Nitrogen partitioning and remobilization in field-grown apple trees

152 Pages·2011·1.75 MB·English

AN ABSTRACT OF THE THESIS OF
Habib Khemira for the degree of Doctor of Philosophy in Horticulture presented on
December 1. 1995. Title: Nitrogen Partitioning and Remobilization in Field-grown
Apple Trees.
Abstract approved:
timothy L. Righ^ti
Anita N. Azarenko
Uptake and cycling of nitrogen (N) in mature trees are not well understood.
Fertilizer-N uptake, partitioning, and use-efficiency were studied in standard strain
'Topred Delicious' and spur strain 'Redspur Delicious' mature apple trees {Malm
domestica Borck) on 'Mailing 7A' (M.7A) rootstocks. The treatments consisted of a
ground application in spring, a preharvest ground application in August, a foliar spray
in fall, or a combination of each of the last two treatments with the first. When soil-
applied in spring, labeled N (15N) was allocated preferentially to above ground tissues
and to a lesser extent to roots of both strains. The amount of newly absorbed soil-N
allocated to above ground tissues decreased as the season progressed, little 15N from pre-
harvest ground applications reached the leaves, fruit, buds, or branches, while roots were
heavily labeled.
Total fertilizer-N recovery in the trees was similar regardless of the time of
fertilizer application. However, losses of 15N to fruit removal, leaf fall, and pruning
were most severe when N was applied in spring and minimal for the pre-harvest timing
compared to all others. About a third of the variability in recovery was due to variation
in tree size. When recoveries were adjusted to account for size differences, spur-type
trees tended to be more efficient at utilizing fertilizer-N.
When 15N-urea was applied in April to young apple leaves, the label was not
exported. Labeled N from fall urea sprays was exported from the leaves to the buds, but
was restricted to the treated spurs and branches. Foliar urea sprays immediately after
harvest contributed more N to the buds than later applications.
Mobilization of 15N from storage in various tree parts was assessed. In
moderately vigorous trees, N stored in aerial parts of the tree was mobilized first,
followed by simultaneous mobilization of root and soil N. Utilization of root reserves
depended on the N status of the tree. When the buds were low in N but the roots had
adequate N reserves, root to shoot N transport started early in winter.
Nitrogen Partitioning and Remobilization in
Field-grown Apple Trees
by
Habib Khemira
A THESIS
submitted to
Oregon State University
in partial fulfillment of
the requirements for the
degree of
Doctor of Philosophy
Completed December 1, 1995
Commencement June 1996
© Copyright by Habib Khemira
December 1, 1995
All Rights Reserved
Doctor of Philosophy thesis of Habib Khemira presented on December 1, 1995
APPROVED:
Co-Major Professof, representing/fiorticulture
Co-Major Professor, representing Horticulture
-
as
Head of Department of Horticultu
36
Dean of Graduate/School
I understand that my thesis will become part of the permanent collection of Oregon State
University libraries. My signature below authorizes release of my thesis to any reader
upon request.
Pi
4,/7/|1l6
Habib Khemira, Author
ACKNOWLEDGEMENTS
As this phase of my life comes to an end, I wish to take the time to thank the
many people whom I came to know and appreciate and whose friendships will be
remembered for years to come...
My thanks go first to my major professors, Drs. Timothy Righetti and Anita
Azarenko, their friendship is so dear to me. Working with Tim has been a wonderful and
enriching experience. Without his enthusiasm, optimism, and support I would have never
been able to finish my degree. I worked with Anita for six years! all along she has been
the resourceful advisor and caring friend.. From her I learned much about science and
life.
I would like to express my gratitude to my sponsors: U.S. Agency for
International Development, The Tunisian Ministry of Higher Education, The Washington
Tree Fruit Research Commission, and Oregon State University for their financial support
during my studies.
I would like also to thank my committee members Drs. Pat Breen, Daniel Arp,
and Gary Jolliff for their patience and sound advice.
My life in Corvallis has been full of good memories and beautiful friendships.
Many are those who I'm indebted to for their trust and support during the difficult times
I went through... I would like to mention my graduate student buddies: Claudia "Che",
Kirk "the Captain", Glen (I enjoyed being his roommate for about three years! of course
the cookies helped :)), Yerko, Anne, Becky, Kais (my thanks for all the help !), Carlos,
Ana, Mike, Clare, Ruth, Kari, Pilar, Roberto, Anawat, David S., Kai, and many others;
the Tunisian community: Mourad, Hammadi, Karim, Rahma, and "little" Hamza :).
My very special thanks to Gaby and Daphne, their friendship will never be
forgotten...Nevia, Carmo, and Giovanna, Corvallis would not be the little town I love,
without them.
My life has been enriched in many ways by knowing a very dear friend, Alex;
my deepest appreciation for her friendship and unfailing good nature.
I wish to thank Drs Pat Breen, who always inspired me to be a better scientist.
Porter Lombard who helped me get started at O.S.U., David Sugar, Enrique Sanchez,
Daryl Richardson, Bill Mansour, and Larry Dalley for their friendship.
The outstanding technical help of Viki Freeman, Colleen Calderwood, and the
farm crew especially Jim, Willy, Katy, and Sally is highly appreciated.
Finally, my deepest gratitude goes to my family: my mom Saida, my father
M'hamed, my grand parents, and my sisters and brothers, to whom I can at last reply
"I'm done !!".
TABLE OF CONTENTS
Page
CHAPTER 1. INTRODUCTION 1
CHAPTER 2. LITERATURE REVIEW 7
1. Overview 7
2. Nitrogen Fertilization Practices 9
2.1 Soil fertilization 9
2.1.1 Spring fertilization 9
2.1.2 Summer fertilization 11
2.1.3 Autumn fertilization 11
2.2 Foliar feeding 12
2.2.1 Factors affecting efficiency of 13
foliar sprays
2.2.2 Practical considerations 15
3. Nitrogen Utilization Efficiency 17
3.1 Definition 17
3.2 Factors affecting efficiency 19
4. Internal Cycling of Nitrogen in Deciduous 20
Trees
4.1 Nitrogen distribution in summer 21
4.2 Leaf senescence and nitrogen 21
remobilization
4.3 Nitrogen storage 23
4.3.1 Sites of storage 23
4.3.2 Chemical nature of storage 25
compounds
4.3.3 Vegetative storage proteins 26
TABLE OF CONTENTS (Continued)
Page
CHAPTER 3. NITROGEN PARTITIONING IN APPLE IS AFFECTED . 28
BY TIMING AND TREE GROWTH HABIT
1. Abstract 28
2. Introduction 29
3. Materials and Methods 30
4. Results and Discussion 33
5. Literature Cited 45
CHAPTER 4. NITROGEN UPTAKE AND RECYCLING EFFICIENCY IN 49
STANDARD- AND SPUR-TYPE APPLE TREES
1. Abstract 49
2. Introduction 50
3. Materials and Methods 51
4. Results and Discussion 54
5. Literature Cited 62
CHAPTER 5. DISTRIBUTION OF UREA-DERIVED NITROGEN .... 65
SUPPLIED TO APPLE LEAVES
1. Abstract 65
2. Introduction 65
3. Materials and Methods 67
4. Results and Discussion 69
5. Literature Cited 75
TABLE OF CONTENTS (Continued)
Page
CHAPTER 6. REMOBILIZATION OF N FROM STORAGE POOLS OF 78
MATURE APPLE TREES DEPENDS ON N STATUS
1. Abstract 78
2. Introduction 79
3. Materials and Methods 81
4. Results and Discussion 84
5. Literature Cited 92
CHAPTER 7. CONCLUSION 95
BIBLIOGRAPHY 97
APPENDICES Ill
APPENDIX A BIURET TOXICITY TO APPLE FOLIAGE SPRAYED . 112
WITH UREA
APPENDIX B CHARACTERIZATION OF NITROGEN POOLS IN .. . 119
MATURE APPLE TREES AND THEIR CONTRIBUTION TO
SPRING GROWTH