FRUIT TRAITS ASSOCIATED WITH RESISTANCE TO FRUIT PESTS OF HOT PEPPER IN UGANDA

BY

SSEKKADDE PETER

2015/HD02/517U

B.SC. AGRIC (HONS) (MUK)

A THESIS SUBMITTED TO THE DIRECTORATE OF RESEARCH AND GRADUATE TRAINING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF MASTER OF SCIENCE IN CROP SCIENCE OF MAKERERE UNIVERSITY

APRIL 2021

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DEDICATION To my parents, Mr. and Mrs. Getrude and Stephen Kasumba and my sisters who selflessly supported me throughout this study.

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ACKNOWLEDGEMENTS

I acknowledge the Africa-Brazil Agricultural Innovations Marketplace that provided the scholarship for the MSc program through project #2685 on “Enhancing livelihoods of small- scale hot pepper farmers through partnerships for germplasm improvement and adaptation.”

I greatly appreciate my first supervisor, Assoc. Prof Jeninah Karungi for considering me for this sponsorship and her precious mentorship in research. I greatly appreciate her invaluable and selfless support and guidance rendered to me during all the phases of this study. I will forever be grateful for having gone through her hands.

With gratitude I acknowledge the patience, guidance and positive criticism provided to me by my second supervisor, Dr. Cláudia Ribeiro of Embrapa-Brazil that have made this research a success.

Since my undergraduate studies, Dr. Ochwo-Ssemakula M.K.N, has guided and encouraged me to always push forward in the academic field. Even in the course of this study, her contribution has been immense. I consider her a special gift to my life and may God richly reward her efforts in getting the best out of me.

I thank my dear parents Mr. Stephen and Mrs. Getrude Kasumba who have always encouraged and supported me throughout my life. I am forever indebted to these special people. May the Almighty God give you long life.

Michelle, Mildred and Millicent, my sisters provided me with the encouragement that fueled my progress and I am forever thankful they did.

The role of my colleagues in this study cannot be underestimated. I greatly appreciate my fellow MSc students for accepting to take this academic journey with me.

I salute the Makerere University Agricultural Research Institute Kabanyolo team especially Salongo Nkajja Bonny who played a key role in helping with the setting up and management of the experiments. I hail the farmers who positively contributed to this study especially Mr. Kakaya Julius of Ibanda district.

Above all, I am greatly indebted to the Almighty God for the gift of life, health and this opportunity He availed me. I am forever grateful for His mercy towards me.

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TABLE OF CONTENTS

DECLARATION ...... I

DEDICATION ...... II

ACKNOWLEDGEMENTS ...... IV

TABLE OF CONTENTS ...... V

ACRONYMS ...... IX

LIST OF FIGURES ...... X

LIST OF TABLES ...... XI

APPENDICES ...... XII

ABSTRACT ...... XIII

CHAPTER ONE ...... 1 1.0 INTRODUCTION ...... 1

1.1 Background ...... 1

1.2 Problem statement ...... 3

1.3 Major Objective...... 3

1.3.1 Specific Objectives ...... 3

1.4 Hypotheses of the study ...... 3

1.5 Justification ...... 4

CHAPTER TWO ...... 5

LITERATURE REVIEW...... 5

2.1 Origin, Classification, Taxonomy and Morphology of pepper ...... 5

2.2 Chemical and nutritional composition of hot pepper ...... 8

2.3 Ecological and agronomic requirements of hot pepper ...... 9

2.4 Quarantine pests of hot pepper ...... 10

Fruit flies (Diptera: Tephritidae) ...... 10 v

2.4.1.1 Description and biology of fruit flies ...... 10 2.4.1.2 Host range, damage and economic importance of fruit flies ...... 11 2.4.1.3 Management of fruit flies ...... 11

The false codling moth (Thaumatotibia leucotreta (Meyrick)) ...... 12

2.4.2.1 Description and biology of the false coddling moth ...... 13 2.4.2.2 Host range, damage and economic importance of the false coddling moth ...... 14 2.4.2.3 Management of the false coddling moth ...... 14

2.5 Capsicum diversity for improving hot pepper resistance to pest infestation ...... 15

2.5.1 Morphological and biochemical traits influencing fruit pest infestation and utilization…… ...... 16

2.5.1.1 Host colour ...... 16 2.5.1.2 Olfactory cues ...... 17 2.5.1.3 Ripeness of the fruit...... 17 2.5.1.4 Fruit size and shape ...... 17 2.5.1.5 Fruit firmness and toughness ...... 18

2.6 Relationship between fruit traits and yield of hot pepper ...... 18

CHAPTER THREE ...... 20

3.0 MATERIALS AND METHODS ...... 20

3.1 Study site ...... 20

3.2 Source of hot pepper germplasm and seedling raising ...... 20

3.3 Study Design ...... 21

Data collection ...... 21

Data analysis ...... 22

CHAPTER FOUR ...... 25

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4.0 RESULTS AND DISCUSSIONS ...... 25

4.1 EFFECT OF HOT PEPPER GENOTYPES ON FRUIT PEST INFESTATION ...... 25

4.1.1 Effect of hot pepper genotypes and seasons on fruit damage ...... 25

4.1.2 Effect of hot pepper genotypes and seasons on fruit fly infestation and fruit fly larva per fruit…………………………………………………………………………………………...25

4.1.3 Effect of hot pepper genotypes on false coddling moth infestation ...... 26

4.2 RANKING OF THE REACTION OF HOT PEPPER GENOTYPES TO FRUIT FLY ATTACK ...... 28

4.3 FRUIT QUALITY TRAITS OF DIFFERENT HOT PEPPER GENOTYPES ...... 30

4.4 EFFECT OF HOT PEPPER GENOTYPES ON YIELD PERFORMANCE ...... 34

4.4.1 Total fruit yield (tha-1) ...... 34

4.4.2 Number of fruits per plant ...... 35

4.4.3 Marketable fruits (%) ...... 35

4.5 Coefficients of correlation for the relationships between fruit pest infestation and fruit traits of hot pepper genotypes evaluated in MUARIK ...... 37

4.6 Correlation coefficients for the relationships between yield and fruit traits of hot pepper genotypes pooled over the two seasons at MUARIK and on farmer-field ...... 38

4.7 DISCUSSION ...... 40

4.7.1 Effect of hot pepper genotypes and seasons on fruit damage ...... 40

4.7.2 Effect of hot pepper genotypes and season on fruit fly infestation ...... 40

4.7.4 Ranking of the reaction of hot pepper genotypes to fruit fly attack ...... 42

4.7.5 Effect of fruit traits on fruit damage...... 42 vii

4.7.6 Effect of fruit traits on fruit fly infestation ...... 42

4.7.7 Effect of fruit traits on false codling moth (FCM) infestation of hot pepper genotypes…...... 43

4.7.8 Hot pepper fruit traits and yield performance ...... 44

CHAPTER FIVE ...... 45

5.0 GENERAL DISCUSSION, CONCLUSIONS AND RECOMMENDATIONS ...... 45

5.1 General discussion...... 45

5.2 Conclusions ...... 45

5.3 Recommendations ...... 46

REFERENCES ...... 47 APPENDICES ...... 63

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ACRONYMS

MAAIF Ministry of Agriculture, Animal Industry and Fisheries MANFQ Ministry of Agriculture, Nature and Food Quality MEMD Ministry of Energy and Mineral Development REA Rural Electrification Agency

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LIST OF FIGURES Figure 1. Distinguishing characteristics of Capsicum annuum; white corolla (A), variety of fruit shapes (B & C)...... 6 Figure 2. Distinguishing characteristics of Capsicum chinense; green corolla and blue anthers (A), a variety of fruit shapes and colours (B & C)...... 6 Figure 3. Distinguishing characteristics of Capsicum frutescens; greenish white without spots and the anthers are purple (A), numerous small pointed fruits (B) and compact plant growth habit (C)...... 7 Figure 4. Distinguishing feature of Capsicum baccatum; yellow spots on the corolla (A) ...... 7 Figure 5. Distinguishing features of characteristics of Capsicum pubescens; Purple corolla and purple and white anthers (A), pear or apple shaped fruits (B) and black seeds (C). (Source: Wikipedia, 2018) ...... 8

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LIST OF TABLES Table 1a. Exotic germplasm, source/origin, type, fruit characteristics ...... 24 Table 2. Damage and infestation by fruit pests of hot pepper genotypes evaluated in MUARIK, Uganda in season 2017Aand 2018B ...... 27 Table 3. Percentage fruit pest infestation by fruit pests in on-farm hot pepper trial ...... 28 Table 4. Pooled fruit damage, number of fruit fly larva per fruit and reaction of hot pepper genotypes common to both seasons to fruit fly attack evaluated at MUARIK ...... 29 Table 5. Fruit damage, number of fruit fly larva per fruit and reaction of hot pepper genotypes common to both seasons to fruit fly attack evaluated on farmer-field in Ibanda district ...... 30 Table 6. Means of fruit quality traits for hot pepper genotypes evaluated in MUARIK, Uganda in season 2017Aand 2018B ...... 33 Table 7. Fruit quality traits of hot pepper genotypes evaluated on farmer-field in Ibanda, District...... 34 Table 8. Yield performance of hot pepper genotypes evaluated in MUARIK, Uganda in season 2017Aand 2018B ...... 36 Table 9. Yield parameters of genotypes evaluated on farmer-field in Ibanda district ...... 37 Table 10. Correlation coefficients for the relationship between fruit pest infestation and hot pepper fruit traits pooled over the two seasons at MUARIK ...... 38 Table 11. Correlation coefficients for the relationship between fruit pest infestation and fruit parameters of genotypes evaluated on farmer- field ...... 38 Table 12. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes common in both seasons A and B evaluated in at MUAURIK ...... 39 Table 13. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes evaluated on the farmer field in Ibanda district ...... 39

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APPENDICES Appendix 1.Pooled analysis of variance for pest infestation, fruit traits and yield for 48 hot pepper genotypes with pepper type as a covariate ...... 63 Appendix 2.Correlation coefficients for the relationship between fruit pest infestation and fruit parameters of hot pepper genotypes in season 2017Aevaluated at MUARIK ...... 64 Appendix 3.Correlation coefficients for the relationship between fruit pest infestation and fruit parameters of hot pepper genotypes in 2018B evaluated at MUARIK ...... 64 Appendix 4. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes evaluated in season 2017Aat MUAURIK ...... 65 Appendix 5. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes evaluated in 2018B at MUAURIK ...... 65 Appendix 6. Monthly weather data for Season 2017A(December, 2016-June, 2017) hot pepper trial conducted in MUARIK...... 65 Appendix 7. Monthly weather data for 2018B (September, 2017-March, 2018) hot pepper trial conducted in MUARIK...... 66

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ABSTRACT

Hot pepper (Capsicum spp) is an important economic crop for small-scale farmers. However, its production and profitability is hindered by infestations of fruit flies and the invasive false coddling moth (FCM). These fruit damaging pests are of quarantine importance and face stringent restrictive regulations imposed by importing countries. Farmers in effort to protect their produce, resort to use pesticides, albeit inappropriately. This increases the likelihood of rejection of export produce at the international market due to the failure to meet acceptable maximum pesticide residue levels in export produce. Pests can cost effectively be managed by exploiting host plant resistance which can also easily be used with other management practices. The main objective of this study was to improve the competitiveness of Ugandan hot pepper exports on the international market by developing knowledge for use in host plant resistance against quarantine fruit pests. To achieve this, studies were conducted to; a) assess the levels of resistance of hot pepper genotypes of different Capsicum spp to fruit pests; b) establish morphological fruit traits associated with resistance to fruit pests’ infestation and to fruit yield.

A total of fifty-one (51) hot pepper genotypes, thirty-seven (37) local and 14 exotic, were screened for resistance against fruit pests under field conditions at Makerere University Agricultural Research Institute Kabanyolo (MUARIK) from 2016 to 2018. Fifteen genotypes were further evaluated on farm in Ibanda district. Data were collected on fruit damage, fruit fly, and FCM infestation and fruit traits (fruit weight, length, width, flesh penetrability, and fruit wall thickness) and yield.

Results showed variation in performance of the hot pepper genotypes, in terms of resistance to fruit pests’ infestation and yield. Genotypes CAP0408-12, UG-WE02-1014, UG-WE02-0711, UG-EA06-0515 and UG-WE02-1608 were the most promising in terms of resistance to fruit flies though they had low yields. Genotypes UG-WE02-1802, UG-WE02-1909, UG-CE01- 0401, UG-WE05-0607 and UG-CE01-0805 had the highest yields but were more susceptible to fruit damaging pests. Fruit fly infestation correlated positively and significantly with number of fruit fly larvae, average fruit weight, fruit length, fruit width, and fruit penetration force (r=0.56, r=0.59, r=0.30, r=0.63, and r=0.24, respectively). False coddling moth infestation similarly correlated to average fruit weight, fruit length, fruit width (r=0.50, r=0.17, r=0.50, respectively), but had no significant relationship with penetration force. Size (fruit width and weight) was the major fruit trait that influenced pest infestation of the genotypes. Generally, heavy and broad hot pepper fruits were more prone to infestation by the fruit pests. xiii

Genotypes, CAP0408-12, UG-WE02-1014, UG-WE02-0711, UG-EA06-0515 and UG-WE02- 1608 showed substantial resistance to both fruit flies and the false coddling moth. Therefore, they should be followed up for utilization in breeding programs for their resistance to the studied fruit pests.

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CHAPTER ONE

1.0 INTRODUCTION

1.1 Background Pepper (Capsicum spp.) belongs to the Solanaceae (nightshade) family with other important vegetables such as tomato (Solanum lycopersicum. L), eggplant (Solanum melongena) and potato (Solanum tuberosum) (Acquaah, 2009). Capsicum spp is native to both the tropical and temperate regions of Americas including Brazil (Eshbaugh, 1993). The genus Capsicum represents a diverse plant group ranging from the popular sweet green bell pepper (Capsicum annuum) to the high-heat hot pepper (Capsicum chinense) varieties (Bosland et al., 2012). Pepper have a variety of names depending on the location and type (Bosland, 1996) but as pertains to this study, it is referred to as hot pepper since the focus is on the ‘hot’ or pungent types.

The genus Capsicum comprises 35 taxa (species and varieties) that generally possess a bushy shape and produce sweet or hot fruits. Of these, only five species are domesticated; Capsicum annum, C. frutescens, C. chinense, C. baccatum and C. pubescens. The latter being the most widely cultivated (Fonseca et al., 2008; Bozokalfa et al., 2009).

Peppers are used as vegetables, spices, beverages and condiments; constituents of many foods, adding flavour, and colour (Arimboor et al., 2015). Hot peppers are a rich source of carotenoids and vitamins C (Pawar et al., 2011). The capsaicinoids, responsible for the pungency of hot peppers, exert multiple pharmacological and physiological effects including pain relief, and treatment of fevers, arthritis, hernia, migraines, colds and constipation alleviation (Palevitch & Craker, 1995; Bosland, 1996; Tabuti et al., 2003; Dagnoko et al., 2013). Hot peppers, especially Capsicum frutescens are used to treat New Castle and Fowl Pox in organic poultry production (Adedeji et al., 2013). Farmers also use them locally as pesticides or their constituents (Tabuti et al., 2003; Watuleke, 2015) to control pests such as termites (Nyeko & Olubayo, 2005).

Hot pepper dominates the world spice trade, while sweet pepper is a popular vegetable in the tropics (Bozokalfa et al., 2009; Lin et al., 2013). In 2016, the world production area for pepper was estimated at 3.7 million ha with 3.2 million ha situated in developing countries of Asia (2.5m ha) and Africa (0.7m ha). The overall world production of hot pepper in 2016 was 38.4 million tons (m t). The leading producers were China (17.7m t), Mexico (2.7m t) and India 1

(1.4m t). Africa contributed 4.3m t to the total world production with Nigeria (0.8m t), Egypt (0.6m t) and Algeria (0.6m t) as the leading producers, respectively (FAOSTAT, 2018).

Hot pepper is an important cash crop for small-scale farmers in developing countries (Bozokalfa et al., 2009; Lin et al., 2013). In Uganda, hot pepper is highly valued and majorly produced for export though it is also consumed locally (Karungi et al., 2011; Acaye & Odongo, 2018). Scotch bonnet (Capsicum chinense) is the most popular hot pepper type grown purposely for its unique flavor or high pungency (Sonko et al., 2005). Other types include Habanero (Capsicum chinense), African bird eye chili (Capsicum frutescens), Long cayenne (Capsicum annum), Short thai (Capsicum annum) and Bullet chili (Capsicum annum) in order of decreasing production (Besigye, 2015).

The average yields of hot pepper range from 8 to 12 tons per hectare (t/ha) although they can be increased to 20-50 t/ha with irrigation and other good management practices. The annual production of hot pepper in Uganda ranges between 200-250 t (Sonko et al., 2005). The major export market for Ugandan hot pepper is the United States of America and the European Union, especially Netherlands and United Kingdom (EPPO, 2013; Besigye, 2015; PARM, 2017). Hot pepper is a non-traditional export crop diversifying exports in Uganda (Jaimovich & Kamuganga, 2011). Therefore, the crop has gained more importance, especially, among small- scale farmers and is gradually supplanting coffee in Mukono District (Ntambirweki-Karugonjo & Barungi, 2012). It has the potential to improve the livelihoods of small-scale farmers in Uganda by alleviating poverty (Buyinza & Mugagga, 2010). Despite all this, its production and productivity remain low (Karungi et al., 2013). This is attributed to lack of improved varieties, poor seed systems, insect pests, diseases and abiotic factors such as drought (ADC/IDEA, 2001; Horton, 2008; Buyinza & Mugagga, 2010; Mundt, 2014). Pests include fruit flies, aphids, white flies, thrips, fruit worms and pepper weevils. These cause substantial losses in yield and fruit quality of the crop whenever grown (Djieto-Lordon et al., 2014; Muzira et al., 2015). Fruit flies have been reported to cause yield losses of more than 37% (Muzira, 2015). In fact, there had been a steady increase in hot pepper export volume from 2010 (111 t) to 2013 (405 t) before a sharp decline in 2014 (196 t) (UBOS, 2015; 2017). The profound decline is associated with interception of the false coddling moth (FCM) from Ugandan produce on the international market (Besigye, 2015; PARM, 2017). This pest continues to be a challenge to the export of hot pepper to date.

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1.2 Problem statement

Pests can be managed cost effectively and safely by exploiting host plant resistance (Mundt, 2014). In Uganda, host plant resistance has not been fully exploited for improvement of hot pepper against fruit pests. This may be due to the insufficient knowledge of resistance of the existing germplasm or not having enough genetic variation in existing germplasm. Nsabiyera (2012) screened 9 local and 26 exotic hot pepper genotypes from Taiwan belonging to one species, Capsicum annum against diseases but not fruit insect pests. This being the only such study on hot pepper underscores the need for assembly and screening of more hot pepper germplasm to increase chances of finding sources of resistance to fruit pests.

The center of origin of hot pepper is believed to be in Central and South America (Pickersgill, 1997) with Brazil, Bolivia and Mexico having the greatest share of the species (Clement et al., 2010; Loaiza-Figuero et al., 1989; Pickersgill & Heiser, 1977). Yet, no effort had so far been made to source and evaluate germplasm from these regions. Therefore, there is need to assemble and screen more local and foreign genotypes of different Capsicum species to provide a broader genetic base for breeding especially for resistance against fruit pests and yield improvement.

1.3 Major Objective To generate knowledge to support breeding for host plant resistance against quarantine fruit pests of hot pepper in Uganda.

1.3.1 Specific Objectives I. To assess the levels of resistance of hot pepper genotypes of different Capsicum spp to fruit pests, and II. To establish morphological fruit traits associated with resistance to fruit pests’ infestation and to fruit yield.

1.4 Hypotheses of the study I. There is variation in the reaction of different genotypes to fruit pest attack due to fruit morphological traits. II. Fruit morphological traits that associated with fruit pest damage also significantly contribute to yield.

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1.5 Justification Fruit damaging pests such as fruit flies, bollworms and the false coddling moth (FCM) are important since they cause profound direct yield losses (Djieto-Lordon et al., 2014). Fruit flies and the FCM are quarantine pests with stringent restrictive regulations imposed by importing countries (Barnes et al., 2015; Besigye, 2015; van Meggelen, 2015). Annual revenue from hot pepper exports declined sharply from USD 1.74m in 2013 to USD 0.57m in 2014, registering a loss of about 67% due to the FCM (PARM, 2017; UBOS, 2017). In 2014, key stakeholders imposed a self-ban on the export of fresh hot pepper due to the pest (Besigye, 2015).

Farmers in pursuit to protect their produce, resort to use of pesticides though in most cases inappropriately (Karungi et al., 2013). This increases the likelihood of rejection of export produce on the international market. This rejection is triggered by failure to comply with the stringent safety standards regarding the acceptable maximum pesticide residue levels in export produce (UIA, 2009). The use of pesticides also implies higher production costs (Gupta & Dikshit, 2010), adverse effects on human health, damage to the environment as well as pest resistance and resurgence (Mazid et al., 2011).

In order to ensure and maintain hot pepper farming as a lucrative investment for smallholder growers seeking a better livelihood; safer and effective means of alleviating pest and disease threats ought to be considered. Exploitation of host plant resistance is hailed as the most favourable option for environmental, economic, and social reasons (Mundt, 2014). Cooperation with Brazilian Agricultural Research Corporation (Embrapa) availed germplasm from one of the centers of diversity, Brazil. The more diverse the germplasm, the more options farmers will have. The use of host plant resistance against hot pepper fruit pests will reduce pesticide usage and offer protection to farmers, consumers and exports. This study screened both local and exotic germplasm for resistance to fruit pests. There was need to conduct a country wide survey in the major hot pepper growing districts to obtain diverse hot pepper germplasm and screen it under field conditions to ascertain their resistance tos fruit pests.

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CHAPTER TWO

LITERATURE REVIEW

2.1 Origin, Classification, Taxonomy and Morphology of pepper Hot pepper and other peppers (Capsicum spp) belong to the same family Solanaceae (Bozokalfa & Esiyok, 2011) with other crops of economic importance, notably; - tomato, tobacco and potato. It belongs to the tribe Solaneae and subtribe Capsicinae (Dias et al., 2013). The genus Capsicum consists of 30 known species (Bozokalfa et al., 2009). According to Pickersgill (1997), capsicums originated from Central and South America but at the present are widely spread throughout the world in the tropics, subtropics and temperate regions where their fruits are valued for their flavour.

Though the center of diversity of Caspicum genus is said to be South America with Brazil and Bolivia having the largest share of species, the different species originated from specific areas within this region (Clement et al., 2010). According to Loaiza-Figuero et al. (1989), Mexico is the center of domestication for C. annuum while that of C. chinense is Brazil. The Amazonia may also be the center for C. frutescens (Pickersgill & Heiser, 1977) though Mexico and Central America are also the likely origin. Bolivia is the center of origin for C. baccatum (Clement et al., 2010) and Capsicum pubescens (Eshbaugh, 1983).

There is a historic association of Columbus’ voyages to the New World and hot pepper and he is credited for introducing chili to Europe, Africa and to Asia (Bosland, 1996). Capsicum species, most especially C. annuum, are now spread worldwide, are important in many local cuisines, and are a source of income to farmers (Van Zonneveld et al., 2015).

Hot peppers are annual herbs but may also be perennial (Walsh and Hoot, 2001; Bozokalfa et al., 2009). Division of capsicum species can also be based on their fruit properties such as pungency, color, shape, intended use, flavor, and size (Tesfaw et al., 2013). These traits are also useful in choice of cultivars and breeding programs.

Capsicum annuum was domesticated in Mexico and comprises most of the Mexican chili peppers, most of the hot peppers of Africa and Asia as well as numerous sweet pepper cultivars in temperate regions (Pickersgill, 1997). This species includes the ancho, bell pepper, cayenne, cherry, cuban, de arbol, jalapeno, mirasol, ornamental, new mexican, paprika, pimiento, pequin, serrano, squash and wax pod types. They have white corolla (petals) and a variety of 5

pod shapes (Figure 1). They have been categorized as sweet (or mild) peppers and hot Chile peppers but modern plant breeding has erased their distinctness by breeding hot bell varieties and sweet Jalapenos (McMullan & Livsey, 2007).

A B C

Figure 1. Distinguishing characteristics of Capsicum annuum; white corolla (A), variety of fruit shapes (B & C).

Capsicum chinense originates from Amazon though the term “chinense” simply means ‘from China’. The hottest peppers in the world such as the trinidad moruga scorpion, scotch bonnet, the legendary red savina belong to this species and are popular in most tropical regions (Hundal & Dhall, 2005; McMullan & Livsey, 2007; Arimboor et al., 2015). The shape of the fruit ranges from long and slender to short and obtuse (Figure 2) and may be highly pungent and aromatic, with pungency being persistent when consumed. Habanero has one of the hottest chilli accessions in the world (Bosland, 1996). This species prefers high humidity conditions and are generally slower growers with longer growing seasons compared to many other species and possess seeds that take long to germinate (McMullan & Livsey, 2007).

A B C

Figure 2. Distinguishing characteristics of Capsicum chinense; green corolla and blue anthers (A), a variety of fruit shapes and colours (B & C).

Capsicum frutescens, like C. annum, is more adapted in humid lowlands (Pickersgill, 1997) and also originated from the Amazonia (Hundal & Dhall, 2005). The two major C. frutescens cultivars are tabasco and malagueta with former being the most popular and whose red fruit is

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the ingredient in Tabasco sauce. The other variety, malagueta is common in Brazil and is not related to the malagueta or Guinea pepper (Aframomum melegueta) from Africa that is related to ginger (Bosland, 1996). In Uganda, the commonest cultivar belonging to this species is the bird eye chili. Capsicum frutescens plants are characterized by a compact habit, numerous stems and ability to attain a height of 1-4 feet (Figure 3). The corolla of the flower is greenish white without spots and the anthers are purple. There is less variation among the pod types and are usually small, pointy and grow erect on the plants and a single plant can yield 100 or more pods (McMullan & Livsey, 2007).

A B C

Figure 3. Distinguishing characteristics of Capsicum frutescens; greenish white corolla without spots and the anthers are purple (A), numerous small pointed fruits (B) and compact plant growth habit (C).

Capsicum baccatum is most popular in South America and is also called aji. Capsicum baccatum var. baccatum, C. baccatum var. pendulum and C. baccatum var. microcarpum are the three recognized varieties of this species. The flowers have yellow, brown, or dark green spots on the corolla (Figure 4). The pungency of the fruits varies from non-pungent to very hot and also comprise distinctly unique aromatics (Bosland, 1996; McMullan & Livsey, 2007).

A B C

Figure 4. Distinguishing feature of Capsicum baccatum; yellow spots on the corolla (A)

Capsicum pubescens; Pubescens means 'hairy', a characteristic of Capsicum pubescens which is the least cultivated and has no wild form though it seems to share a close relationship with 7

two wild species; 'Cardenasii' and 'Eximium'. The species exhibits a compact to erect habit with a height ranging from 2-8 feet. The corollas are purple while the anthers are purple and white. The flowers stand erect from the leaves and the pods are either pear or apple shaped (Figure 5). In addition, the leaf pubescence is conspicuous and seeds are black (Bosland, 1996; McMullan & Livsey, 2007).

A B C

Figure 5. Distinguishing features of characteristics of Capsicum pubescens; purple corolla and purple and white anthers (A), pear or apple shaped fruits (B) and black seeds (C). (Source: Wikipedia, 2018)

2.2 Chemical and nutritional composition of hot pepper Hot pepper contains biologically active compounds such as carotenoids, capsaicinoids, fatty oils, steam-volatile oil, resin, protein, fibre, vitamins and mineral elements that are of importance in regards to nutrition, taste, colour and aroma. The most vital compound is vitamin C which the fruits contain in large quantities (Zachariah & Gobinath, 2008; Buczkowska & Labuda, 2015). Hot pepper is also rich in vitamin A and beta-carotene (Pawar et al., 2011).

Pungency is a typical attribute of hot pepper and is considered as one of its most important traits. This attribute is desirable in several foods especially in the insipid kind (Zewdie & Bosland, 2000; Bosland, 1996). Pungency of capsicum species is due to the presence of phytochemicals called capsaicinoids and which are unique to Capsicum species (Barbero et al., 2016; Palevitch & Craker, 1995). The capsaicinoids include capsaicin, dihydrocapsaicin, norcapsaicin, nordihydrocapsaicin, nornordihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin (Zewdie & Bosland, 2001; Bosland, 1996).

Pungency is measured in Scoville Heat Units (SHU). The Scoville Organoleptic Test was the first reliable measurement of pungency but due its limitations, has been supplanted by instrumental methods such as high-performance liquid chromatography (HPLC) (Scoville, 8

1912; Bosland, 1996). Capsaicinoid content in hot pepper ranges from zero to more than 300,000 SHU and is influenced by genotype and environment (Zewdie & Bosland, 2000; Bosland, 1996).

Colour, an important trait of capsicum, is determined by pigments called carotenoids. Carotenoid compounds are yellow to red pigments of aliphatic or alicyclic structures composed of isoprene units, which are normally fat-soluble colours (Bosland, 1996; Zachariah & Gobinath, 2008). The caretonoids specific to Capsicum are keto-carotenoids, capsanthin, capsorubin and cryptocapsin. Capsanthin and capsorubin determine the red colour in chilli while the yellow-orange colour is from β-carotene and violaxanthin. The major carotenoid in ripe fruits, capsanthin, constitutes up to 60% of the total carotenoids (Bosland, 1996; Palevitch & Craker, 1995; Zachariah & Gobinath, 2008).

2.3 Ecological and agronomic requirements of hot pepper Hot pepper requires optimum day temperatures ranging from 20-30°C and night temperatures below 24°C. Growth and yield diminish with prolonged periods of temperatures below 15°C and above 32°C. Though hot pepper can be grown on a wide range of well-drained soil types, deep medium textured loam or silt loam with good water-holding capacity is preferable. Soil pH ranging from 5.5 and 6.8 is ideal for hot pepper growth (Berke et al., 2005; Kelley & Boyhan, 2009). In rain fed conditions, the crop requires at least three months of rainfall. Insufficient rainfall causes bud and flower abscission, however, with heavy rains and very high humidity, mold growth and fruit rot increases (Amati et al., 2002).

The major abiotic stresses hampering hot pepper production are caused by temperature, moisture, salinity and nutrient factors. Suitable temperature for hot pepper germination and growth ranges from 20-30°C. Temperatures exceeding 35°C reduce germination capacity and subsequently low yields and poor quality fruits. High temperatures like heavy rainfall, cause bud and flower abscission. Light and temperature are known to affect germination of hot pepper though the effect of light is much more dependent on the temperature and the type of genotype (Kelly & Boyhan, 2009).

Inadequacy of major nutrients such as nitrogen also stresses hot pepper plants. When these nutrients are supplied in ample quantities through fertilizer and organic matter applications, deficiency effects can be eschewed. The abiotic constraints can also be offset by use of adaptable genotypes to a particular area. More still, irrigation, nutrient supply, timely planting

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and application of soil amendments to correct pH extremes are useful counteractions (McDougall et al., 2013).

Hot pepper is prone to diseases and pests which are the primary causes of crop losses in the tropics (AVRDC, 2008). The damage and the losses inflicted by diseases and pests are so profound that their management takes a considerable share of production costs (Bosland & Votava, 2000; Karungi et al., 2011). In Uganda, insect pests such aphids (Aphis gossypi Glover, Myzus persicae Sulzer), whiteflies (Bemisia tabaci Gennadius) and thrips (Thrips tabaci Lindeman, Scirtothrips spp., Ceratothrips spp., Frankliniella occidentalis Pergande and Megalurothrips sjostedti Trybom), tomato fruit worm (Helicoverpa armigera) and fruit flies (Ceratitis capitata; Bactrocera spp) are important pests of hot pepper. Other pests include broad mites (Polyphagotarsonemus latus) and root-knot nematodes (Meloidogyne spp.) (AVRDC, 2010; Hasyim et al., 2014; Muzira, 2015). Of recent, the invasive false coddling moth has been reported in the country and has brought serious repercussions as a quarantine pest of hot pepper (Besigye, 2015). Other than the direct damage these insect pests inflict on the crop, some (aphids, white flies and thrips) are vectors for viral diseases (Black et al., 1991; Agrios, 2005; McDougall et al., 2013).

2.4 Quarantine pests of hot pepper

Fruit flies (Diptera: Tephritidae) Fruit flies belong to the order Diptera and family Tetriphidae. There are more than 4000 species of fruit flies widely distributed in the tropics, subtropics and temperate regions of the world (Christenson & Foote, 1960). The most important ravaging fruit fly genera in Africa include; Bactrocera, Capparimyia, Ceratitis, Dacus, Neoceratitis, Trirhithrum and Zeugodacus (Virgilio, 2016). Though more than 400 species are reported to be existent in Africa, only more than 50 species are of economic importance (Virgilio et al., 2014). In Uganda, the commonest species are Ceratitis spp, Bactrocera, Dacus spp and Trirhithrum spp (Nankinga et al., 2014).

2.4.1.1 Description and biology of fruit flies Tetriphid flies have a holometabolous kind of lifecycle consisting of four life stages; egg, larvae, pupa and adult. The adult female oviposits underneath the skin of the fruit and the oviposition sites appear often as black-spotted marks. Eggs may take 3-12 days to hatch into white larvae depending of the prevailing temperature. The larval stage has three distinct instars that tunnel the fruit while feeding and this stage lasts for 7-9 days. The feeding usually results

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in rotting of the infested fruit. The third larval instar leaves the fruit by its distinct jumping motion to the soil where it pupates and eclosion occurs. Both larval and pupa stages may take between 10-20 days while eclosion, 10-11 days. The adult fruit flies only become sexually mature in 4-10 days after emergence (Ekesi & Billah, 2007).

2.4.1.2 Host range, damage and economic importance of fruit flies Most of the fruit flies of economic importance are polyphagous (Virgilio, 2016) and pause serious control and management implications. In Uganda, crops such tomatoes, hot pepper, mangoes, water melons, coffee, paw paws among others are hosts of fruit flies (Nankinga et al., 2014). Muzira (2015) reported Ceratitis capitata as the most prevalent and important frugivorous species in hot pepper.

Direct damage by fruit flies during oviposition and by the larva promotes infection by opportunistic bacteria and hence fruit rot. Tephritid flies can cause substantial losses in both fruit yield and quality of up to 100% if control measures are not employed (Kakar et al., 2014). Indirect damage is usually felt at the international market, where stringent quarantine laws have been enacted to block the entry of fruit fly species into importing countries. Infested fruit consignments are intercepted resulting in rejection of the export crop produce (Tanga & Rwomushana, 2016; Badii et al., 2015). This reduces revenue from exports and consequently small-scale farmers’ income. Hence control of the flies is very crucial, if the market is to remain accessible and the trade lucrative.

2.4.1.3 Management of fruit flies Cultural practices with emphasis on crop field sanitation are employed in the management of fruit flies. Fallen or infested fruits are picked and buried to destroy the larvae. It is more effective if done more than once in a week though weekly routines offer substantial control. Bagging of infested fruits before the emergence of adult flies also reduces fruit fly infestation (Isabirye et al., 2016). These methods are more practical with small crop fields or orchards but with vast fields, labour costs may rise.

Fruit fly traps, employed in Male Annihilation Technique (MAT) and Bait Annihilation Technique (BAT) have proved effective in Uganda. MAT uses a pheromone, usually methyl eugenol while BAT uses a protein and sugar. The pheromone and sugar act as attractants for flies to the traps which are equipped with a pesticide that kills them (Isabirye et al., 2016).

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Use of pesticides is the major practice used for managing most horticultural crop pests, including fruit flies. Though this method is quick, pesticide resistance and health hazards to farmers and consumers have been associated with it. More still, overdependence and inappropriate use of the chemicals, increase the likelihood of failure to meet the acceptable maximum residual levels in export produce (Karungi et al., 2013). Hence, judicious use of these agro-inputs is necessary in order to preserve the profitable fruit trade.

Post-harvest cold and heat treatments are available for management of fruit flies. Cold or low heat treatment have been used successfully for citrus and avocado. This method when prolonged or done at very low temperature, damages the fruits. On other hand, heat treatment is more acceptable for tropical fruits such as mangoes because it is quick and the most fruits can withstand the heat (Grout, 2016).

Biological control involves use of natural enemies; predators and parasitoids, to lower pest populations. Generalist predators such carabid beetles, assassin bugs and spiders have been reported to feed on fruit fly larvae. Parasitoids including Fopius arisanus and Diachasmimorpha longicaudata, lay eggs in the eggs or larvae of their hosts (fruit flies). These hatch and feed on the larvae to complete their life cycle and hence killing the host (Sarwar, 2015). Control of tetriphid flies using parasitoids Doryctobracon areolatus and Utetes anastrephae is exploited in Brazil (Uchoa, 2012). Natural enemies are usually slow in action and are disrupted by the use pesticides.

Though several measures are in place to counteract fruit fly losses, none of them is self- sufficient. Thus integrated pest management is essential to ensure a sustainable lucrative horticultural business. Being a central part of IPM, host plant resistance when exploited will yield eco-safety and cost friendliness to hot pepper production. Host plant resistance has not been assessed and utilized for hot pepper in Uganda.

The false codling moth (Thaumatotibia leucotreta (Meyrick)) The false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) occurs naturally in South Africa, Sub-Saharan Africa and Indian Ocean Islands (Malan et al., 2011). It has wide host range including citrus, macadamia, guavas, cotton, maize, pear oranges, and peppers. It is economically important in the horticulture sector; especially in South Africa because of the losses, it incurs the citrus industry (de Jager, 2013; EPPO, 2013). It has gained popular status of recent in hot pepper production sector as a quarantine pest (EPPO, 2013;

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Besigye, 2015). A remarkable decrease in hot pepper export volumes from Uganda between 2014 and 2015 was a result of the FCM invasion and the failure to comply to the maximum residual levels of pesticides. Consequently, key stakeholders in the export industry imposed a ban on the exportation of the crop (Besigye, 2015). More still, there have been over 200 interceptions of hot pepper exports due to the pest between January 2015 and October 2017 at the international market (MAAIF, n.d). Thus, the false codling moth is continuing to negatively affect the profitability of the hot pepper trade.

2.4.2.1 Description and biology of the false coddling moth The moth has a complete lifecycle lasting for 30-174 days depending on the prevailing conditions. Since the FCM does not undergo diapause, it remains active throughout the year given the right host and can have up to five generations. The females are usually more than the males at the ratio of 2:1 and even tend to live longer (Stibick et al., 2010; de Jager, 2013).

The moths lay their eggs on the rind of the fruit, leaves, smooth or non-pubescent surfaces of the plant. The eggs are yellowish usually 1mm long, small, ovoid and fattened. These become translucent in colour towards hatching. The number of eggs laid ranges from 3-8 and the female may lay 800 eggs during her lifetime though only a few survive. The eggs take 2-22 days to hatch into larvae which then penetrate the fruit through the rind leaving behind burrows (1mm diameter). The site of their entry is evidenced by frass on the surface and discolouration of the rind (Stibick et al., 2010; de Jager, 2013; Ostojá-Starzewski et al., 2017).

Usually a single larva is found per fruit but a maximum of three larvae have been recorded. The larvae range from 12-20mm in length with a distinct brown or black head. Their colour may range from cream or pale to pink or reddish depending on the stage of maturity. There are five larval instars and the stage lasts for 12-67 days. The young larvae feed near the fruit surface but the mature larvae feed towards the center resulting in premature fruit drop (Malan et al., 2011; de Jager, 2013; Ostojá-Starzewski et al., 2017). If it happens that the fruit remains on the branch, the last instar-larva drop to the ground with aid of a silken thread (de Jager, 2013). They then bury themselves under the soil a few millimeters, and spin tightly woven cocoons. The prepupa in the cocoon becomes a pupa after 2-3 days. The adult moths eclose 12–16 days at 25◦C but take longer at lower temperatures (Malan et al., 2011). The moths are small and black to brown in colour, 7-8mm in length with a 15-20mm wing span (Ostojá-Starzewski et al., 2017).

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2.4.2.2 Host range, damage and economic importance of the false coddling moth The false coddling moth is of great economic importance because of its status as a quarantine pest (EPPO, 2013; Besigye, 2015). It has been reported that it has a wide host range including citrus, macadamia, guavas, cotton, maize, pear oranges, and peppers (de Jager, 2013; EPPO, 2013). The FCM directly reduces the marketable yield by boring the fruit. Damage is difficult to detect externally on fruits but can clearly be assessed when fruits are opened. The infested fruits are characterized by tunnels and frass resulting from feeding activities of the larva once inside the fruit. Nevertheless, minute brown marks appear as the proof of entry by FCM larva. Though difficult to detect, the marks may become more pronounced with time as recessed brown or yellow spots on the skin (Venette et al., 2003; Stotter, 2009) but are not necessarily easy to see (Ostojá-Starzewski et al., 2017). The infested fruits may prematurely drop from the plant (Venette et al., 2003) and where the fruit remains attached, it becomes misshaped before ripening (MANFQ, 2009).

2.4.2.3 Management of the false coddling moth Cultural efforts, especially crop field sanitation which involves removal and destruction of infested fruits from the field have been maintained for long. Infested fruits are destroyed using fire, by burying or by using plastic bags to prevent larval development. Though field sanitation is considered greatly effective in the management of the FCM, it demands immense labour (Stotter, 2009).

Despite the availability of pesticides, control of the FCM is hampered by development of resistance, resurgence and secondary pests. In addition to these, the pesticides tend to be indiscriminative, and hence kill natural enemies of the pest as well (Mazid et al., 2011). In Uganda, the risk of rejection of the hot pepper export on the international market is escalated by over dependence on synthetic pesticides to control the pest (UIA, 2009).

Biological control using natural enemies (parasitoids and predators) has been used against the pest in citrus orchards with some success. The most important parasitoids in control of FCM in the citrus industry of South Africa are egg parasitoids, Trichogrammatoidea cryptophlebiae (Nagaraja) (Moore, 2002; Stotter, 2009). Granuloviruses (Cryptophlebia leucotreta granulovirus) which utilizes a natural virus has also registered some substantial control of the pest. The granulovirus is sprayed on leaves and fruits and is consequently absorbed by larva on eclosion. The larvae are killed by the virus and vast amounts of viral particles get discharged into the surrounding and hence perpetuating the viral cycle (Moore, 2002; Stotter, 2009). This 14

method requires other control measures to be in place before it can be applied if considerable loss reductions are to be achieved (Stotter, 2009).

Other control practices include use of mating disruption and sterile insect techniques. The former technique involves using a sex pheromone that hinders the males from locating females as well as limiting the number of viable eggs laid in fruits. The sterile insect technique on the other hand involves use of an attractant (pheromone) and an insecticide to attract and kill males. This technique has shortcomings such as being only more effective in low FCM infestations and it is detrimental to bees (Moore, 2002; Stotter, 2009).

Despite all these measures in place, the FCM predicament is ongoing. Moreover, these measures are used mainly in citrus production and their impact on loss reduction in hot pepper is not known. Therefore, appropriate and cost effective FCM management measures are essential if the hot pepper venture is to remain lucrative to the small-scale growers and the Republic of Uganda as a whole.

2.5 Capsicum diversity for improving hot pepper resistance to pest infestation Opportunities of improving cultivated species of Capsicum are vast through plant breeding due to the wide genetic diversity (Pickersgill, 1997; Fernie et al., 2006; Costa et al., 2006). With this diversity, superior genotypes to those available in regards to characters of interest such as pungency, fruit size, colour, and quality, vitamin C content, and resistance to pests and diseases can be bred (Sood & Kumar, 2011; Teodoro, et al., 2013). The diversity in hot pepper germplasm allows for identification and, breeding for pest resistant varieties and improvement of the crop.

Host plant resistance is a fundamental component of integrated pest management. It is the inherited ability of a plant to minimize the effects of pest attack. It is as a result of inherent plant physiological, chemical and behavioural properties that enable the plant to evade or reduce insect attack and or utilization. Host plant resistance is valued for it eco-friendliness, low production costs and human health safety (Pedigo & Rice, 2014). Varying levels of susceptibility to fruit flies have been observed in tomatoes (Balagawi et al., 2005), bitter gourd (Nath et al., 2017) and in mangoes (Nankinga et al., 2014) among others. Among citrus varieties, Fischer Navels are less susceptible to the false codling moth than other varieties such as Palmer Navels (Love et al., 2014). Similarly, lemon has also been reported to be resistant to FCM (Moore et al., 2015).

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There are three major mechanisms of resistance to phyto-pests; antibiosis, antixenosis and tolerance. Much of the research is directed towards the first two. Antibiosis is characterized by chemical substances or allellochemics that kill, reduce growth and development of insect pest larvae or pupae. Shortened insect lifecycles is also associated with antibiosis. Plant allellochemics include phenols, ascorbic acids, protein content, flavonoids and silica among others (Pedigo & Rice, 2014). Nath et al. (2017) screened 74 bitter gourd genotypes for resistance to Bactrocera cucurbitae and reported a significant correlation between ascorbic acid content and fruit fly infestation. In a study by Love et al. (2014), citrus genotypes such as Fischer Navel with a high brix/acid ratio seemed to have a lower susceptibility to FCM. This mechanism of resistance is the most sought out for in most breeding programs.

Antixenosis on the other hand, involves deterrence of insects from oviposition and utilization of the host because it is unfavourable. “Hence the term bad host”. This mechanism is conferred by morphological and allellochemic attributes of the host and alters the pest behavior to the host. Tolerance refers to the ability of the plant to recover from pest damage or compensate for the losses due to pest attack in comparison to the susceptible host. The important fruit traits that influence fruit fly oviposition and utilization for food have been studied in many crops (Pedigo & Rice, 2014). These characteristics include colour, shape, size, pericarp toughness or firmness, ripeness and fruit wall thickness. Host quality is crucial since it relates to larval performance and consequently to that of adult (Balagawi et al., 2005).

2.5.1 Morphological and biochemical traits influencing fruit pest infestation and utilization

2.5.1.1 Host colour Colour is a vital aspect in host selection for oviposition by adult pests. Different fruit fly species are more attracted to some colours than others. Pinero et al. (2006) reported that Bactrocera cucurbitae (Coquillett) females were attracted mainly to yellow, white and or orange colours. Drew et al. (2003), portrayed from their experiments that Bactrocera tryoni (Froggatt) preferred blue and white colours while B. cacuminata, yellow or orange. Searching for a suitable host is therefore facilitated by fruit colour. Despite this fact, it is important to understand that fruit colour alone is not sufficient for successful host location. But olfactory cues emitted by host plants enable the flies to locate them, and then colour cues come into play latter (Pinero et al., 2006; Brevault & Quilici, 2007). Brevault & Quilici, (2010), reported fruit odour is useful during scarcity of hosts (fruits) or when, fruits are shrouded by the canopy while 16

visual cues are crucial in case the fly loses olfactory cue trails. It seems that colour has little or no effect at all on oviposition preference or host utilization by the FCM. A study by Moore et al. (2015) showed that all lemon fruits belonging to the different export colour grades for lemon were without oviposition or larva of the pest.

2.5.1.2 Olfactory cues Volatile secretions emitted by the host plants are not only essential in host finding (Brevault & Quilici, 2007) but also in ascertaining suitability of the host for oviposition by adult female fruit flies (Balagawi, 2006). These cues vary among host species and significantly impact host preference by the flies (Cornelius et al., 2000). Fruit fly species, polyphagous in nature are attracted by many host odours. Anastrepha striata Schiner was found to be attracted by seven compounds from ripe oranges (Citrus sinensis L.) and guavas (Psidium guajava L.). One compound was from the oranges and the rest from the guava (Diaz-Santiz et al., 2015). This probably explains why most of the economically important fruit fly species can survive in absence of their preferred host.

2.5.1.3 Ripeness of the fruit The stage of fruit ripeness highly influences oviposition and utilization by frugivorous fruit flies. Ripe fruits are preferred to unripe fruits by many fly species (Alagarmalai et al. 2009; Rattanapun et al., 2009). This is because ripe fruits emit volatile cues that attract tetriphid fruit flies for oviposition and utilization. Hence, they can easily be located. Ripe fruits are also softer than unripe fruits and thus easier to oviposit in. Rattanapun et al. (2009) reported that Bactrocera dorsalis, known to oviposit in unripe fruits also preferred ripe and fully ripe mango fruits when available. More still, larval performance was highest in ripe and fully ripe fruits.

Despite, FCM having the ability to infest immature fruits, de Jager (2013), reported FCM preference for citrus and plum fruits increased with ripening. Thus, control measures ought to be fortified close to the fruit ripening stage.

2.5.1.4 Fruit size and shape Research findings ascertain that size and shape are crucial factors in host finding, utilization and consequently larval performance (Dhillon et al., 2005; Brevault & Quilici, 2007; Aluja & Mangan, 2008). Fruit size is a visual cue that is important for host location but may not necessarily account for utilization (Prokopy, 1977). Brevault & Quilici (2009) reported that

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Neoceratitis cyanescens (Bezzi) preferred to oviposit in small green tomato fruits to larger ripe fruits.

The shape of the fruit also attracts tetriphid flies to their hosts. Pinero et al. (2006) showed that Bactrocera cucurbitae (Coquillett) were more attracted to spherical shapes more than cylindrical fruit mimics. Similarly, Bactrocera minax (Enderlein) preferred spheres to discs (Drew et al., 2006). Therefore, fruits that tend to be spherical in form are likely to have more fruit fly attacks.

2.5.1.5 Fruit firmness and toughness Fruit toughness influences host range and oviposition in fruit flies (Balagawi et al., 2005; Rattanapun et al., 2009; Gogi et al., 2010). The tougher the fruit flesh, the less likely the fruit will be preferred for oviposition. Balagawi et al. (2005) reported that reduced infestation of cherry tomato was based on its pericarp toughness. Fruit penetrability increases with ripening (Rattanapun et al., 2010) and hence could also supplement on why most fruit fly species prefer ripe to unripe fruits. Dhillon et al. (2005) reported a significant negative correlation between bitter gourd pericarp thickness and fruit fly infestation. There are studies that prove existence of exceptions. Wingsanoi et al. (2013) reported that fruit traits including pericarp thickness of different pepper varieties did not influence fruit fly infestation. Nufio et al. (2000) also reported that fruit toughness did not influence walnut fruit infestation by Rhagoletis juglandis.

Love et al. (2014), reported that differences in the levels of susceptibility of citrus varieties to FCM could be accredited to peel mass. The peel mass of Fischer Navel citruses conferred them resistance by making the peel harder to penetrate. However, the findings of Albertyn (2017) were in contradiction. The rind masses and rind thickness instead increased the susceptibility of citrus varieties to the FCM. He attributed this to the high nutrient quality of thicker peels. Thus the potential of fruit wall thickness in susceptibility to FCM is not yet clear especially for citrus. Perhaps, in hot pepper it could play a positive role in resistance to the pest.

This study therefore aimed at determining resistant hot pepper genotypes to the frugivorous pests and the fruit traits associated to the susceptibility of the genotypes to the pests.

2.6 Relationship between fruit traits and yield of hot pepper

Yield is one of the most important factor considered in crop breeding programs. With the rich diversity of hot pepper, much variation is expected in yield potential of the different cultivars

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and landraces. There are plant factors that contribute to yield and these include; growth and fruit traits. Fruit traits that have been reported to influence yield of hot pepper include; number of fruits per plant, fruit weight, width and length (Chakrabarty & Islam, 2017; Soares et al., 2017). The relationships, usually correlations between these traits and yield are profound in crop improvement programs (Soares et al., 2017). This study also aimed at assessing the relationships of fruits of different hot pepper genotypes that profoundly influence yield so as to incorporate them in the local breeding programs for the crop.

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CHAPTER THREE

3.0 MATERIALS AND METHODS

3.1 Study site Hot pepper germplasm were screened under natural conditions for resistance to infestation by fruit flies and the false coddling moth (FCM) at Makerere University Research Institute Kabanyolo (MUARIK) in 2016 and 2017. MUARIK is located 19 km north of Kampala at 0º28’N, 32º27’E; and at an altitude of 1204m. The upland soils are deep, highly drained red soils that are classified as latisols. Soils have a pH of 5.6 (Karungi et al., 2006). The climate of this area is sub-humid with moderately well distributed bimodal rainfall of 1200mm per annum. The average annual minimum and maximum temperatures are 14°C and 28.5°C, respectively (Mibulo & Kiggundu, 2018). MUARIK is situated in Wakiso district whose average annual humidity level is 78.9% (Weather Atlas, n.d).

The evaluation hot pepper trial was also conducted on-farm in Ibanda district. Ibanda district has soils ranging from red sandy loam to reddish brown sandy loams with a warm tropical climate. The average annual minimum and maximum temperatures are 14°C and 28°C, respectively. The area has a bimodal rainfall pattern with total annual rainfall ranging between 1000mm and 1200mm (MEMD & REA, 2019). The area is also has a mean annual relative humidity of 74.5% (Weather Atlas, n.d).

3.2 Source of hot pepper germplasm and seedling raising A countrywide survey was conducted to collect germplasm from farmer fields and homestead gardens in major hot pepper growing districts including Kabale, Kisoro, Ntungamo, Kasese, Mbarara, Ibanda, Lira, Gulu, Kole, Mayuge, Buikwe and Mukono. This yielded 37 genotypes. Fourteen hot pepper varieties obtained through cooperation with Brazil (Embrapa) formed the exotic cohort of the germplasm collection. Tables 1a and 1b show the different exotic and local genotypes respectively and their sources, origin and types.

Seeds were sown in sterilized soil medium. Three weeks after which, single seedlings of each genotype were potted in polythene sleeves consisting of soil and compost in a ratio of 3:1. An organic fertilizer Vegimax (at a rate of 35mls/15l) was applied twice weekly for two weeks from potting. The seedlings were hardened at 6 weeks from sowing and transplanted to the field at 8 weeks.

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3.3 Study Design The field experimental design was a randomized complete block design. The 51 genotypes were the treatments, each planted in a single row replicated three times. Each row comprised 10 plants (experimental units) spaced at 45cm and 80cm between rows. The genotypes (treatments) were replicated in three blocks separated by 2m alleys. Guard rows of beans were planted around the experimental area. The on-station trial hot pepper genotype evaluation was conducted for two seasons. The first season (2017A) ran from December 2016 to June 2017. The second season (2018B) was conducted from September 2017 to March 2018 because three of the genotypes had a poor germination. The experiment was conducted under field conditions but watering was done when needed. Pesticides were not used and weeding was done with a hand hoe. Due to the low FCM infestation in MUARIK, 15 genotypes selected based on seed availability were further tested in a FCM hotspot (Ibanda district) with the same design from July 2017 to January 2018 (Season 2018C).

Data collection Data was collected from all the 10 plants of each genotype per plot (block). Ripe fruits were harvested for four consecutive times in season 2017A and six times in season 2018B and grouped as per genotype. Meanwhile, four harvests were done in the on-farm trial in season 2018C. The harvests of the hot pepper were done on a biweekly basis.

The fruits were weighed, inspected and graded into marketable and non-marketable fruits. Further grading was done on non-marketable fruits; fruits with oviposition marks and those rotting were considered damaged (modified from Nath et al., 2017). The external damage (oviposition and entry marks) of fruits by both fruit flies and FCM are similar and many marks were observed on the fruits. This made external differentiation of fruit pest damage difficult. Therefore, all fruits that had marks associated with oviposition or larval entry were considered damaged and their percentage proportion was calculated as;

푁푢푚푏푒푟 표푓 푑푎푚푎푔푒푑 푓푟푢𝑖푡푠 Damaged fruits (%) = 푋 100 푇표푡푎푙 푛푢푚푏푒푟 표푓 푓푟푢𝑖푡푠 The damaged fruits were further opened to reveal presence of internal damage and larva (Nath et al., 2017). The fruits that had fruit fly larva were considered infested and the number of larva recovered per fruit was recorded (Rossetto et al., 2006). The proportion of fruits infested by fruit flies was calculated as shown in Eqn 1 below.

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푁푢푚푏푒푟 표푓 푓푟푢𝑖푡푠 푤𝑖푡ℎ 푓푟푢𝑖푡 푓푙푦 푙푎푟푣푎 Fruit fly infestation (%) = 푋 100 … … … . Eqn 1 퐷푎푚푎푔푒푑 푓푟푢𝑖푡푠

Internal fruit damage by FCM is distinct from that of fruit flies; the FCM usually leave frass during feeding (Ostojá-Starzewskiet al., 2017). It was on the basis of this kind of damage and presence of FCM larvae that the fruits were considered infested by FCM (Eqn 2).

푁푢푚푏푒푟 표푓 푓푟푢𝑖푡푠 푤𝑖푡ℎ 푓푟푎푠푠 표푟 푙푎푟푣푎 FCM infestation (%) = 푋 100 … … … … . … Eqn 2 퐷푎푚푎푔푒푑 푓푟푢𝑖푡푠

Yield (t/ha) was obtained per genotype per plot from total fruit weight of total number fruits harvested per plot for each season. Marketable yield was computed from marketable fruit weight and the number of marketable fruits.

Average fruit weight, length (from the pedicel attachment to bottom tip of the fruit), width (from the widest points of the fruit), fruit wall thickness (from the point of maximum width) and penetration force were measured from 10 randomly selected fruits per genotype per plot in the second harvest. Marketable, and non-marketable fruits and average fruit weight were weighed using an electronic weighing scale. Fruit length, width and thickness were measured using a digital caliper following the standard Capsicum descriptors (IPGRI et al., 1995).

Fruit penetration force required to penetrate the fruit was taken from three points along the fruit center with force gauge (Ametek, Mansfield & Green products, Somerset Drive, USA) using the 1mm pin. The readings were recorded in kg but later converted to newton (N). The average gauge readings for the three points were calculated and used in analysis.

Data analysis The general linear model of Genstat analysis software package (12th edition, version 2; VSN International Ltd, 2010) was used to generate analysis of variance (ANOVA) with 2017And hot pepper genotypes as fixed factors and pepper types (Capsicum species) as a covariate. Response variables included pests’, fruit and yield parameters. Data were checked for normality using the Shapiro-Wilk test and transformed where necessary. Arcsine transformation was used for percentage pest infestations while the square root transformation (√(X+1)) for pest counts. Where the ANOVA gave significant results, means (of pest

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infestation, yield and fruit quality traits) were separated by Fisher’s protected least significance difference test at 5%. Correlation analysis was conducted on pest infestation parameters, and fruit quality traits and yield to establish the existent relationships.

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Table 1a. Exotic germplasm, source/origin, type, fruit characteristics Germplasm code Source/origin Type Fruit shape Mature fruit colour NSR0105-01 USA Habanero Blocky Red NSR0105-02 USA Habanero Blocky Orange BRS-M205-03 Brazil Calabrian Elongate Red BRS-M205-04 Brazil Biquinho Almost round Red OHA0306-05 Mexico Habanero Campanulate Orange HAP-W305-06 USA Habanero Campanulate Orange RHA-T305-07 USA Habanero Campanulate Red OHA-C309-08 USA Habanero Campanulate Orange OHA-T305-09 USA Habanero Campanulate Orange OHA-B305-10 USA Habanero Campanulate Orange RHA0307-11 USA Habanero Campanulate Red CAP0408-12 China Cayenne Elongate Red PBA-CPT-10 Brazil De cheiro Elongate Yellow PDC-CPT-11 Brazil Biquinho Almost round Yellow

Table 1b. Local germplasm, and their collection site and types Germplasm code Collection site Type Fruit shape Mature fruit colour UG-CE01-0401 Mukono Habanero Campanulate Red UG-WE02-1802 Ntungamo Habanero Campanulate Yellow UG-WE03-0503 Kisoro Scotch bonnet Blocky Orange UG-NO04-2004 Omoro Bird eye chili Elongate Red UG-CE01-0805 Mukono Habanero Campanulate Yellow UG-NO07-0606 Kole Bird eye chili Elongate Red UG-WE05-0607 Mbarara Scotch bonnet Blocky Red UG-WE02-1608 Ntungamo Cayenne Elongate Red UG-WE02-1909 Ntungamo Habanero Campanulate Red UG-WE02-0711 Ntungamo Bullet chili Triangular Red UG-WE02-0513 Ntungamo Habanero Campanulate Yellow UG-WE02-1014 Ntungamo Cayenne Elongate Red UG-EA06-0515 Mayuge Bird eye chili Elongate Red UG2-WE0106-01 Kisoro Cayenne Elongate Red UG2-WE0102-02 Kisoro Bullet chili Elongate Red UG2-WE0119-03 Kisoro Habanero Campanulate Red UG2-WE0103-05 Kisoro Bullet chili Triangular Red UG2-NO0210-06 Gulu Bird eye chili Elongate Red UG2-NO0214-07 Gulu Bird eye chili Elongate Red UG2-NO0215-08 Gulu Bird eye chili Elongate Red UG2-NO0211-09 Gulu Bullet chili Elongate Red UG2-NO0211-10 Gulu Bird eye chili Elongate Red UG2-NO0217-11 Gulu Bird eye chili Elongate Red UG2-NO0212-12 Gulu Bird eye chili Elongate Red UG2-NO0203-13 Gulu Bird eye chili Elongate Red UG2-WE0307-14 Ibanda Bird eye chili Elongate Red UG2-WE0318-15 Ibanda Habanero Campanulate Red UG2-WE0402-16 Kasese Bird eye chili Elongate Red UG2-WE0419-17 Kasese Scotch bonnet Blocky Red UG2-WE0405-18 Kasese Bird eye chili Elongate Red UG2-WE0502-20 Kabale Bird eye chili Elongate Red UG2-WE0507-21 Kabale Serrano Elongate Yellow UG2-WE0511-22 Kabale Bird eye chili Elongate Yellow UG2-WE0505-23 Kabale Bullet chili Elongate Red UG2-EA0604-24 Buikwe Cayenne Elongate Red UG2-CE0706-25 Mukono Scotch bonnet Blocky Red UG2-WE0808-26 Ntungamo Unidentified Elongate Orange

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CHAPTER FOUR

4.0 RESULTS AND DISCUSSIONS

4.1 EFFECT OF HOT PEPPER GENOTYPES ON FRUIT PEST INFESTATION

4.1.1 Effect of hot pepper genotypes and seasons on fruit damage The percentage number of fruits damaged differed highly and significantly (P<.001) among hot pepper genotypes evaluated at MUARIK but was not significantly different between seasons. Hot pepper genotypes interacted significantly with 2017At P<.001. Genotypes had a mean of 48.0% of damaged fruits in season 2017A and 48.3% in season 2018B. Genotypes PDC-CPT-11 (70.6%) and BRS-M205-04 (67.6%) had the highest percentage of damaged fruits in 2017A. Genotypes, CAP0408-12 (4.9%) and UG-WE02-1014 (0.7%) registered the lowest damage. For season 2018B, genotypes UG2-WE0808-26 (91.8%) and UG-WE02-1909 (89.3%) had the highest damage, while CAP0408-12 (16.1%) and UG-WE02-0711 (15.5%) registered the lowest damage (Table 2).

The number of damaged fruits differed highly and significantly (P<.001) among hot pepper genotypes evaluated on the farmer-field in season 2018C. Genotypes RHA0307-11 (71.5%), UG-WE02-0513 (71.4%), and RHA-T305-07 (71.2%) had the highest percentage of damaged fruits. Conversely, genotypes CAP0408-12 (1.2%) and UG-WE02-1608 (6.3%) had the lowest percentages of damaged fruits (Table 3).

4.1.2 Effect of hot pepper genotypes and seasons on fruit fly infestation and fruit fly larva per fruit There was a highly significant difference (P<.001) in fruit fly infestation among the genotypes and between seasons (P<.001) (Table 2). Genotypes in season 2017A had a higher mean number of infested fruit (20.1%) in contrast to when in 2018B (7.6%). Genotypes NSR0105- 01 (46.3%) and UG2-WE0419-17 (42.5%) had the highest mean infestations while UG2- WE0402-16 (2.4%) and UG2-WE0307-14 (1.3%) had the lowest in season 2017A. In season 2018B, genotypes UG-WE02-1909 (25.8%) and UG2-WE0318-15 (23.5%) had the highest mean infestation whereas genotypes RHA0307-11, UG2-NO0211-10, UG2-NO0217-11, UG2-WE0307-14, UG2-WE0507-21, UG2-WE0511-22 and UG2-EA0604-24 had no infestation.

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Similarly fruit fly infestation varied significantly (at P<.001) among hot pepper genotypes evaluated on farmer-field (Table 3). The genotypes RHA0307-11 and OHA-B305-10 had the highest fruit fly infestation at 26.6% and 26.3%, respectively. In contrast, genotypes UG- WE02-1608 and CAP0408-12 had no fruit fly infestation (0.0%) throughout the evaluation period.

The mean number of fruit fly larvae per fruit varied highly and significantly (P<.001) among hot pepper genotypes and between seasons (P<.001). Genotypes had a higher mean number of larvae per fruit (1.7) in season 2017A than in season 2018B (0.9). Genotypes, PBA-CPT-10 (3.1), NSR0105-01 and UG-WE02-0711 (3.0) had the highest mean numbers of larvae per fruit in 2017A, while UG2-WE0511-22 (0.8) and UG-WE02-1014 (0.0) had the lowest means. Similarly, in season 2018B, the number of fruit fly larvae per fruit differed significantly among genotypes (P = 0.001). Generally, the mean number of larvae per fruit among genotypes in season 2017A decreased by 46%. Genotypes NSR0105-02 (2.7) and RHA-T305-07 (2.5) had the highest numbers of larvae per fruit while UG2-EA0604-24, UG2-NO0211-10, UG2- NO0217-11, UG2-WE0307-14, UG2-WE0507-21 and UG2-WE0511-22 (0.0) had no fruits with larvae (Table 2).

The mean number of larvae per fruit also varied significantly (P<.001) among hot pepper genotypes evaluated on the farmer-field. The mean number of larvae per fruit varied from 0.0 to 2.6 and genotypes UG-WE02-1909 and UG-CE01-0401 had the highest mean number of fruit fly larvae per fruit, 2.6 and 2.4, respectively. Both genotypes UG-WE02-1608 and CAP0408-12 registered the lowest mean number of fruit fly larvae per fruit (0.0) (Table 3).

4.1.3 Effect of hot pepper genotypes on false coddling moth infestation Fruit infestation by the false coddling moth (FCM) larvae was generally very low (Table 2) but significantly different across seasons (P<.001). The fruit infestation by FCM among hot pepper genotypes varied significantly in season 2017A (P<.001) but not in season 2018B. The highest mean fruit infestation by FCM (0.5%) was registered in season 2017A and almost 50% of the genotypes had infestations. Genotypes NSR0105-01 (2.0%) and NSR0105-02 (1.9%) had the highest infestation while UG2-NO0211-09 and OHA-T305-09 (0.1%), the lowest. Surprisingly, only genotype OHA-T305-09 was infested by FCM in season 2018B. Similarly, fruit infestation by the FCM among hot pepper genotypes evaluated on the farmer-field was low and did not vary significantly among the genotypes (Table 3).

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Table 2. Damage and infestation by fruit pests of hot pepper genotypes evaluated in MUARIK, Uganda in seasons 2017A and 2018B Fruit fly infestation Mean number of False codling moth Damaged fruits (%) Genotype (%) larvae per fruit infestation (%) 2017A 2018B 2017A 2018B 2017A 2018B 2017A 2018B NSR0105-01 56.4 54.1 46.3 12.7 3.0 1.3 1.9 0.0 NSR0105-02 62.7 62.5 31.9 11.1 1.7 2.7 2.0 0.0 BRS-M205-03 53.6 74.8 29.3 10.5 2.8 0.9 0.0 0.0 BRS-M205-04 67.6 20.4 17.3 13.4 1.5 1.6 0.2 0.0 OHA0306-05 58.5 - 23.7 - 1.8 - 1.1 - HAP-W305-06 52.1 62.8 42.3 14.5 1.1 1.3 1.5 0.0 RHA-T305-07 57.3 56.0 28.4 22.5 1.9 2.5 0.8 0.0 OHA-C309-08 59.3 87.4 12.7 5.4 1.9 1.1 1.1 0.0 OHA-T305-09 56.4 52.8 28.3 14.9 2.2 0.9 0.1 0.0 OHA-B305-10 55.0 48.5 23.1 4.2 1.8 1.1 1.2 0.0 RHA0307-11 47.8 28.7 32.2 0.0 2.0 0.3 0.7 0.0 CAP0408-12 4.9 16.1 5.4 0.9 1.3 0.5 0.0 0.0 PBA-CPT-10 55.9 63.1 24.4 13.8 3.1 0.7 0.6 1.0 PDC-CPT-11 70.6 69.2 12.2 4.4 1.3 1.1 0.0 0.0 UG-CE01-0401 51.2 67.4 32.3 18.5 1.9 1.9 0.0 0.0 UG-WE02-1802 48.2 59.8 27.3 18.0 1.7 1.6 1.0 0.0 UG-WE03-0503 56.5 47.8 28.9 15.2 1.3 1.1 0.3 0.0 UG-NO04-2004 22.8 61.0 13.1 1.6 1.2 0.7 0.0 0.0 UG-CE01-0805 48.6 69.0 35.9 16.6 1.9 1.3 1.5 0.0 UG-NO07-0606 34.0 27.3 4.5 14.2 1.4 0.7 0.0 0.0 UG-WE05-0607 47.8 67.3 30.1 15.4 2.1 1.3 1.3 0.0 UG-WE02-1608 6.6 32.5 11.4 0.3 1.8 0.7 0.0 0.0 UG-WE02-1909 44.5 89.3 40.7 25.8 2.1 1.4 1.6 0.0 UG-WE02-0711 20.7 15.5 8.2 2.8 3.0 0.5 0.0 0.0 UG-WE02-0513 62.7 - 27.8 - 1.8 - 1.6 - UG-WE02-1014 0.7 23.6 0.0 2.5 0.0 0.3 0.0 0.0 UG-EA06-0515 9.0 28.1 9.8 0.2 0.9 1.3 0.0 0.0 UG2-WE0106-01 52.5 40.3 23.3 2.4 2.0 0.3 0.0 0.0 UG2-WE0102-02 62.9 48.4 14.9 5.8 1.2 1.1 0.0 0.0 UG2-WE0119-03 48.9 79.8 39.6 13.0 1.8 1.4 0.0 0.0 UG2-WE0103-05 53.4 39.2 15.8 1.7 1.8 0.4 0.0 0.0 UG2-NO0210-06 54.0 20.9 6.0 7.3 1.4 0.8 0.0 0.0 UG2-NO0214-07 43.8 39.1 10.4 1.2 1.4 0.7 0.0 0.0 UG2-NO0215-08 41.1 77.6 14.4 0.9 1.4 0.8 0.0 0.0 UG2-NO0211-09 66.6 40.6 19.8 3.1 1.6 1.4 0.1 0.0 UG2-NO0211-10 13.8 54.7 11.0 0.0 1.2 0.0 0.0 0.0 UG2-NO0217-11 40.9 41.2 5.0 0.0 1.3 0.0 0.0 0.0 UG2-NO0212-12 55.1 52.1 15.3 2.5 1.5 0.7 0.0 0.0 UG2-NO0203-13 49.6 17.4 14.6 3.7 1.4 0.5 0.0 0.0 UG2-WE0307-14 57.5 24.2 1.3 0.0 1.1 0.0 0.0 0.0 UG2-WE0318-15 59.6 55.4 28.0 23.5 2.0 2.3 1.0 0.0 UG2-WE0402-16 41.0 51.3 2.4 0.2 1.2 0.7 0.0 0.0 UG2-WE0419-17 49.9 43.1 42.5 7.6 2.0 0.4 1.4 0.0 UG2-WE0405-18 44.6 58.2 6.3 4.8 1.2 0.3 0.0 0.0 UG2-WE0502-20 49.3 - 6.9 - 1.3 - 0.0 - UG2-WE0507-21 60.6 36.7 17.5 0.0 2.0 0.0 0.2 0.0 UG2-WE0511-22 43.1 20.1 2.6 0.0 0.8 0.0 0.0 0.0 UG2-WE0505-23 61.7 23.9 17.2 5.7 1.6 1.1 0.0 0.0 UG2-EA0604-24 58.8 23.3 20.5 0.0 1.8 0.0 0.0 0.0 UG2-CE0706-25 57.8 55.7 38.1 10.9 2.6 1.5 1.8 0.0 UG2-WE0808-26 64.3 91.8 23.8 11.0 1.5 0.8 0.0 0.0 Mean 48.00 48.30 20.00 7.60 1.70 0.92 0.46 0.02 LSD (5%) 18.30 29.88 14.9 12.02 0.80 1.04 1.16 0.40 P-value <.001 <.001 <.001 <.001 <.001 <.001 <.001 0.505 -The genotypes were not planted in the second season because of poor germination 27

Table 3. Fruit pest infestation by fruit pests in on-farm hot pepper trial Fruit fly Mean number False codling Damaged fruits Genotype infestation (%) of larva per moth (%) fruit infestation (%) NSR0105-02 54.2 22.6 1.9 0.69 BRS-M205-04 69.5 7.0 1.6 0.00 HAP-W305-06 52.7 8.9 1.5 0.00 RHA-T305-07 71.2 19.1 1.9 0.00 OHA-B305-10 44.3 26.3 2.1 0.00 RHA0307-11 71.5 26.6 2.2 0.00 CAP0408-12 1.2 0.0 0.0 0.00 UG-CE01-0401 46.2 17.0 2.4 0.00 UG-WE02-1802 69.8 12.9 1.9 0.40 UG-CE01-0805 58.1 17.2 1.6 0.65 UG-WE05-0607 50.4 18.6 2.1 0.15 UG-WE02-1608 6.3 0.0 0.0 0.00 UG-WE02-1909 56.0 19.1 2.6 0.00 UG-WE02-0513 71.4 4.1 1.4 0.00 UG-WE02-1014 37.8 2.1 1.9 0.00 Mean 50.70 13.40 2.00 0.13 LSD (5%) 28.23 11.93 1.10 0.74 P-value <.001 <.001 <.001 0.559

4.2 RANKING OF THE REACTION OF HOT PEPPER GENOTYPES TO FRUIT FLY ATTACK Fruit damage (those with oviposition and rotting signs) was used to assess reaction of hot pepper genotypes to fruit fly attack as modified from Nath et al. (2017). Genotypes with fruit damage ranging from 1-10% were considered highly resistant, 11-20%, resistant, 21-50%, moderately resistant, 51-75%, susceptible and 76-100%, highly susceptible.

There was variation in the reaction of hot pepper genotypes common to both seasons to fruit fly attack. Only one genotype (CAP0408-12) was highly resistant, four were resistant, 18 were moderately resistant, 24 susceptible while one genotype, UG2-WE0808-26, was very susceptible (Table 4).

On the other hand, genotypes evaluated on the farmer-field, did also show variation in resistance to fruit fly attack. Genotypes CAP0408-12 and UG-WE02-1608 were highly resistant while four were moderately resistant and the rest susceptible (Table 5).

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Table 4. Pooled fruit damage, number of fruit fly larva per fruit and reaction of hot pepper genotypes common to seasons 2017A and 2018B to fruit fly attack evaluated at MUARIK Mean number Hot pepper Reaction to fruit Genotype Damaged fruits (%) of fruit fly type fly attack larva per fruit CAP0408-12 10.5 0.9 Cayenne Highly resistant UG-WE02-1014 12.1 0.2 Cayenne Resistant UG-WE02-0711 18.1 1.7 Cayenne Resistant UG-EA06-0515 18.5 1.1 Bird eye chili Resistant UG-WE02-1608 19.5 1.2 Cayenne Resistant UG-NO07-0606 30.6 1.1 Bird eye chili Moderately resistant UG2-WE0511-22 31.6 0.4 Bird eye chili Moderately resistant UG2-NO0203-13 33.5 1.0 Bird eye chili Moderately resistant UG2-NO0211-10 34.3 0.6 Bird eye chili Moderately resistant UG2-NO0210-06 37.4 1.1 Bird eye chili Moderately resistant RHA0307-11 39.4 1.2 Habanero Moderately resistant UG2-WE0307-14 40.8 0.5 Bird eye chili Moderately resistant UG2-EA0604-24 41.0 0.9 Bird eye chili Moderately resistant UG2-NO0217-11 41.0 0.7 Bird eye chili Moderately resistant UG2-NO0214-07 41.4 1.0 Bird eye chili Moderately resistant UG-NO04-2004 41.9 0.9 Bird eye chili Moderately resistant UG2-WE0505-23 42.8 1.3 Bullet chili Moderately resistant BRS-M205-04 43.9 1.5 Biquinho Moderately resistant UG2-WE0402-16 46.1 0.9 Bird eye chili Moderately resistant UG2-WE0103-05 46.3 1.1 Bullet chili Moderately resistant UG2-WE0106-01 46.4 1.1 Cayenne Moderately resistant UG2-WE0419-17 46.5 1.2 Scotch bonnet Moderately resistant UG2-WE0507-21 48.6 1.0 Serrano Moderately resistant UG2-WE0405-18 51.4 0.8 Bird eye chili Susceptible OHA-B305-10 51.7 1.4 Habanero Susceptible UG-WE03-0503 52.1 1.2 Scotch bonnet Susceptible UG2-NO0211-09 53.6 1.5 Bullet chili Susceptible UG2-NO0212-12 53.6 1.1 Bird eye chili Susceptible UG-WE02-1802 54.0 1.7 Habanero Susceptible OHA-T305-09 54.6 1.5 Habanero Susceptible NSR0105-01 55.2 2.2 Habanero Susceptible UG2-WE0102-02 55.6 1.2 Bullet chili Susceptible RHA-T305-07 56.7 2.2 Habanero Susceptible UG2-CE0706-25 56.8 2.1 Scotch bonnet Susceptible UG2-WE0318-15 57.4 2.1 Habanero Susceptible HAP-W305-06 57.5 1.2 Habanero Susceptible UG-WE05-0607 57.5 1.7 Scotch bonnet Susceptible PBA-CPT-10 58.3 1.9 De cheiro Susceptible UG-CE01-0805 58.7 1.6 Scotch bonnet Susceptible UG-CE01-0401 59.3 1.9 Habanero Susceptible UG2-NO0215-08 59.3 1.1 Bird eye chili Susceptible NSR0105-02 62.6 2.2 Habanero Susceptible BRS-M205-03 64.2 1.8 Calabrian Susceptible UG2-WE0119-03 64.3 1.6 Habanero Susceptible UG-WE02-1909 66.9 1.8 Habanero Susceptible PDC-CPT-11 69.9 1.2 Biquinho Susceptible OHA-C309-08 73.3 1.5 Habanero Susceptible UG2-WE0808-26 78.1 1.2 Unidentified Very susceptible 29

Table 5. Fruit damage, number of fruit fly larva per fruit and reaction of hot pepper genotypes to fruit fly attack evaluated on farmer-field in Ibanda district in season 2018C Mean number of Damaged fruits Hot pepper Reaction to fruit fly Genotype fruit fly larva (%) type attack per fruit CAP0408-12 1.2 0.0 Cayenne Highly resistant UG-WE02-1608 6.3 0.0 Cayenne Highly resistant OHA-B305-10 44.3 2.1 Habanero Moderately resistant UG-CE01-0401 46.2 2.4 Habanero Moderately resistant UG-WE05-0607 50.4 2.1 Scotch bonnet Moderately resistant UG-WE02-1014 37.8 1.9 Cayenne Moderately resistant NSR0105-02 54.2 1.9 Habanero Susceptible BRS-M205-04 69.5 1.6 Biquinho Susceptible HAP-W305-06 52.7 1.5 Habanero Susceptible RHA-T305-07 71.2 1.9 Habanero Susceptible RHA0307-11 71.5 2.2 Habanero Susceptible UG-WE02-1802 69.8 1.9 Habanero Susceptible UG-CE01-0805 58.1 1.6 Scotch bonnet Susceptible UG-WE02-1909 56.0 2.6 Habanero Susceptible UG-WE02-0513 71.4 1.4 Habanero Susceptible

4.3 FRUIT QUALITY TRAITS OF DIFFERENT HOT PEPPER GENOTYPES The average fruit weight differed highly and significantly (P<.001) among genotypes evaluated at MUARIK and as well as between seasons (P<.001). Genotypes in season 2017A generally had heavier fruits (3.5g) than in 2018B (2.8g) (Table 6). Genotypes NSR0105-01 (10.8g) and UG-WE05-0607 (10.3g) had the heaviest fruits in season 2017A while UG2-NO0215-08 (0.3g) and UG-EA06-0515 (0.2g) had the lightest fruits. For 2018B, genotypes UG2-WE0318-15 (9.8g) and UG2-WE0419-17 (9.2g) had the heaviest fruits while UG2-WE0402-16 (0.1g) and UG2-NO0217-11 (0.1g) had the lightest fruits. The average fruit weight also differed significantly (P<.001) among hot pepper genotypes assessed on the farmer-field. Average fruit weight ranged from 1.3 to 10.6g with genotypes UG-CE01-0401(10.6g) having the heaviest fruits. Genotype BRS-M205-04 had the lightest fruits (1.3g) as shown in Table 7.

Fruit length differed highly and significantly among the hot pepper genotypes evaluated at MUARIK and between seasons (P<.001). Genotypes had longer fruits (3.2cm) in season 2017A than in season 2018 B (3.0cm). Genotypes UG-WE02-1608 (7.5cm) and BRS-M205- 03 (6.6cm) had the longest fruits in season 2017A while UG2-WE0307-14 (1.6cm) and UG- EA06-0515 (0.9cm) had the shortest fruits (Table 6). In season 2018B, BRS-M205-03, CAP0408-12 (5.3cm) and UG-WE02-1608 (5.1cm) had the longest fruits while UG2-WE0307- 14 (1.4cm) and UG-EA06-0515 (1.3cm) had the shortest fruits. The fruit length still varied significantly (at P<.001) among hot pepper genotypes evaluated on the farmer-field. Fruit

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length ranged from 2.1 to 6.4cm and genotypes CAP0408-12 and UG-WE02-1014 had the longest fruits, 6.4 and 6.3cm, respectively. On the other hand, BRS-M205-04 (2.1cm) had the shortest fruits (Table 7).

The fruit width like fruit length differed significantly among the genotypes at P<.001 and between seasons (P<.001) (Table 6). Fruits were generally broader in season 2017A (1.7cm) than in 2018B (1.4cm). Genotypes NSR0105-02, UG2-WE0318-15, UG2-WE0419-17, NSR0105-01 and RHA-T305-07 had the broadest fruits with the mean width of 3.2cm in season 2017A (Table 6). UG-WE02-1014, UG2-NO0217-11 and UG-EA06-0515 had the narrowest fruits with average width of 0.5cm (Table 6). In 2018B, RHA-T305-07 (3.1cm), UG2- WE0419-17 and UG2-WE0318-15 (3.0cm) had the widest fruits. Genotypes UG2-NO0217-11 (0.4cm) and UG-EA06-0515 (0.3cm) had the narrowest fruits. The mean width of hot pepper genotypes evaluated on the farmer-field likewise differed significantly (at P<.001). The mean fruit width ranged from 0.7 to 3.4cm among the genotypes. Genotypes UG-WE05-0607, NSR0105-02 registered the widest fruits, 3.4 and 3.2cm wide, respectively. Conversely, CAP0408-12 had the narrowest fruits (0.7cm) as shown in Table 7.

Fruit wall thickness measurements were only taken in season 2018B and it differed highly significantly among the genotypes (P<.001). Genotypes UG2-WE0507-21 (2.0mm) and UG2- CE0706-25 (1.8mm) had the thickest fruit wall whereas UG-NO04-2004 and UG-EA06-0515 (0.2mm) had the thinnest fruits (Table 6). Similarly, fruit wall thickness did vary significantly among hot pepper genotypes assessed on the farmer-field (at P<.001). Fruit wall thickness ranged from 0.4 to 1.8mm among the genotypes. Genotype, RHA0307-11, had the thickest fruit walls (1.8mm) while CAP0408-12 (0.4mm) registered the thinnest fruit walls (Table 7).

The penetration force of the fruit flesh differed significantly among genotypes (P<.001) (Table 6). There was no significant difference in the required penetration force between seasons. Genotypes RHA0307-11 (2.2N) and PDC-CPT-11(1.9N) fruits required the highest penetration force in season 2017A while UG-EA06-0515, UG-NO04-2004 and UG2-NO0212- 12 fruits required the least penetration force of 0.5N. In season 2018B, genotypes BRS-M205- 03 (2.1N) and UG2-WE0507-21(2.0N) had the toughest fruits while UG2-WE0808-26, UG2- NO0215-08 and UG2-NO0217-11 had the softest fruits at 0.5N. The penetration force among the hot pepper genotypes evaluated at the farmer-field also differed significantly (at P<.001). Penetration force ranged from 0.9 to 2.1N among the genotypes with an average of 1.48N.

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Genotypes OHA-B305-10 and RHA0307-11 registered the toughest fruits, at 2.1, and 2.0N, respectively while CAP0408-12 had the softest fruits (0.9N) (Table 7).

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Table 6. Means of fruit quality traits for hot pepper genotypes evaluated in MUARIK, Uganda in seasons 2017A and 2018B Genotype Weight (g) Length (cm) Width (cm) FWT (mm) PF (N) MF (%) 2017A 2018B 2017A 2018B 2017A 2018B 2017A 2018B 2017A 2018B 2017A 2018B NSR0105-01 10.8 7.7 3.8 3.4 3.2 2.9 1.3 1.2 1.2 0.0 30.5 NSR0105-02 10.1 7.0 4.0 3.8 3.2 2.6 0.9 1.1 1.4 1.9 21.7 BRS-M205-03 7.5 4.3 6.6 5.3 1.4 1.2 1.0 1.9 2.1 4.0 16.6 BRS-M205-04 1.2 1.2 2.0 2.0 1.5 1.3 0.9 1.2 1.2 6.7 71.7 OHA0306-05 5.5 - 3.0 - 2.5 - - 0.7 - 1.1 - HAP-W305-06 7.4 3.8 3.4 3.2 2.5 2.0 1.2 1.3 1.4 28.3 27.0 RHA-T305-07 9.8 8.2 3.7 3.7 3.2 3.1 1.3 1.1 1.2 6.1 35.8 OHA-C309-08 6.1 2.5 3.1 2.6 2.5 2.0 1.1 1.6 1.3 1.6 9.1 OHA-B305-10 3.2 3.6 3.0 2.8 2.5 1.8 1.0 1.7 1.3 0.0 15.1 OHA-T305-09 6.7 4.6 3.0 3.5 2.7 2.2 1.2 1.1 1.3 10.8 35.9 RHA0307-11 3.1 3.6 2.7 3.0 2.3 2.3 1.4 2.2 1.8 5.6 41.5 CAP0408-12 1.3 1.5 5.2 5.3 0.8 0.7 0.3 1.3 1.4 42.2 30.6 PBA-CPT-10 3.9 4.6 4.7 3.9 2.6 2.0 1.4 1.8 1.6 0.0 23.4 PDC-CPT-11 1.2 1.0 1.7 1.9 1.5 1.1 1.2 1.9 1.9 0.9 21.8 UG-CE01-0401 6.3 5.1 4.2 3.4 2.8 2.4 1.3 1.2 1.5 0.6 20.9 UG-WE02-1802 9.7 8.4 4.7 4.5 2.6 2.6 1.5 1.5 1.2 4.1 28.3 UG-WE03-0503 4.5 2.8 3.3 3.3 2.0 1.6 0.9 1.3 1.4 1.5 44.2 UG-NO04-2004 0.3 0.3 2.6 1.8 0.8 0.5 0.2 0.5 0.7 23.5 31.2 UG-CE01-0805 9.8 6.4 4.3 3.6 2.9 2.6 1.0 1.2 1.3 3.9 22.6 UG-NO07-0606 0.7 0.4 2.2 1.9 0.8 0.6 0.4 1.2 1.0 44.4 64.4 UG-WE05-0607 10.3 6.5 3.6 2.9 3.1 2.8 1.3 1.1 1.3 2.1 26.2 UG-WE02-1608 2.0 1.5 7.5 5.1 1.0 0.8 0.6 1.1 1.3 76.1 42.6 UG-WE02-1909 9.3 5.8 4.3 3.8 2.8 2.8 1.4 1.7 1.8 4.0 9.6 UG-WE02-0711 1.6 1.3 3.1 3.5 1.0 0.8 0.4 0.8 1.3 64.9 64.0 UG-WE02-0513 4.1 - 2.9 - 2.4 - - 1.7 - 0.8 - UG-WE02-1014 1.5 1.1 3.6 4.4 0.5 0.6 0.3 1.4 1.0 37.7 20.6 UG-EA06-0515 0.2 0.2 0.9 1.3 0.5 0.3 0.2 0.5 0.8 53.0 21.6 UG2-WE0106-01 2.2 1.4 5.1 4.2 0.9 0.7 0.4 1.6 1.5 10.7 49.3 UG2-WE0102-02 1.3 0.7 2.6 2.2 0.9 0.8 0.4 1.0 0.9 15.5 39.7 UG2-WE0119-03 3.6 1.9 2.9 2.8 1.9 1.4 1.2 1.3 1.3 0.0 15.2 UG2-WE0103-05 1.4 1.8 2.5 3.0 1.0 1.0 1.0 1.0 1.0 31.1 52.0 UG2-NO0210-06 0.5 0.3 2.5 1.6 0.9 0.5 0.6 1.0 0.6 10.5 47.5 UG2-NO0214-07 0.5 0.4 2.3 2.0 0.8 0.5 0.8 0.8 0.8 13.2 34.1 UG2-NO0215-08 0.3 0.3 1.8 1.6 0.9 0.5 0.5 1.0 0.5 12.4 14.7 UG2-NO0211-09 1.7 1.4 3.0 2.8 1.0 1.0 0.7 0.7 0.7 15.9 57.6 UG2-NO0211-10 1.6 0.8 4.1 3.7 1.0 0.9 1.0 0.7 1.0 51.5 37.6 UG2-NO0217-11 0.4 0.1 2.4 1.7 0.5 0.4 0.5 0.9 0.5 31.5 32.8 UG2-NO0212-12 0.4 0.4 2.4 2.0 0.8 0.5 0.6 0.5 0.6 14.6 23.9 UG2-NO0203-13 0.4 0.4 2.3 1.9 0.9 0.6 1.0 1.1 1.0 7.3 42.8 UG2-WE0307-14 0.4 0.3 1.6 1.4 0.6 0.5 1.2 1.1 1.2 15.4 42.0 UG2-WE0318-15 5.6 9.8 4.0 4.3 3.2 3.0 1.4 1.3 1.4 0.2 30.9 UG2-WE0402-16 0.3 0.1 1.9 1.8 0.7 0.5 0.8 0.8 0.8 31.7 31.4 UG2-WE0419-17 6.8 9.2 3.6 4.0 3.2 3.0 1.1 1.5 1.1 0.0 40.1 UG2-WE0405-18 0.4 0.3 2.0 1.6 0.8 0.6 0.4 0.9 0.8 16.5 30.3 UG2-WE0502-20 0.7 - 2.0 - 0.7 - - 1.1 - 25.2 - UG2-WE0507-21 2.0 1.1 3.8 2.5 1.3 0.9 2.0 1.7 2.0 5.3 19.6 UG2-WE0511-22 1.0 0.7 2.2 2.1 0.8 0.8 1.6 1.8 1.6 21.3 48.3 UG2-WE0505-23 1.3 1.1 2.2 2.2 1.0 0.9 1.5 1.2 1.5 13.7 48.2 UG2-EA0604-24 2.6 1.0 4.8 3.7 1.0 0.7 1.3 1.3 1.3 12.8 30.3 UG2-CE0706-25 5.9 5.8 2.9 2.5 2.9 2.5 1.8 1.5 1.8 0.0 33.7 UG2-WE0808-26 1.4 1.2 2.8 2.4 1.5 1.0 0.5 0.7 0.5 0.2 5.2 Mean 3.50 2.80 3.20 3.00 1.70 1.40 0.96 1.21 1.18 15.4 33.09 LSD (5%) 1.84 1.51 0.29 0.33 0.13 0.14 0.20 0.256 0.246 11.7 26.81 P-value <.001 <.001 <.001 <.001 <.001 <.001 <.001 <.001 <.001 <.001 <.001 FWT=fruit wall thickness, PF= penetration force, MF= marketable fruits, NMF= non-marketable fruits 33

Table 7. Fruit quality traits of hot pepper genotypes evaluated on farmer-field Fruit Fruit Fruit Fruit wall Penetration Marketable Genotype weight length width thickness force (N) fruits (%) (g) (cm) (cm) (mm) NSR0105-02 7.3 4.0 3.2 1.0 1.3 0.0 BRS-M205-04 1.3 2.1 1.5 1.1 1.8 2.1 HAP-W305-06 3.5 3.2 2.4 1.6 1.7 0.8 RHA-T305-07 6.8 3.9 3.1 1.4 1.6 0.0 OHA-B305-10 3.5 3.0 2.4 1.4 2.1 0.0 RHA0307-11 4.4 3.3 2.5 1.8 2.0 0.0 CAP0408-12 1.4 6.4 0.7 0.4 0.9 58.6 UG-CE01-0401 10.6 4.9 3.0 1.4 1.4 1.8 UG-WE02-1802 7.1 5.0 2.6 1.4 1.3 0.5 UG-CE01-0805 9.5 4.5 3.0 1.4 1.5 0.8 UG-WE05-0607 9.8 3.8 3.4 1.5 1.2 0.0 UG-WE02-1608 1.8 6.0 0.9 0.5 1.2 49.0 UG-WE02-1909 9.8 4.7 2.8 1.1 1.6 0.3 UG-WE02-0513 3.1 3.2 2.4 1.0 1.6 0.0 UG-WE02-1014 2.0 6.3 0.9 0.5 1.1 23.4 Mean 5.47 4.3 2.3 1.16 1.48 9.1 LSD (5%) 1.65 0.80 0.31 0.26 0.30 15.02 P-value <.001 <.001 <.001 <.001 <.001 <.001

4.4 EFFECT OF HOT PEPPER GENOTYPES ON YIELD PERFORMANCE

4.4.1 Total fruit yield (tha-1)

Total fruit yield differed highly significantly among genotypes and between seasons (P<.001). Fruit yield ranged from 0.7 tha-1 and 3.3 tha-1 in season 2017Aand from 0.05 and 4.0 t/ha in 2018B. Genotypes had far much higher average yield (3.3 tha-1) in season 2017Athan in 2018B (0.7 t/ha) (Table 8). UG-WE02-1802 (15.3 tha-1) and UG-WE02-1909 (13.9 tha-1) had the highest yields in season 2017Awhile UG2-WE0106-01 (0.5 tha-1) and UG2-WE0102-02 (0.4 tha-1) gave the lowest yields. In 2018B, genotypes BRS-M205-04 (4.0 tha-1) and UG-WE02- 1802 (2.2 tha-1) gave the highest yield. Conversely, genotype UG2-NO0217-11 (0.05 tha-1) had the lowest yield.

Total fruit yield also varied significantly among hot pepper genotypes evaluated on the farmer- field (at P<.001). Total fruit yield varied from 41.5 to 4.9 tha-1 and an average of 20.7 tha-1 was recorded. BRS-M205-04 and UG-WE02-1909 had the highest yield, 41.5 and 40.8 tha-1, respectively. Conversely, genotypes, UG-WE02-0513 and CAP0408-12 had the lowest yield, 4.9 and 5.6 tha-1, respectively (Table 9).

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4.4.2 Number of fruits per plant

The number of fruits per plant varied significantly among genotypes and seasons (P<.001). Genotypes had more fruits per plant in season 2017A (78.2) than in 2018B (20.7). UG-EA06- 0515 and BRS-M205-04 had more fruits per plant, 326.4 and 283 fruits, respectively in season 2017Athan other genotypes. On the other hand, PBA-CPT-10 and UG2-WE0119-03 had the least average number of fruits per plant (7.3 and 8.3, respectively). In 2018B, BRS-M205-04 (135.7), UG-WE02-1608 (63.1) had the highest mean number of fruits per plant while RHA0307-11 while PBA-CPT-10 had the least numbers, 1.2 and 2.0, respectively (Table 8).

The number of fruits per plant similarly differed significantly among hot pepper genotypes assessed on the farmer-field (at P<.001) (Table 9). The average number of fruits recorded in the trial was 36.9 and range, 12.3-142.6. Genotype BRS-M205-04, registered the highest number of fruits per plant (142.6) while UG-WE02-0513 had the lowest number of fruits per plant (12.3).

4.4.3 Marketable fruits (%)

Generally, the mean percentages of marketable fruits were low though they differed significantly among genotypes (at P<.001) as well as between seasons. Genotypes had the highest percentage of marketable fruits in 2018B (33.1%) but fewer marketable fruits in season 2017A(15.4%). UG-WE02-1608 and UG-WE02-0711 had more marketable fruits in season 2017Aat 76.1% and 64.9% respectively than the other genotypes. Meanwhile NSR0105-01, OHA-T305-09, PBA-CPT-10, UG2-CE0706-25, UG2-WE0119-03 and UG2-WE0419-17 did not have marketable fruits at all. In 2018B, BRS-M205-04 and UG-NO07-0606 had the highest percentage of marketable fruits, 71.7% and 64.4%, respectively, while OHA-C309-08 (9.1%) and UG2-WE0808-26 (5.2%) had the least (Table 8).

From the farmer-field hot pepper evaluation trial, the percentage marketable fruits differed significantly (at P<.001) among genotypes. Genotypes, NSR0105-02, OHA-B305-10, RHA- T305-07, RHA0307-11, UG-WE02-0513, and UG-WE05-0607 had no marketable fruits while CAP0408-12 and UG-WE02-1608 registered the highest percentage of marketable fruits, 58.6 and 49.0%, respectively (Table 9).

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Table 8. Yield performance of hot pepper genotypes evaluated in MUARIK, Uganda in seasons 2017A and 2018B Yield (tha-1) Marketable fruit yield (tha-1) Mean number of fruits per plant Genotype 2017A 2018B 2017A 2018B 2017A 2018B NSR0105-01 1.77 0.79 0.00 0.36 11.3 5.6 NSR0105-02 2.14 0.74 0.05 0.16 16.6 4.5 BRS-M205-03 5.89 0.57 0.98 0.11 67.4 8.1 BRS-M205-04 8.40 3.96 1.06 3.87 283.3 135.7 OHA0306-05 1.31 ˗ 0.03 ˗ 15.7 ˗ HAP-W305-06 1.68 0.47 0.76 0.16 14.4 6.9 RHA-T305-07 8.74 1.43 0.74 0.83 54.7 7.7 OHA-C309-08 1.69 0.16 0.16 0.02 18.4 3.1 OHA-T305-09 2.58 0.44 0.00 0.07 30.1 8.8 OHA-B305-10 2.01 0.51 0.42 0.22 20.7 5.5 RHA0307-11 0.72 0.13 0.05 0.05 11.5 1.2 CAP0408-12 1.22 0.88 0.71 0.42 51.6 49.4 PBA-CPT-10 0.59 0.15 0.00 0.06 7.3 2.0 PDC-CPT-11 1.86 0.67 0.03 0.21 88.8 47.1 UG-CE01-0401 10.90 0.75 0.15 0.29 70.9 7.6 UG-WE02-1802 15.29 2.16 1.02 0.93 94.2 15.4 UG-WE03-0503 3.33 0.49 0.15 0.15 46.2 8.8 UG-NO04-2004 1.54 0.15 0.34 0.05 145.3 16.0 UG-CE01-0805 10.45 1.67 0.79 0.72 70.4 13.5 UG-NO07-0606 1.81 0.28 0.91 0.19 131.4 17.9 UG-WE05-0607 10.61 1.40 0.40 0.44 63.5 12.3 UG-WE02-1608 6.76 1.51 5.73 0.85 183.1 63.1 UG-WE02-1909 13.88 0.39 0.93 0.06 76.1 3.1 UG-WE02-0711 5.11 0.73 3.77 0.53 180.1 31.6 UG-WE02-0513 2.59 ˗ 0.01 ˗ 28.6 ˗ UG-WE02-1014 0.32 0.07 0.11 0.02 9.1 4.2 UG-EA06-0515 1.37 0.14 0.88 0.07 328.4 33.4 UG2-WE0106-01 0.45 0.34 0.11 0.22 11.3 7.4 UG2-WE0102-02 0.44 0.22 0.14 0.09 17.1 25.4 UG2-WE0119-03 0.67 1.03 0.00 0.19 8.3 28.1 UG2-WE0103-05 3.34 0.66 1.44 0.42 120.6 24.9 UG2-NO0210-06 1.78 0.41 0.28 0.20 122.6 35.5 UG2-NO0214-07 2.35 0.20 0.39 0.08 199.1 25.5 UG2-NO0215-08 1.60 0.13 0.41 0.04 124.0 16.4 UG2-NO0211-09 3.71 1.06 0.89 0.75 108.3 39.1 UG2-NO0211-10 1.05 0.19 0.70 0.14 37.0 7.3 UG2-NO0217-11 2.14 0.05 0.75 0.02 194.2 8.9 UG2-NO0212-12 1.46 0.17 0.49 0.04 84.7 19.2 UG2-NO0203-13 0.56 0.13 0.04 0.05 48.2 13.3 UG2-WE0307-14 0.79 0.26 0.14 0.14 118.2 47.8 UG2-WE0318-15 7.75 1.31 0.02 0.58 53.5 8.9 UG2-WE0402-16 1.44 0.29 0.40 0.13 188.0 36.1 UG2-WE0419-17 5.22 0.72 0.00 0.42 35.9 4.1 UG2-WE0405-18 0.76 ˗ 0.15 ˗ 86.3 ˗ UG2-WE0502-20 1.27 0.34 0.63 0.05 107.5 9.9 UG2-WE0507-21 1.40 0.23 0.12 0.09 41.2 15.4 UG2-WE0511-22 0.52 0.89 0.19 0.52 29.7 13.1 UG2-WE0505-23 0.87 0.73 0.20 0.40 39.9 48.4 UG2-EA0604-24 1.28 0.69 0.64 0.29 40.8 27.9 UG2-CE0706-25 1.84 0.13 0.00 0.01 13.1 5.7 UG2-WE0808-26 0.68 0.34 0.00 0.33 18.3 5.8 Mean 3.31 0.65 0.56 0.50 78.19 20.68 LSD (5%) 2.44 0.91 0.59 0.05 61.90 27.34 P-value <.001 <.001 <.001 <.001 <.001 <.001 -The genotypes were not planted in the second 2018Because of poor germination 36

Table 9. Yield parameters of genotypes evaluated on farmer-field in Ibanda district Genotype Yield (tha-1) Marketable fruit yield (tha-1) Number of fruits per plant NSR0105-02 21.9 0.0 20.0 BRS-M205-04 41.5 1.8 142.6 HAP-W305-06 11.5 0.2 21.1 RHA-T305-07 20.4 0.0 17.8 OHA-B305-10 10.4 0.0 20.1 RHA0307-11 12.6 0.0 18.7 CAP0408-12 5.6 4.2 23.9 UG-CE01-0401 17.0 0.8 30.0 UG-WE02-1802 37.2 0.2 38.9 UG-CE01-0805 25.3 0.5 27.0 UG-WE05-0607 31.2 0.0 31.8 UG-WE02-1608 20.4 11.2 67.3 UG-WE02-1909 40.8 0.2 45.8 UG-WE02-0513 4.9 0.0 12.3 UG-WE02-1014 10.3 4.4 36.3 Mean 20.7 1.6 36.9 LSD (5%) 15.4 5.38 31.5 P-value <.001 0.012 <.001

4.5 Coefficients of correlation for the relationships between fruit pest infestation and fruit traits of hot pepper genotypes evaluated in MUARIK

The correlations coefficients for individual seasons at MUARIK are presented in Appendices. Generally, results showed that most of the fruit traits had significant relationships with pest infestation in both seasons at MUARIK. Fruit damage showed significant positive correlation with fruit fly infestation, number of larvae per fruit, fruit width, fruit weight and penetration force (r=0.28, 0.27, 0.24 and 0.34, and 0.26, respectively) (Table 10). Fruit fly infestation correlated positively and significantly with number of fruit fly larvae per fruit, average fruit weight, fruit length, fruit width, and penetration force (r=0.56, r=0.59, r=0.30, r=0.63, and r=0.24, respectively). While the false coddling moth infestation similarly correlated to the average fruit weight, fruit length, fruit width (r=0.50, r=0.17, r=0.50, respectively), it had no significant relationship with penetration force (Table 10).

In the on-farm trial, the relationships between fruit fly infestation and fruit traits were more or less similar to that of hot pepper genotypes evaluated at MUARIK except that the relationship with fruit weight was not significant and that with fruit length was negative (r=-0.40). There were no significant relationships between FCM infestation and fruit traits of hot pepper genotypes evaluated on the farmer-field in this study (Table 11).

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Table 10. Correlation coefficients for the relationship between fruit pest infestation and hot pepper fruit traits pooled over the two seasons at MUARIK Damaged% FFL% FCM% No. L/F Few FL FW PF Damage% - FFL% 0.28*** - FCM% 0.09 0.50*** - No. L/F 0.27*** 0.56*** 0.31*** - Few 0.24*** 0.59*** 0.50*** 0.43*** - FL -0.03 0.30*** 0.17** 0.28*** 0.50*** - FW 0.34*** 0.63*** 0.50*** 0.49*** 0.89*** 0.39*** - PF 0.26*** 0.24*** 0.11 0.17** 0.30*** 0.29*** 0.37*** - Damaged% = damaged fruits, FFL%=fruits infested by fruit fly, FCM%=FCM infestation, No. L/F=number of fruit fly larvae per fruit, Few= average fruit weight, FL=fruit length, FW=fruit width, PF=penetration force *significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

Table 11. Correlation coefficients for the relationship between fruit pest infestation and fruit parameters of genotypes evaluated on farmer-field Damaged FFL% FCM% No.L/F Few FL FW FWT PF Damaged - FFL% 0.30* - FCM% 0.11 -0.07 - No. L/F 0.51*** 0.55*** 0.13 - Few 0.28 0.47** 0.25 0.48*** - FL -0.56*** -0.40*** -0.08 -0.34* 0.02 - FW 0.54*** 0.65*** 0.18 0.55*** 0.82*** -0.40** - FWT 0.63*** 0.61*** 0.08 0.51*** 0.48*** -0.60*** 0.76*** - PF 0.50*** 0.45** -0.11 0.39** 0.04 -0.65*** 0.31* 0.57*** - Damaged=damaged fruits, FFL%=fruits infested by fruit fly, FCM%=FCM infestation, No.L/F=number of fruit fly larvae per fruit, Few= average fruit weight, FL=fruit length, FW=fruit width, PF=penetration force *significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

4.6 Correlation coefficients for the relationships between yield and fruit traits of hot pepper genotypes pooled over the two seasons at MUARIK and on farmer-field

The correlations coefficients for individual seasons at MUARIK are presented in Appendices. All fruit traits had significant correlations with yield. Generally, fruit traits; number of fruits per plant, average fruit weight, fruit width and fruit length correlated positively and significantly with yield (r=0.40, r=0.48, r=0.41 and r=0.33, respectively). However, there was

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significant negative correlation between yield and the percentage of marketable fruits (r=-0.22) (Table 12). In the on-farm trial, only fruit traits; number of fruits per plant and fruit weight significantly correlated to yield (r=0.65 and r=0.38, respectively) while fruit length, width, fruit wall thickness and marketable fruits did not significantly correlate with yield (Table 13).

Table 12. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes common in both seasons 2017A and 2018B evaluated in at MUAURIK

Y(t/ha) No. F/P Few FW FL MF% Y(t/ha) - No. F/P 0.40*** - Few 0.48*** -0.24*** - FW 0.41*** -0.25*** 0.89*** - FL 0.33*** -0.15* 0.50*** 0.39*** - MF% -0.22*** 0.14* -0.30*** -0.37*** -0.04 - Y(t/ha)=yield, No.F/P=number of fruits per plant, Few=average fruit weight, FW=fruit width, FL=fruit length, MF%=marketable fruits (%) *significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

Table 13. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes evaluated on the farmer field in Ibanda district Y(t/ha) No. F/P Few FW FL FWT MF% Y(t/ha) - No. F/P 0.65*** - Few 0.38*** -0.22 - FW 0.25 -0.32* 0.82*** - FL -0.09 -0.13 0.02 -0.40*** - FWT 0.17 -0.17 0.48*** 0.76*** -0.60*** - MF% -0.24 0.08 -0.49*** -0.75*** 0.65*** -0.75*** - Y(t/ha)=yield, No.F/P=number of fruits per plant, Few=average fruit weight, FW=fruit width, FL=fruit length, MF%=marketable fruits (%), NMF%=non-marketable fruits (%), FWT=fruit wall thickness *significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

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4.7 DISCUSSION

4.7.1 Effect of hot pepper genotypes and seasons on fruit damage

Results indicated that 48% mean fruit damage due to fruit pests was registered across seasons in MUARIK while 50.7% fruit damage was recorded in the farmer-field trial in Ibanda district. These findings are similar to those of Muzira (2015) who reported losses in hot pepper due to fruit-damaging pests at 55%. However, fruit damage varied significantly among the hot pepper genotypes. One exotic genotypes CAP0408-12 and four local genotypes, UG-WE02-1014, UG-WE02-0711, UG-EA06-0515 and UG-WE02-1608 had the lowest fruit damage. Varying levels of pest damage have been observed in other crops such as tomatoes (Balagawi et al., 2005), bitter gourd (Nath et al., 2017) and in mangoes (Nankinga et al., 2014). The variation in damage can be traced to the innate morphological and biochemical bases of the genotypes. These properties have been shown to even vary among plants within the same species (Pedigo & Rice, 2014). Fruit damage did not differ significantly between seasons because there was minimal variation in the temperatures between the two seasons. Insect pressure (damage) has been reported to increase with environmental factors such as temperature (Taylor et al., 2018). There was a minimal variation in the mean temperatures between seasons in MUARIK and hence this could explain why there was no significant difference in the fruit fly infestations.

4.7.2 Effect of hot pepper genotypes and season on fruit fly infestation

Fruit fly infestation varied significantly among hot pepper genotypes. According to Diatta et al. (2013), fruits of different varieties within the same species are preferred and utilized differently by fruit flies. Other researches have also reported variations in resistance of other crop genotypes to fruit flies (Sarfraz et al., 2006; Gogi et al., 2010; Nankinga et al., 2014). This can be attributed to the physical and chemical fruit traits such as size, colour and total soluble solids that vary among genotypes. These traits have also been reported to influence oviposition preference, and larval growth and development (Dhillon et al., 2005; Aluja & Mangan, 2008; Gogi et al., 2010).

The number of fruit fly larvae per fruit significantly varied among hot pepper genotypes. This difference could have as well been as result of the variation in physical and chemical fruit traits present in the genotypes. Fruit traits such as fruit weight, length, width, fruit wall thickness, colour and flesh penetrability are known to influence the number of larva per fruit (Aluja & Mangan, 2008). Large heavy fruits tend to have more larva per fruit unlike small and light 40

fruits. Heavy fruits may have more substrate volume to support the growth of more larva per fruit unlike the small and light fruits that have less food resources (Aluja & Mangan, 2008).

The number of larva per fruit varied significantly between seasons and this could have been due to variations in the environmental conditions. Environmental conditions such as drought or water stress are known to affect the physiological processes of plants resulting in fewer fruits and quality drawbacks (Haldhar et al., 2013) which was evident in season 2018B (Appendix 7). Although there was no substantial variation in the average temperatures between the two seasons in the on-station evaluation experiment, the mean rainfall quantities varied. This is due to three dry consecutive months (December to February) in season 2018B (Appendix 7). This affected fruit production of the hot pepper genotypes and hence fewer fruits per plant.

Having fewer fruits increases competition for oviposition sites and may induce both intra and interspecific multiple fruit oviposition tendency in tephritid flies and hence increase in fruit damage. However, due to the low nutritional quality of the fruits, the larva survival rate is reduced and hence the number of larva per fruit (Aluja & Mangan, 2008). Effect of hot pepper genotypes on false coddling moth infestation

False coddling moth infestation (FCM) was generally very low during the experimental period though it varied significantly between hot pepper genotypes. Hepburn (2007) also reported low FCM infestation and damage in capsicum. However, there have been no studies to compare different capsicum varieties to FCM infestation like in other crops. For instance, Love et al. (2014) reported differences in susceptibility of different citrus varieties to the pest. It also seems fruit size had a profound effect on FCM infestation since only hot pepper genotypes with large fruits registered infestations and not those with small fruits. This has a profound implication on the market of hot pepper since hot pepper genotypes with big sized fruits fetch more revenue at the international market (Besigye, 2015).

The variation in FCM infestation between seasons could have been due to other hosts such as eggplants present in 2018B and not in 2017A. The false coddling moth is a polyphagous pest (EPPO, 2013) and may have preferred other hosts to hot pepper. Also important to note is the genotypes that had low fruit fly infestation, generally also had low FCM infestation. This may indicate that the phyto-defenses responsible for resistance to fruit flies are also effective against the FCM.

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4.7.4 Ranking of the reaction of hot pepper genotypes to fruit fly attack The hot pepper genotypes showed variation in rankings to fruit fly attack. Conversely, Wingsanoi et al. (2013) evaluated five cultivars of pepper (Capsicum annum) but found no significant variation in their susceptibility to Bactrocera latifrons infestation. However, Bagalawi et al. (2005) reported that Bactrocera tryoni preferred Grosse Lisse and Roma tomato cultivars to cherry tomato. The differences can be associated to fruit morphological traits of the fruits of the different genotypes (Bagalawi et al., 2005). However, phytochemicals from other plant parts such as leaves could also have contributed to the levels of resistance to pest (Pedigo & Rice, 2014). For this study, fruit morphological traits were examined and the correlation analysis revealed positive and significant associations between most of the traits (fruit weight, width, length and fruit wall thickness) and fruit fly infestation and number of fruit fly larvae per fruit. The genotypes that were highly resistant also had inferior fruit traits with a few exceptions while those that ranked susceptible also had superior fruit traits.

4.7.5 Effect of fruit traits on fruit damage Significant positive correlations were obtained between fruit weight, width, penetration force and fruit wall thickness and fruit damage. Balagawi et al. (2005) reported that larger tomatoes were more prone to fruit fly oviposition or damage than smaller ones. However, tomato flesh penetrability or toughness had a negative association with fruit fly damage/oviposition. Fruit toughness has been reported in other related studies to be negatively associated to fruit fly infestation (Gogi et al., 2010; Nath et al., 2017; Rattanapun et al., 2009). Diaz-Fleischer & Aluja (2003) examined the egg clutch size deposited in unripe (firm) and ripe (soft) mangoes by Anastrepha ludens. The fruit fly laid more or bigger egg clutches in unripe (firmer) fruits than in ripe (soft) fruits to increase the survival rate of her offspring. Moreover, the firmer fruits examined in this study were superior in fruit traits such as size (fruit width and weight) that are important in host location and utilization by pests especially the fruit flies (Aluja & Mangan, 2008). Hence, it was worthwhile damaging (ovipositing in) more firm fruits than the soft ones. The findings of this study imply that heavy, broad, tough and thicker fruits are prone to more pest damage than light, narrow, less tough and thin fruits.

4.7.6 Effect of fruit traits on fruit fly infestation

Significant positive correlations were obtained between fruit weight, width, length and fruit wall thickness and fruit fly infestation. This is in agreement with Gogi et al. (2010) who reported significant positive correlations between fruit fly infestation in Momordica charantias 42

L. genotypes and fruit length and diameter (width). Furthermore, they reported that fruit diameter and pericarp toughness were the major factors that influenced fruit fly infestation. In this study, fruit weight, width and fruit wall thickness were the traits that significantly and positively influenced fruit damage and fruit fly infestation.

The positive relationship between fruit penetration force and fruit fly infestation obtained in this particular study is rare. Diaz-Fleischer & Aluja (2003) reported higher Anastrepha ludens larva survival in firm fruits than softer fruits. However, observation of the data revealed that fruits that had high flesh firmness were also wider and heavier. Fruit size is positively associated to substrate volume (Aluja & Mangan, 2008). Therefore, the firm and larger fruits could have provided more food for the growth and development of the fruit fly larva than small and softer fruits and hence the higher infestation. More still, the genotypes with wider and heavy fruits had high pest damage, fruit fly infestation and number of larva per fruit.

Fruit traits of length, width (fruit size) and fruit wall thickness correlated positively and significantly with the number of fruit fly larvae per fruit. Generally, genotypes with bigger fruits and thicker fruit walls had more larvae per fruit which is in agreement with the findings of Dhillon et al. (2005) and Haldhar et al. (2013) who reported that larval density (number of larva per fruit) was positively correlated with fruit length, diameter and flesh thickness. Large host size and thicker fruit wall are likely to offer more volumes nourishment to the developing larva than smaller fruits with thin fruit walls.

4.7.7 Effect of fruit traits on false codling moth (FCM) infestation of hot pepper genotypes

Fruit width and weight significantly and positively correlated with false codling moth (FCM) infestation and were the major fruit traits that influenced FCM infestation of hot pepper genotypes. This implies that big sized and heavy hot pepper fruits, which constitute much of the export volumes, are also more susceptible to FCM infestation than small sized light fruits. FCM larvae are voracious feeders and usually only one larva is found per fruit (Stotter, 2009) and hence the larger the unit area of the host, the more substrate resources are available for pest growth and development. Therefore, much more efforts are necessary in the management of the pest in the most valuable (big fruit-sized) hot pepper genotypes on the international market without comprising the maximum residual levels requirements for pesticides.

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4.7.8 Hot pepper fruit traits and yield performance

Yield varied significantly among hot pepper genotypes and between seasons. The variation in the yield performance of the different genotypes is attributed to their genetic potential (Pawar, 2016). However, environmental factors also influence yields of crops (Amati et al., 2002). Hot pepper genotypes that had heavy and broad fruits also had the highest yield (t/ha) even when they had fewer fruits. This is because fruit weight contributed more to yield than other fruit yield components such as number of fruits per plant. The number of fruits per plant, fruit width and length have also been reported to contribute to yield (Hasanuzzaman & Golam, 2011; Yatagiri et al., 2017) which is in agreement with the findings of this study.

Generally, the percentage of marketable fruits across all genotypes was low. This is attributed to the high fruit pest damage registered among the genotypes. Kakar et al. (2014) reported yield losses due to fruit pests of up to 100% in absence of control measures. Since there was no pesticide use in this study, yield losses due to pests was high which is in agreement with the findings of Amalia et al. (2014). This also proves that host plant resistance alone does not offer complete protection from yield losses resulting from pests. However, genotypes such as CAP0408-12 and UG-WE02-1608 that were highly resistant to fruit damage and pest infestation also had the highest percentage of marketable fruits. Hence, crop resistance offers some protection against marketable yield losses and can be used to reduce inappropriate use of pesticides in integrated pest management strategies.

Furthermore, yield and fruit traits also varied significantly between seasons and weather was probably the major cause of the variation. Rajasekar et al. (2013) reported that weather influenced yield and growth parameters of vegetables. Water stress has been reported to induce flower abortion resulting in fewer fruits per plant and yield (Amati et al., 2002). This explains why there were fewer fruits per plant and less yield in 2018B. Therefore, to ensure proper yield, it is also important to provide the crop with adequate amounts of water.

In general, fruit weight, width and number of fruits per plant correlated positively and significantly with yield. Therefore, since these fruit traits contributed more to yield than other fruit traits, they should be used in hot pepper crop improvement breeding programs.

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CHAPTER FIVE

5.0 GENERAL DISCUSSION, CONCLUSIONS AND RECOMMENDATIONS

5.1 General discussion Genotypes, CAP0408-12 (cayenne), UG-WE02-1014 (cayenne), UG-WE02-0711 (bullet chili), UG-EA06-0515 (bird eye chili) and UG-WE02-1608 (cayenne) have substantial resistance to fruit pest infestation. All the genotypes were sourced from Uganda with exception of the first CAP0408-12. Genotypes OHA-C309-08, UG-WE02-1909 and UG2-WE0119-03 (habanero), UG-CE01-0805, UG-WE05-0607, and UG2-CE0706-25 (scotch bonnet) were more susceptible to fruit pest infestation and yet they contribute the largest portion of Uganda’s export volumes on the international hot pepper market. Therefore, new genotypes belonging to the commercial types; scotch bonnet and habanero should be tested in the future for resistance to the fruit pests. The market for cayenne and bird eye chili hot pepper types can also be exploited further at lower production costs especially those incurred pest management.

This study also showed that fruit fly resistant genotypes do exist in Ugandan germplasm and can form a basis for breeding for resistance to the devastating pest. The FCM posted low infestation levels on hot pepper but its lack of preference of the genus does not mitigate the quarantine issues, as a single infested fruit in a sample can cause rejection of the consignment. As such, this lack of appeal of the genus can be a basis for protection of the peppers by teaming them with more preferred plant species in mixed cropping systems. On the other hand, highly susceptible hot pepper genotypes can act as trap crops for the fruit flies in crops where the pest is a big problem. Important to note is that generally the genotypes that had low fruit fly infestation also had low FCM infestation, the contrast also being true. Hence, the same fruit traits that favour fruit fly and FCM infestation of hot pepper are similar.

5.2 Conclusions There was much variation in performance of the hot pepper genotypes, in terms of resistance to fruit pests and yield performance. Genotypes CAP0408-12, UG-WE02-1014, UG-WE02- 0711, UG-EA06-0515 and UG-WE02-1608 were the most promising in terms of resistance to fruit flies albeit with low yields. Genotypes UG-WE02-1802, UG-WE02-1909, UG-CE01- 0401, UG-WE05-0607and UG-CE01-0805 had the highest yields but were more susceptible to fruit damaging pests. Fruit width and weight were the major fruit traits that influenced pest

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infestation of the genotypes. Generally, heavier and broader hot pepper fruits were more prone to infestation by fruit pests. The number of fruits per plant, fruit weight and width were the major traits that significantly contributed to hot pepper yield.

5.3 Recommendations I recommend that:

1. Genotypes, CAP0408-12, UG-WE02-1014, UG-WE02-0711, UG-EA06-0515 and UG- WE02-1608 to be utilized in breeding programs for resistance to fruit pests. 2. Genotypes, UG-WE02-1802, UG-WE02-1909, UG-CE01-0401, UG-WE05-0607 and UG- CE01-0805 should be included in breeding programs for their better yield and fruit quality traits. 3. Susceptible genotypes such as UG2-WE0808-26 can be used as trap crops for fruit flies. 4. Further evaluation of the genotypes for more seasons in different environments to gauge their yield and stability. 5. Further studies to establish chemical basis of resistance of the resistant genotypes.

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APPENDICES

Appendix 1.Pooled analysis of variance for pest infestation, fruit traits and yield for 48 hot pepper genotypes with pepper type as a covariate Mean squares Source of variation Df Pest infestation Fruit traits Yield DF (%) FFL (%) FCM (%) PF (N) FL (cm) FW (cm) Few (g) Yield (t/ha) MF (%) Pepper type 1 5.627ns 3.531 ns 0.01 ns 0.01 ns 0.00 ns 0.01 ns 31.28 ns 362.96 ns 0.22 ns Genotype 47 1378.31*** 416.11*** 0.50*** 0.70*** 7.71*** 3.81*** 43.77*** 2469.76*** 1121.96*** Season 1 36.83 ns 9576.85*** 10.18*** 0.48*** 5.82*** 3.94*** 65.83*** 48586.75*** 17933.35*** Genotype x Season 47 742.21*** 124.76** 0.587*** 0.19*** 0.44*** 0.05*** 4.10*** 1690.77*** 512.87*** Error 189 48524.39 108858.42 130.18 0.04 0.13 0.02 0.09 138.49 180.46 df=degrees of freedom, DF=damaged fruits, FFL=fruit fly infestation, FCM=false coddling moth infestation, PF=fruit penetration force, FL=fruit length, FW=fruit width, Few=fruit weight, MF=marketable fruits ns not significant; *significant (P < 0.05) ** highly significant (P < 0.01); *** highly significant (P < 0.001)

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Appendix 2.Correlation coefficients for the relationship between fruit pest infestation and fruit parameters of hot pepper genotypes in season 2017A evaluated at MUARIK

Damaged% FFL% FCM% No. L/F Few FL FW PF Damaged% - FFL% 0.29*** - FCM% 0.17* 0.52*** - No. L/F 0.27*** 0.38*** 0.28*** - Few 0.22** 0.66*** 0.59*** 0.36*** - FL -0.15 0.31*** 0.16 0.36*** 0.44*** -

FW 0.36*** 0.72*** 0.64*** 0.45*** 0.85*** 0.31*** - PF 0.23** 0.29*** 0.16 0.25** 0.29*** 0.29*** 0.35*** - Damaged% = damaged fruits, FFL%=fruits infested by fruit fly, FCM%=FCM infestation, No. L/F=number of fruit fly larvae per fruit, Few= average fruit weight, FL=fruit length, FW=fruit width, PF=penetration force *significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

Appendix 3.Correlation coefficients for the relationship between fruit pest infestation and fruit parameters of hot pepper genotypes in 2018B evaluated at MUARIK Damaged% FFL% FCM% No. L/F Few FL FW FWT PF Damaged% - FFL% 0.42*** - FCM% 0.06 0.01 - No. L/F 0.33*** 0.59*** 0.11 - Few 0.28*** 0.53*** 0.06 0.51*** - FL 0.06 0.23 0.06 0.16 0.56*** - FW 0.34*** 0.55*** 0.08 0.52*** 0.93*** 0.46*** - FWT 0.37*** 0.52*** 0.05 0.44*** 0.78*** 0.41*** 0.86*** - PF 0.27*** 0.23** -0.05 0.11 0.29*** 0.28*** 0.37*** 0.53*** - Damaged% = damaged fruits, FFL%=fruits infested by fruit fly, FCM%=FCM infestation, No.L/F=number of fruit fly larvae per fruit, Few= average fruit weight, FL=fruit length, FW=fruit width, PF=penetration force *significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

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Appendix 4. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes evaluated in season 2017A at MUAURIK Y(t/ha) No. F/P Few FW FL MF% Y(t/ha) No. F/P 0.23** - Few 0.56*** -0.37*** - FW 0.47*** -0.44*** 0.85*** - FL 0.37*** -0.29*** 0.44*** 0.31*** - MF% -0.14 0.47*** -0.43*** -0.57 0.06 - Y(t/ha)=yield, No.F/P=number of fruits per plant, Few=average fruit weight, FW=fruit width, FL=fruit length, MF%=marketable fruits (%) *significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

Appendix 5. Correlation coefficients for the relationship between yield and fruit traits of hot pepper genotypes evaluated in 2018B at MUARIK Y(t/ha) No. F/P Few FW FL FWT MF% Y(t/ha) - No. F/P 0.62*** - Few 0.38*** -0.29*** - FW 0.35*** -0.29*** 0.93*** - FL 0.31*** -0.13 0.56*** 0.46*** - FWT 0.33*** -0.20* 0.78*** 0.86*** 0.41*** - MF% 0.27*** 0.37*** -0.13 -0.15 -0.05 -0.19* - Y(t/ha)=yield, No.F/P=number of fruits per plant, Few=average fruit weight, FW=fruit width, FL=fruit length, FWT=fruit wall thickness, MF%=marketable fruits (%)

*significant (P < 0.05); ** highly significant (P < 0.01); *** highly significant (P < 0.001); the rest are non-significant

Appendix 6. Monthly weather data for Season 2017A (December 2016-June, 2017) hot pepper trial conducted in MUARIK. Month Rainfall (mm) Min. temp. ºC Max. temp. ºC Mean. temp. ºC December 25.2 17 36 26.5 January 17.8 16 35 25.5 February 30.2 16 33 24.5 March 12.8 17 32 24.5 April 7.0 17 32 24.5 May 7.8 18 30 24.0 June 7.0 15 31 23.0

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Appendix 7. Monthly weather data for 2018B (September 2017-March, 2018) hot pepper trial conducted in MUARIK. Month Rainfall (mm) Min. temp. ºC Max. temp. ºc Mean. temp. ºC September 6.4 17 31 24.0 October 57.0 17 32 24.5 November 34.0 16 31 23.5 December 0.0 17 32 24.5 January 0.2 16 29 22.5 February 0.0 16 28 22.0 March 38.6 16 31 23.5

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