristylis miliacea
6.32
6.11 Regression of grain yield on weed dry matter
6.33
6.12 Effect of different periods of weed competition on rice grain
yields. Gompertz equation RY = -162.3648 + 258.6611* exp(-
exp(x -15.1943)/8.1087)), R2 = 0.97; Logistic equation RY =
51.8034 + 47.5228/ (1+ (x/45.8380) 1.9916
, R2 = 0.99
6.33
7.1 Effect of time and depth of flooding on survival of F. miliacea
(Means within columns with same alphabets are not significantly
different at P ≥ 0.05 (Tukeys Test))
7.22
7.2 Effect of time and depth of flooding on plant height of F. miliacea
(Means within columns with same alphabets are not significantly
different at P ≥ 0.05 (Tukeys Test))
7.22
7.3 Effect of time and depth of flooding on root length of F. miliacea
(Means within columns with same alphabets are not significantly
different at P ≥ 0.05 (Tukeys Test))
7.23
7.4 Effect of time and depth of flooding on number of leaves of F.
miliacea (Means within columns with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
7.23
7.5 Effect of time and depth of flooding on dry weight (g/pot) of F.
miliacea (Means within columns with same alphabets are not
significantly different at P ≥ 0.05 (Tukeys Test))
7.24
7.6 Relationship between productive tillers and leaf chlorophyll
content
7.24