SUSTAINABLE MANAGEMENT OF BOTRYTIS BLOSSOM BLIGHT IN WILD BLUEBERRY (VACCINIUM ANGUSTIFOLIUM AITON) by Abbey, Joel Ayebi Submitted in partial fulfilment of the requirements for the degree of Master of Science at Dalhousie University Halifax, Nova Scotia October, 2017 © Copyright by Abbey, Joel Ayebi, 2017 i TABLE OF CONTENTS LIST OF TABLES ............................................................................................................. vi LIST OF FIGURES ........................................................................................................... ix ABSTRACT ........................................................................................................................ x LIST OF ABBREVIATIONS AND SYMBOLS USED ................................................... xi ACKNOWLEDGEMENTS .............................................................................................. xii CHAPTER 1: INTRODUCTION ....................................................................................... 1 1.0. Introduction ............................................................................................................. 1 1.1. Hypothesis and Objectives ....................................................................................... 3 1.1.1. Hypothesis .......................................................................................................... 3 1.1.2. Objectives: .......................................................................................................... 4 1.2. Literature review ....................................................................................................... 5 1.2.1. Taxonomy and botany of wild blueberry ........................................................... 5 1.2.2. Production and characteristics ............................................................................ 6 1.2.3. Botrytis spp. and Botrytis cinerea Pers.:Fr ......................................................... 8 1.2.3.1. Morphology ..................................................................................................... 8 1.2.3.2. Life cycle ......................................................................................................... 9 1.2.3.4. Pathogenicity ................................................................................................. 11 1.2.4 Botrytis management strategies ............................................................................ 13 1.2.4.1. Cultural methods ........................................................................................... 13 1.2.4.2. Biological methods ........................................................................................ 15 1.2.4.3. Chemical control ........................................................................................... 17 1.2.5. Predictive modelling ............................................................................................ 19 ii 1.2.6. Fungicide resistance ............................................................................................ 19 CHAPTER 2: PRELIMINARY ASSESSMENT OF FUNGICIDE RESISTANCE AMONG BOTRYTIS CINEREA ISOLATES FROM WILD BLUEBERRY FIELDS IN NOVA SCOTIA ............................................................................................................... 22 2.0. Abstract ................................................................................................................... 22 2.1 Introduction ............................................................................................................. 23 2.2. Materials and Methods ........................................................................................... 27 2.2.1. PDA medium preparation and incubation conditions ...................................... 27 2.2.2. Isolation of Botrytis cinerea ............................................................................. 27 2.2.3. Fungicide preparation and sensitivity test ........................................................ 28 2.2.4. Sensitivity of mycelial growth ......................................................................... 28 2.2.5. Statistical analysis ............................................................................................ 30 2.3. RESULTS ............................................................................................................... 31 2.2.1. Sensitivity tests ................................................................................................. 31 2.4. Discussion ............................................................................................................... 35 2.5. Conclusion .............................................................................................................. 42 CHAPTER 3: BOTRYTIS BLOSSOM BLIGHT OF WILD BLUEBERRIES: PHENOTYPE AND FLORAL BUD SUSCEPTIBILITY ............................................... 43 3.0. Abstract ................................................................................................................... 43 3.1. Introduction ............................................................................................................ 44 3.2. Materials and Methods ........................................................................................... 46 3.2.1. Site selection and experimental design ............................................................ 46 3.2.2. Inoculum production and preparation .............................................................. 48 iii 3.2.3. Preparation of plants and inoculation ............................................................... 49 3.2.4. Disease assessment ........................................................................................... 51 3.3. Results .................................................................................................................... 51 3.4. Discussion ............................................................................................................... 56 3.5. Conclusion .............................................................................................................. 59 CHAPTER 4: MANAGING BOTRYTIS BLOSSOM BLIGHT THROUGH FIELD SANITATION, LIME SULFUR AND TRICHODERMA APPLICATION ................... 60 4.0. Abstract ................................................................................................................... 60 4.1. Introduction ............................................................................................................ 61 4.2. Materials and Methods ........................................................................................... 64 4.2.1. Site selection and experimental design ............................................................ 64 4.2.2. Treatment combination and application ........................................................... 65 4.2.3. Disease assessment, yield components and berry yield ................................... 66 4.2.4. Statistical analysis ............................................................................................ 68 4.3. Results .................................................................................................................... 69 4.4. Discussion ............................................................................................................... 80 4.5. Conclusions ............................................................................................................ 83 CHAPTER 5: CONTROL OF BOTRYTIS BLOSSOM BLIGHT IN WILD BLUEBERRIES BY BIOLOGICAL CONTROL AGENTS UNDER FIELD CONDITIONS. ................................................................................................................. 84 5.0 Abstract .................................................................................................................... 84 5.1 Introduction ............................................................................................................. 85 5.2. Materials and Methods ........................................................................................... 89 iv 5.2.1. Site selection and experimental design ............................................................ 89 5.2.2. Treatments and treatment applications ............................................................. 89 5.2.3. Disease assessment, yield components and berry yield ................................... 90 5.2.4. Statistical analysis ............................................................................................ 91 5.3. Results .................................................................................................................... 91 5.4. Discussion ............................................................................................................. 108 5.5. Conclusion ............................................................................................................ 114 CHAPTER 6: CONCLUSION AND RECOMMENDATIONS .................................... 115 6.0 Overview ............................................................................................................... 115 6.1. Overall Conclusions ............................................................................................. 116 6.3. Recommendation .................................................................................................. 118 REFERENCES ..............................................................................................................