목차

Introduction 1
Literature review 6
Chapter 1 Fungicide spray schedules for controlling late blight of potato using BLITECAST system. 17
Abstract. 17
1.1 Introduction 18
1.2 Materials and Methods 20
1.2.1 Experimental design and layout 20
1.2.2 BLITECAST system 21
1.2.3 Fungicide spray schedule used in this experiment 22
1.2.4 Estimation of disease severity 29
1.2.5 Area under the disease progress curve (AUDPC) and relative area under the disease progress curve (rAUDPC) 29
1.2.6 Measurement of weather variables 30
1.2.7 Statistical analysis 30
1.3 Results 31
1.3.1 Field results in 2013. 31
1.3.1.1 Effects of spray schedules on diseases severity (%) and disease progress. 31
1.3.1.2 Effects of spray schedules on percent over disease control 37
1.3.1.3 Effects of spray schedules on AUDPC and rAUDPC 39
1.3.2 Field results in 2014. 41
1.3.2.1 Effects of spray schedules on diseases severity (%) and disease progress 41
1.3.2.2 Effects of spray schedules on percent over disease control 46
1.3.2.3 Effects of spray schedules on AUDPC and rAUDPC 48
1.3.3 Field results in 2015 50
1.3.3.1 Effects of spray schedules on diseases severity (%) and disease progress 50
1.3.3.2 Effects of spray schedules on percent over disease control 56
1.3.3.3 Effects of spray schedules on AUDPC and rAUDPC 58
1.4 Discussion 60
Chapter 2 Development of yield loss assessment model for potato late blight disease 63
Abstract 63
2.1 Introduction 64
2.2 Materials and Methods 66
2.2.1 Experimental design and layout 66
2.2.2 Fungicide spray schedule used in this experiment 66
2.2.3 Estimation of disease severity 68
2.2.4 Estimation of yield loss 68
2.2.5 Models for estimating yield loss 68
2.2.6 Data analysis 69
2.3 Results. 70
2.3.1 Effects of spray schedules on diseases severity (%), AUDPC, yield and yield loss (%) of potato due to late blight infection on Dubaek and Superior cultivars in 2014. 70
2.3.2 Critical point models of yield loss (%) by late blight disease severity (%) at various days after planting for Dubaek and Superior cultivars in 2014. 74
2.3.3 Multiple regressions of yield loss model for Dubaek and Superior cultivar based on disease severity (%) and % disease increment at different days after planting in 2014. 76
2.3.4 Actual and estimated loss (%) in potato tuber yield based on multiple regression equation of yield loss (%) and weekly disease increments on Dubaek and Superior cultivars in 2014. 78
2.3.5 Regression models of yield loss (%) by AUDPC for Dubaek and Superior cultivars in 2014. 80
2.3.6 Effects of spray schedules on diseases severity (%), AUDPC, yield and yield loss (%) of potato due to late blight infection on Dubaek and Superior cultivars in 2015. 81
2.3.7 Critical point models of yield loss (%) by late blight disease severity (%) at various days after planting for Dubaek and Superior cultivars in 2015 85
2.3.8 Multiple regressions of yield loss model for Dubaek and Superior cultivars based on disease severity (%) and % disease increment at different days after planting in 2015 87
2.3.9 Actual and estimated loss (%) in potato tuber yield based on multiple regression equation of yield loss (%) and weekly disease increments on disease severity on Dubaek and Superior cultivars in 2015 89
2.3.10 Regression models of yield loss (%) by AUDPC for Dubaek and Superior cultivars in 2015 91
2.4 Discussion 92
Chapter 3 Phenotypic characterization and fungicide sensitivity of Phytophthora infestans isolates obtained in 2013-2014. 96
Abstract. 96
3.1 Introduction. 97
3.2 Materials and Methods 99
3.2.1 Isolation of pathogen 99
3.2.2 Mating type determination of pathogen 100
3.2.3 Fungicide sensitivity and EC50 assays 101
3.2.4 Fitness assessments based on mating type and metalaxyl sensitive, resistant isolate 103
3.2.5 Race identification. 104
3.3 Results 106
3.3.1 Isolates of P. infestans 106
3.3.2 Mating type of P. infestans isolates 107
3.3.3 Sensitivity of P. infestans isolates to metalaxyl fungicide 108
3.3.4 Response to dimethomorph of P. infestans isolates 111
3.3.5 Response to mandipropamid of P. infestans isolates 115
3.3.6 Response to mancozeb of P. infestans isolates 119
3.3.7 Response to chlorothalonil of P. infestans isolates 123
3.3.8 Response to cyazofamid of P. infestans isolates 127
3.3.9 Response to cymoxanil of P. infestans isolates 131
3.3.10 Response to famoxadone of P. infestans isolates 135
3.3.11 Fitness components and composite fitness index based on mating type, metaxyl sensitive and resistant isolates of Phytophthora infestans 140
3.3.12 Physiological race of P. infestans in Korea 143
3.4 Discussion 149
References 155
Summary in English 179
Summary in Korean 183