DISEASE MANAGEMENT IN APPLES USING TRUNK INJECTION DELIVERY OF PLANT ...

362 Pages·2014·3.54 MB·English

DISEASE MANAGEMENT IN APPLES USING TRUNK INJECTION DELIVERY OF
PLANT PROTECTIVE COMPOUNDS

By

Srdan Goran Acimovic

A DISSERTATION

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

Plant Pathology - Doctor of Philosophy

2014
ABSTRACT
DISEASE MANAGEMENT IN APPLES USING TRUNK INJECTION DELIVERY OF
PLANT PROTECTIVE COMPOUNDS

By

Srdan Goran Acimovic

The two most important pathogens of apple Erwinia amylovora (fire blight) and Venturia
inaequalis (apple scab) require pesticide sprays for control. This leads to accumulating side
effects such as disease resistance, contamination of environment, elevated fungicide residues in
fruit, and increased health risks to consumers and workers. While sprays are effective for disease
control, need for increasing the sustainability of apple production by reducing pesticide use in
the environment incited our research on delivering pesticides via trunk injection. This method
delivers the compound into the canopy via tree xylem and could increase the efficiency in
disease control. To find out how, where and when injected compounds distribute in the apple
tree, thus affecting the efficiency in pest control, we injected imidacloprid through 1, 2, 4, or 8
injection ports per tree. By quantifying leaf residues we demonstrated variable spatial
distribution of imidacloprid in the canopy. Spatial uniformity of distribution increased with more
injection ports and 4 ports provided uniform distribution. To demonstrate the efficiency of
injected compounds in fire blight and apple scab control we injected apple trees with antibiotics,
plant resistance inducers, and fungicides. Antibiotics, potassium phosphites (PJ) and acibenzolar-
S-methyl (ASM) provided weak control of blossom and shoot blight while oxytetracycline was
the most efficient. ASM and PJ significantly expressed PR-1, 2, and 8 protein genes showing
resistance activation in apple leaves (SAR) which suppressed the pathogen. Four injections of PJ
in spring controlled leaf apple scab for 2 seasons, similar to 2 seasons of standard sprays. To
optimize injections for apple scab control we evaluated 1-2 and 4 cross-seasonal and 1-2
seasonal injections of PJ and fungicides. PJ provided better scab control than propiconazole,
cyprodinil and difenoconazole and showed better or equal and more persistent scab control with
fewer injections than sprays. Control varied among canopy organs due to different transpiration,
with best scab control on shoots, fruit, and then spurs. Good scab control is provided by 2-3
spring injections. Residues of synthetic fungicides in fruit were always below the residue
tolerances. Fall injection did not improve apple scab control. To get temporally uniform
imidacloprid distribution in the crown, best results were achieved by injection dose delivery at 4
times, 14 days apart. Injection method comparison showed that drill-based injection of the liquid
imidacloprid formulation provided the highest residue concentration in the canopy when
compared to other injection methods. Comparison of 7 trunk injection devices showed that drill-
based devices did not provide higher residue concentration of cyprodinil and difenoconazole in
apple leaf canopy when compared to needle-insertion device Bite, while Wedgle was similar. All
the injection devices allowed similar apple scab control with fungicides. When monitoring the
rate of trunk injection port healing in apple trees, we found that port closure with callus lasted for
1-1.3 and >2 years depending on the port size and type. Port closure was faster on the ports with
smaller diameters. Around all injection port types, bark cracking due to frost events was higher
in vertical direction of the trunk. The visible port depth declined faster on port from 11/64” drill
bit and on lenticular injection port from double-edge blade, versus the port from 3/8” drill bit.
When the port from 3/8” drill bit was sealed with an Arborplug, visible and covered port depths
significantly increased in time due to callus formation on the top and laterally, around the plug.
Overall, trunk injection of injection formulated pesticides could be a viable option for disease
control in apples with minimal impact of injection ports on the tree.
Copyright by
SRDAN GORAN ACIMOVIC
2014
To my beloved wife Dana, my parents Ivana and Goran and brother Žarko.
Nothing of what I have done would have been possible without you.

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ACKNOWLEDGEMENTS

I thank my advisors Dr. John Wise and Dr. George Sundin for the guidance,
understanding and continuous support in my work. I am grateful to my committee members Dr.
Bert Cregg and Dr. Raymond Hammerschmidt for support with advices and in writing, and
interest in my dissertation projects. Further, I commend Dr. Christine Vandervoort and research
technician Thomas Garavaglia for their expertise in analytical chemistry greatly contributing to
the presented work and for patience and help in training me. Thank you to Dr. Quan Zeng and
research technician Gayle McGhee for sharing their expertise in microbiology, molecular plant
pathology and genetics. At last, I gratefully acknowledge tremendous help in my work provided
by MSU staff Anthony VanWoerkom, Laura Lamb, Christopher Meredith and Ryan Vander
Poppen, and then by Dr. Joseph Doccola and Joe Aiken of Arborjet Inc., and assistance from
graduate and undergraduate students Daniel Hulbert, Raja Zalinda Raja Jamil and James Spica. I
thank also Dr. James Miller and David Mota-Sanchez for guidance and advices in my work and
friendly discussions.
At last, none of the work inside this dissertation would be possible if there was no
funding provided by USDA-PMAP, Michigan Apple Research Committee, A.L. Rogers
Scholarship, IR-4 and Arborjet Inc.

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TABLE OF CONTENTS

LIST OF TABLES .................................................................................................................... xi
LIST OF FIGURES .................................................................................................................. xv
KEY TO SYMBOLS AND ABBREVIATIONS ......................................................................xxi
CHAPTER 1. INTRODUCTION AND LITERATURE REVIEW ..............................................1
Apple production and its significance ...................................................................................1
Fire blight Erwinia amylovora and its significance ...............................................................3
Apple scab Venturia inaequalis and its significance .............................................................7
Brief history and introduction to trunk injection in plant protection .................................... 13
Biological factors influencing injected compound .............................................................. 17
Chemical factors influencing injected compound................................................................ 22
Technological factors influencing injected compound ........................................................ 26
Ecological factors influencing injected compound .............................................................. 29
Hypothesized factors influencing injected compound ......................................................... 31
Control of fire blight (Erwinia amylovora (Burrill) Winslow et al.) on apple using topical
and trunk injection treatments of alternative plant protective compounds ........................... 33
Acibenzolar-S-methyl ...................................................................................................... 33
Mono- and di-potassium salts of phosphorous acid and prohexadione-calcium ................. 42
Prohexadione-carboxylic acid .......................................................................................... 52
Control of apple scab (Venturia inaequalis (Cooke) Winter) using topical and trunk injection
treatments of alternative plant protective compounds and fungicides .................................. 55
Acibenzolar-S-methyl ...................................................................................................... 55
Mono- and di-potassium salts of phosphorous acid (phosphites)....................................... 58
Fungicides ....................................................................................................................... 61
Commercial standards in control of fire blight and apple scab with protective compounds . 63
Fire blight (Erwinia amylovora) ....................................................................................... 63
Apple scab (Venturia inaequalis) ..................................................................................... 65
CHAPTER 2. SPATIAL AND TEMPORAL DISTRIBUTION OF TRUNK-INJECTED
IMIDACLOPRID IN APPLE TREE CANOPY ........................................................................ 67
Abstract ................................................................................................................................ 67
Introduction .......................................................................................................................... 68
Materials and methods .......................................................................................................... 71
Chemical materials ............................................................................................................. 71
Trunk injection ................................................................................................................... 72
Leaf sampling and imidacloprid residue profile analysis ..................................................... 73
Statistical analysis .............................................................................................................. 75
Imidacloprid residue concentration patterns ........................................................................ 75
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Results.................................................................................................................................. 76
Spatial distribution of imidacloprid .................................................................................... 76
Temporal distribution of imidacloprid ................................................................................ 77
Imidacloprid residue concentration patterns ........................................................................ 78
Implications of imidacloprid distribution in apple leaf canopy ............................................ 79
Discussion .......................................................................................................................... 86
The influence of number of injection ports on imidacloprid distribution in apple canopy .... 86
The influence of time on distribution of imidacloprid in apple tree canopy ......................... 87
The influence of xylem anatomy and mechanisms contributing to imidacloprid transport and
distribution in apple tree canopy ......................................................................................... 89
The influence of port position and dose splitting on distribution of imidacloprid in apple tree
canopy ............................................................................................................................... 90
The influence of compound properties and xylem transport capacity on distribution of
imidacloprid in apple tree canopy ....................................................................................... 92
Conclusion ........................................................................................................................... 93
Acknowledgements ............................................................................................................ 94
CHAPTER 3. CONTROL OF FIRE BLIGHT (ERWINIA AMYLOVORA) ON APPLE USING
TRUNK INJECTION DELIVERY OF PLANT RESISTANCE INDUCERS AND
ANTIBIOTICS ......................................................................................................................... 95
Abstract ................................................................................................................................ 95
Introduction .......................................................................................................................... 96
Materials and methods .......................................................................................................... 99
Control of blossom and shoot blight incidence ................................................................... 99
Chemical materials .......................................................................................................... 99
Trunk injection .............................................................................................................. 102
Inoculation ..................................................................................................................... 103
Disease evaluations ........................................................................................................ 103
PR protein gene expression in leaves and flowers ............................................................. 104
Sample collection........................................................................................................... 104
RNA extraction and gene expression .............................................................................. 104
Control of shoot blight severity ........................................................................................ 106
Chemical materials ........................................................................................................ 106
Trunk injection .............................................................................................................. 106
Inoculation ..................................................................................................................... 107
Disease evaluations ........................................................................................................ 107
Statistical analysis ............................................................................................................ 108
Results................................................................................................................................ 109
Control of blossom and shoot blight incidence ................................................................. 109
PR protein gene expression .............................................................................................. 111
Gene expression in apple leaves ..................................................................................... 111
Gene expression in apple flowers ................................................................................... 112
Control of shoot blight severity ........................................................................................ 112
Discussion .......................................................................................................................... 125
Acknowledgements .......................................................................................................... 132
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CHAPTER 4. TRUNK-INJECTED POTASSIUM PHOSPHITES AND OTHER FUNGICIDES
PROVIDE TWO SEASONS OF CONTROL OF APPLE SCAB VENTURIA INAEQUALIS ON
‘RED DELICIOUS’ APPLE TREES....................................................................................... 133
Abstract .............................................................................................................................. 133
Introduction ........................................................................................................................ 134
Materials and Methods ....................................................................................................... 136
Results................................................................................................................................ 139
Discussion .......................................................................................................................... 143
Acknowledgements .......................................................................................................... 147
CHAPTER 5. SEASONAL AND CROSS-SEASONAL TIMING OF FUNGICIDE TRUNK
INJECTIONS ON APPLE TREES TO OPTIMIZE MANAGEMENT OF APPLE SCAB
FUNGUS VENTURIA INAEQUALIS ...................................................................................... 148
Abstract .............................................................................................................................. 148
Introduction ........................................................................................................................ 149
Materials and Methods ....................................................................................................... 153
Trunk injection and apple scab evaluation ........................................................................ 153
Fungicide residue analysis ................................................................................................ 156
Results................................................................................................................................ 159
Apple scab control ........................................................................................................... 159
Residue profiles ............................................................................................................... 160
Discussion .......................................................................................................................... 172
Acknowledgements .......................................................................................................... 177
CHAPTER 6. COMPARISON OF CURRENT AND DEVELOPED TRUNK INJECTION
TECHNOLOGIES IN COMPOUND DISTRIBUTION AND SIMULATION OF SLOW TIME-
RELEASE OF INJECTED COMPOUND FOR LONG-LASTING TREE PROTECTION...... 179
Abstract .............................................................................................................................. 179
Introduction ........................................................................................................................ 180
Materials and Methods ....................................................................................................... 184
Simulation of slow time-release of injected compound and the comparison of three trunk
injection technologies in temporal distribution of imidacloprid ......................................... 184
Comparison of trunk injection devices in temporal distribution of difenoconazole and
cyprodinil in apple canopy and in control of apple scab .................................................... 187
Results................................................................................................................................ 190
Slow time-release of imidacloprid and the differences of three trunk injection technologies
in temporal distribution of imidacloprid ........................................................................... 190
Temporal distribution of difenoconazole and cyprodinil and apple scab control after trunk
injection with different devices ......................................................................................... 191
Discussion .......................................................................................................................... 202
Temporal distribution of trunk-injected imidacloprid can be uniform ............................... 202
Drill-based, needle-based and slow-release trunk injection technologies differ in temporal
distribution of imidacloprid .............................................................................................. 203
Trunk injection devices differ in temporal distribution of difenoconazole and cyprodinil and
in the apple scab control ................................................................................................... 204
Acknowledgements .......................................................................................................... 208
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CHAPTER 7. COMPARISON OF DRILL- AND NEEDLE-BASED TREE INJECTION
TECHNOLOGIES IN HEALING OF TRUNK INJECTION PORTS ON APPLES ................ 209
Abstract .............................................................................................................................. 209
Introduction ........................................................................................................................ 210
Materials and Methods ....................................................................................................... 213
Results................................................................................................................................ 215
Discussion .......................................................................................................................... 221
Conclusion ......................................................................................................................... 228
Acknowledgements .......................................................................................................... 230
CHAPTER 8. CONCLUSION AND FUTURE RESEARCH IN TRUNK INJECTION FOR
FRUIT TREE PROTECTION ................................................................................................. 231
Spatial and temporal distribution of trunk-injected imidacloprid in apple tree canopy ....... 231
Control of fire blight (Erwinia amylovora) on apple using trunk injection delivery of plant
resistance activators and antibiotics .................................................................................. 234
Blossom and shoot blight control ................................................................................... 236
PR-protein gene expression ............................................................................................ 238
Shoot blight control ....................................................................................................... 239
Control of apple scab (Venturia inaequalis) using trunk injection delivery of bio-pesticides
and fungicides .................................................................................................................. 241
Control of apple scab using trunk injection of biopesticides based on phosphorus acid salts
in 2012 and continuation of apple scab control in 2013 .................................................. 242
Optimization of trunk injection timing for control of apple scab in 2012 and 2013 ......... 244
Trunk injection technology simulations and comparisons ................................................. 256
Simulation of slow compound release ........................................................................... 256
Comparison of the three main trunk injection technologies in compound delivery .......... 258
Comparison of seven trunk injection tools in compound delivery and disease control .... 260
Comparison of trunk injection elements in injection port wound healing ........................ 263
Closing comments ............................................................................................................ 266
APPENDICES ........................................................................................................................ 268
APPENDIX 1. Preliminary research in 2011 and 2012 on control of fire blight using trunk
injection of protective compounds ...................................................................................... 269
APPENDIX 2. Figures and tables including complete PR-protein gene expression analyses for
fire blight control, treatments evaluated for apple scab control and fungicide residues ........ 285
APPENDIX 3. Media, buffers and primers ......................................................................... 302
REFERENCES ....................................................................................................................... 303

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