DISTRIBUTION OF PARTHENIUM HYSTEROPHORUS L. AND ITS IMPACTS ON BIODIVERSITY AND AGRICULTURAL PRODUCTIVITY IN NYANDO SUB COUNTY, KISUMU COUNTY, KENYA

Murono Dorca Auma (B.ED) I56/CE/26446/2014

A Thesis Submitted in Partial Fulfillment of the Requirement for the Award of Degree of Master of Science (Plant Ecology) in the School of Pure and Applied Sciences of Kenyatta University

MAY, 2019

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DEDICATION

This research work is dedicated to my beloved husband and friend John Otieno Abuto and our dear sons Benard Abuto Otieno and Benjamin Jesse Otieno.

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ACKNOWLEDGEMENTS

I am grateful to God for His continued love and faithfulness in enabling me to go through the entire research work with strength, confidence and determination.

I am greatly indebted to my supervisors Dr. Emily Wabuyele, and Dr. Paul Muoria for their wise counsel, great support, intelligent criticism and advice during all phases of this research work.

Many thanks to Kadibo community farmers for receiving me open heartedly and making this research possible through their generous participation and input.

Data collection could not have been possible without the help of Augustine Baraza who participated in plant specimen collection in the field, Stephen Abuto who provided transport, Mwadime Nyange for helping with plant identification and Dickens Odeny for development of distribution map.

Lastly, I thank my family whose support has been remarkable and unwavering, including my dad Benjamin, mum Martina, my sons Bernard and Benjamin and my husband John

Abuto.

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TABLE OF CONTENTS

DECLARATION ...... ii DEDICATION...... iii ACKNOWLEDGEMENTS ...... iv TABLE OF CONTENTS ...... v LIST OF TABLES ...... viii LIST OF FIGURES ...... ix ABBREVIATIONS AND ACRONYMS ...... x ABSTRACT ...... xi CHAPTER ONE ...... 1 INTRODUCTION ...... 1 1.1 Background information ...... 1 1.2 Statement of the problem ...... 2 1.3 Justification to the study ...... 3 1.4 Research questions ...... 3 1.5 Research hypotheses ...... 4 1.6 Objectives of the study ...... 4 1.6.1 General objectives ...... 4 1.6.2 Specific objectives ...... 4 CHAPTER TWO ...... 5 LITERATURE REVIEW ...... 5 2.1 General trends of plant invasions ...... 5 2.2 Impacts of invasive alien species ...... 6 2.3 Characteristics of invasive plants ...... 9 2.4 Origin and distribution of P. hysterophorus ...... 9 2.5 Description of P. hysterophorus ...... 10 2.6 Economic importance of P. hysterophorus ...... 12 2.7 Adverse effects of P. hysterophorus ...... 14 2.8 Control strategies for P. hysterophorus ...... 15 2.9 Ecological significance of soil seed bank for invasive alien species ...... 17 2.10 Seed dormancy and seed bank longevity of P. hysterophorus ...... 29 CHAPTER THREE ...... 21 MATERIALS AND METHODS ...... 21 3.1 Study area ...... 21 3.2 Sampling method ...... 23 3.2.1 Distributionof P. hysterophorus in Nyando subcounty ...... 23 3.2.2 Impacts of P. hysterophorus density on herbaceous species diversity...... 23

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3.2.3 Determination of soil seed bank across the land use types ...... 24 3.2.4 Survey of the farmers perception on the impact of P. hysterophorus ...... 25 3.3 Data management and analysis ...... 26 CHAPTER FOUR ...... 27 RESULTS ...... 27 4.1 Species composition ...... 27 4.2 Distribution of P. hysterophorus in Nyando Sub County...... 287 4.3 Impact of P. hysterophorus density on herbaceous species diversity and density ...... 30 4.3.1 Impact of P. hysterophorus density on species richness ...... 30 4.3.2 Impact of P. hysterophorus density on species diversity ...... 31 4.3.3 Effects of P. hysterophorus density on the density of medicinal plant species… ..... 31 4.4 The size of P. hysterophorus seeds in the various land use types ...... 32 4.5 Perception of local people on the impacts of invasion on crop and livestock productivity...... 32 4.5.1 Awareness of P. hysterophorus existence and invasion ...... 32 4.5.2 Impact of P. hysterophorus on crop production ...... 33 4.5.3 Impact of P. hysterophorus on livestock production ...... 34 CHAPTER FIVE ...... 36 DISCUSSION, CONCLUSIONS AND RECOMMENDATIONS ...... 36 5.1 DISCUSSION ...... 36 5.1.1 Spartial distribution of P. hysterophorus ...... 36 5.1.2 Impacts of P. hysterophorus on species diversity, richness and density of herbaceous plant species...... 38 5.1.3 Parthenium hysterophorus seed abundance in the various land use types ...... 42 5.1.4 Impact of P. hysterophorus invasion on crop and livestock productivity ...... 43 5.2 CONCLUSIONS...... 45 5.3 RECOMMENDATIONS...... 45 5.4 FUTURE RESEARCH PROSPECTS ...... 46 REFERENCES ...... 47 APPENDICES ...... 61 Appendix 1 Questionnaire ...... 61 Appendix 2 Medicinal uses of the plant species found in the study area ...... 64 Appendix 3 Publication associated with this research work ...... 65 Appendix 4 National Commission for Science, Technology and Innovation Research Permit ...... 66

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LIST OF TABLES

Table 4.1: Plant species found in the study area ...... 27

Table 4.2: Mean density of P. hysterophorus in different land use types and sites ...... 30

Table 4.3: Mean diversity of plant species in different land use types and sites ...... 31

Table 4.4: Mean number of seedlings that germinated per volume of soil ...... 32

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LIST OF FIGURES

Figure 2.1: Mature P. hysterophorus plant ...... 11

Figure 2.2: Life cycle of P. hysterophorus plant ...... 12

Figure 3.1: Map of Nyando Sub County ...... 21

Figure 4.1: Plant families recorded in the study area ...... 28

Figure 4.2: Distribution map of P. hysterophorus in Nyando Sub County ...... 29

Figure 4.3: Comparison of mean density of P. hysterophorus in the land use types ...... 30

Figure 4.4: Crop land invaded by P. hysterophorus weed ...... 34

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ABBREVIATIONS AND ACRONYMS

ANOVA Analysis of Variance GPS Geographic Positioning System IBM International Business Machine IUCN International Union for Conservation of Nature KEDDP Kisumu East District Development Plan SPSS Statistical package for social sciences UNEP United Nations Environmental Programme

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ABSTRACT

Parthenium hysterophorus L. has been considered to be one of the worst invasive weed in Asia, Africa and Australia. The weed threatens natural and agro ecosystems in over 30 countries worldwide. In Kenya, the weed was first reported in the early 1970s in coffee plantations in Kiambu County and has since spread to more areas in and around Nairobi, central, western and eastern Kenya. Thus, the aim of this study was to evaluate the extent of invasion and impact of P. hysterophorus on plant species diversity and agricultural productivity in Nyando Sub County of Kisumu County. Distribution was determined as presence of the weed in the sampled areas. Geographical co-ordinates were recorded using a hand held geographical positioning system (GPS) receiver. Fifteen transects were established randomly and vegetation surveys conducted. Soil samples were collected for the seed bank study. A total of 210 respondents were interviewed using semi structured, open ended questionnaires to assess the impact of P. hysterophorus invasion on agricultural production. GPS data on presence of P. hysterophorus was loaded into ArcGPS 9.1 software to develop point distribution map. One-way ANOVA was used to assess difference in mean density of P. hysterophorus and to test difference in size of the seeds among various land use types (p ≤ 0.05). Effect of P. hysterophorus density on species diversity, richness and density of other herbaceous plant species was evaluated by correlation analysis. Data from perception survey was summarized using descriptive statistics. Parthenium hysterophorus was found to be widely distributed. There was a negative correlation between the density of the weed and species diversity (r = -0.075, p = 0.029) and richness (r = -0.924, p = 0.001). This indicated that where P. hysterophorus density was high, species diversity, and richness was low. There was a significant difference in the abundance of seeds in soils from various land use types (F = 3.88, p = 0.017). Most respondents reported a negative effect of P. hysterophorus on livestock and crop production. This study recommends the need for increased awareness of P. hysterophorus, its impacts and possible solutions among the local people, researchers and extension workers. Appropriate control measures should be applied urgently.

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CHAPTER ONE

INTRODUCTION

1.1 Background information

Invasive alien species are defined as non-indigenous species that colonize a particular habitat and negatively impact on it ecologically, environmentally or economically

(Schoonover, 2010). A plant species may become invasive if it can out-compete other species for resources such as nutrients, light, water or food (Weidenhamer and Callaway,

2010).

Biological invasion constitutes one of the leading threats to natural ecosystems and biodiversity in general (Jabeen et al., 2015). A number of authors have described the impacts of invasive alien species on agriculture, forestry, fisheries, and other human enterprises and as well as on human health (Patel, 2011; Kushwaha and Maurya, 2012;

Saini et al., 2014). One such invasive alien plant species is Parthenium hysterophorus which is widely distributed and belongs to the family Asteraceae or Compositae (Bagchi et al., 2016). Parthenium hysterophorus is an aggressive, annual or ephemeral herbaceous weed of tropical and subtropical regions. The weed is commonly known variously as star weed, fever weed, bitter weed, white top, congress grass and wild fever few among other names (Joshi et al., 2016).

Parthenium hysterophorus has invaded the natural ecosystems throughout the world and in so doing threatened losses in agricultural productivity (Masum et al., 2013). The weed has strong potential to spread due to allelopathy and has since invaded a range of habitats in Kenya (Wabuyele et al., 2014). According to Evans (1997), the distribution of P. hysterophorus indicates severe threat for the ecosystem in biodiversity hotspot areas. In

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Kenya P. hysterophorus is thought to have been introduced in the 1970s in coffee plantations in Kiambu County (Njoroge, 1991; McConnachie et al., 2010). The weed has since spread to other parts like Nairobi, Lake Victoria basin, Nyeri, Nanyuki, Mwea and

Kibwezi where it has been recorded in a range of habitats including drainage trenches, dumpsites, construction sites, residential areas, game reserves and crop fields (Wabuyele et al., 2014).

1.2 Statement of the problem

Kenya has experienced a number of biological invasions some of which have had significant impacts on socio-economic well-being of the people (Keil, 1988). Notable examples include the water hyacinth (Eichhornia crassipes), mathenge (Prosopis juliflora), tickberry (Lantana camara) and most recently congress grass (P. hysterophorus). Like many locations in Western Kenya, Kisumu County has been invaded by P. hysterophorus. In addition to causing hay fever and allergic reactions in man and livestock, the P. hysterophorus weed has been reported to exert allelopathic effects which suppress growth and establishment of associated plant species and subsequent decrease in forage and habitat for animals (Bagchi et al., 2016).

Parthenium hysterophorus has also been reported to cause reduction in species diversity and subsequent formation of pure stands of P. hysterophorus. These ultimately change the vegetation structure that inevitably alters both biotic and abiotic interactions (Saini et al., 2014) and changes in species diversity. In spite of these adverse effects of P. hysterophorus, there is limited information regarding its geographical distribution, rate of expansion, socio-economic and environmental impacts in Kisumu County in general and Nyando Sub County in particular. This study was designed to generate data on threat

3 posed by P. hysterophorus to native biodiversity and habitats, agriculture and the overall economic impact in Nyando Sub County of Kisumu County.

1.3. Justification to the study

Parthenium hysterophorus weed has been spreading rapidly in both natural and agricultural ecosystems in Kenya since it was first reported in Kiambu County in the

1970s (Njoroge, 1991). According to Wabuyele et al., (2014), the weed has spread to many parts of the country and exerted negative impact on the biodiversity and socio- economic well-being of the people. Due to the likely allergic reactions in humans and livestock, farmers are likely to incur higher input of cultural weed control (hand weeding) to manage the weed as well as a reduction in meat and milk quality from their livestock. There is need to create awareness of the danger posed by continued invasion of the weed among policy makers, resource managers, and the general public to ensure vigilance and prevent imminent disaster (Wabuyele et al., 2014). Findings from this study will provide baseline for efficient control and management of the weed and enhance socio-economic development in Nyando Sub County and Kenya in general.

1.4 Research questions

i. What is the extent of invasion of P. hysterophorus in Nyando Sub County?

ii. How does the density of P. hysterophorus weed affect plant species richness,

diversity and density of herbaceous flora of the invaded areas?

iii. What is the size of P. hysterophorus seeds in the various land use types in

Nyando Sub County?

iv. Does invasion by P. hysterophorus weed affect agricultural productivity in

Nyando Sub County?

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1.5 Research hypotheses

i. Parthenium hysterophorus is not widely distributed in Nyando Sub-County.

ii. Density of P. hysterophorus does not affect species richness, diversity and

density of herbaceous flora of the invaded areas.

iii. The size of P. hysterophorus seeds in various land use types in Nyando Sub-

County is not the same.

iv. Parthenium hysterophorus invasion has no impact on agricultural productivity in

Nyando Sub County.

1.6 Objectives

1.6.1 General objectives

To investigate the distribution, ecological and economic impacts of P. hysterophorus in

Nyando Sub-County, Kisumu County, Kenya.

1.6.2 Specific objectives

i. To map the distribution of P.hysterophorus in Nyando Sub County.

ii. To assess the effects of P. hysterophorus density on species richness, diversity

and density of herbaceous flora.

iii. To determine the abundance of P. hysterophorus seeds in the various land use

types in Nyando Sub County.

iv. To document the local people’s perception on the impacts of P. hysterophorus

invasion on crop and livestock productivity.

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CHAPTER TWO

LITERATURE REVIEW

2.1 General trends of plant invasions

According to Mack et al. (2000) plant invasions are mostly associated with disturbed habitats. Many invasive alien species are adapted to low-elevation agricultural or urban environments which are highly disturbed and are rich in nutrients. Many invasive species colonize areas with same climatic conditions as their native ranges, though their success depends on their ability to compete with indigenous species and colonize new habitats.

Activities such as construction of roads cause substantial amount of disturbance on natural communities, exposing soil, clearing natural vegetation, and altering the drainage pattern. This results in extensive movement and compaction of soil and introduction of a new seed bank from exotic species (Forman, 2000). Such habitats become conducive to invasive species colonization, which are often highly adapted to disturbance (Fox and

Fox, 1986). Roads facilitate invasion by acting as movement corridors, aiding in seed dispersal and bringing reproducing plants in contact with natural habitats (Haseler, 1976;

Watkins et al., 2003).

In their study, Richards et al. (2006) and Nicotra et al. (2010) found that plasticity of key functional traits of species may be particularly beneficial during the invasion process and to all plants facing a changing climate. Phenotypic plasticity is the ability of a particular genotype to express a range of phenotypes across different environmental conditions

(Van Kleunen and Fischer, 2005; Kelly et al., 2012). Therefore, phenotypic plasticity enhances niche breadth (Sultan, 2001; Richards et al., 2005) enabling invaders to succeed under novel conditions without large amounts of genetic diversity. In North

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America a study on 75 phylogenetically related species pairs classified as invasive were found to be more plastic in a wide variety of morphological and physiological traits than native non-invasive species. This greater plasticity of invasive species could imply that these species are more likely to be successful invaders or that plastic genotypes within species were selected during the invasion process (Sexton et al., 2002; Parker et al.,

2003).

2.2 Impacts of invasive alien species

Impacts of invasive alien species may be economic, ecological or social in nature

(Heather and Jeffrey, 2007). Economic impact results into direct consequence to humans, leading to monetary losses. Ecological impacts on the other hand affect ecosystem structure and function, often referring to loss of biodiversity or unique habitats (Gallardo et al., 2015). Social impacts focus predominantly on human health and safety, recreational opportunities, cultural heritage and aspects of social structure (Heather and

Jeffreys, 2007).

Ecological impacts of invasive alien species on ecosystems vary depending on the invading species, the extent of invasion and the vulnerability of the species and ecosystems being invaded. Loss and degradation of biodiversity caused by invasive alien species cut across all levels of biological organization from the genetic and population level, through the species, community and ecosystem levels, and may involve major alterations to the physical habitat, water quality, essential resources and ecological resources (UNEP, 2005). These impacts according to Wilcove et al. (1998) can vary in terms of the lapse time between the initial introduction and subsequent spread of an invasive alien species, its severity of impacts (Levine, 2000) and the livelihood of

7 synergistic interactions with other threatening processes (McNeely et al., 2001). These alien invaders reduce the abundance of native species through hybridization, predation, parasitism or competition for resources and may lead to alteration of community structure and ecosystem processes such as nutrient cycling and energy flow of a particular ecosystem (Meyerson et al., 2004).

Economic effects of invasive alien species vary with both market and non-market impacts. The cost and benefit of invasive alien species according to Ciruna et al. (2004) are mixed because alien species are often a source of income, food or livelihood for local communities and often support economic activities. A study by Zalavetas (2000) on the economic impacts of salt cedar (Tamarix sp.) invasion found that this plant species affected municipal, agricultural, hydro electrical power generation and river recreation sectors resulting into market and nonmarket impacts. Elsewhere in Asia, Pomacea canalicuta (Golden apple snail) was introduced to be cultured as a high protein food source for local consumption as well for export. It has since invaded rice agro- ecosystems and has spread into extensive irrigation networks, feeding voraciously on rice seedlings. This led to actual production losses amounting to between 70,000 -

100,000 tons of paddy valued at $12.5 – 17.8 million in 1990 (UNEP, 2005).

Socially, invasive plant species pose a major threat to the livelihoods of the people who live in the areas they colonize. They restrict access to natural resources that people need to sustain their lielihood leading to decreased income and rising levels of poverty

(Scalera et al., 2012). Invasive plant species lead to decline in crop yields and destruction of land used for grazing livestock, these results in lower food security increasing hunger and malnutrition (UNEP, 2005). In addition invasive alien plant species can lead to harsh

8 living conditions through reduction of available resources like water and lack of access to recreational activities. Furthermore pathways and tracks can be blocked by invasive plants, making it difficult to access important facilities such as health centres (Gallardo et al., 2015). Most families in invaded areas have abandoned their land when it becomes impossible to cultivate. This may lead to competition of limited natural resources resulting in conflict between communities or force people to migrate to new areas which are unfavourable (Ciruna et al., 2004). Most weeding is done by women and children due to lack of funds to employ necessary labour. This may have adverse effect on childrens education if they spend less time in school to work in the farms (Gallardo et al., 2015).

2.3 Characteristics of invasive plants

All species have certain characteristics that determine their ability to live and co-exist in a particular area (Ciruna et al., 2004). One or more of these traits will determine how successful a given species is relative to others (Rebbeca et al., 2012). Invasive plants have characteristics that enable them to survive in areas where they are introduced. Most of them are generalist and have ability to survive in a variety of locations, habitats and conditions. These characteristics have been reviewed extensively by many authors

(Prentis et al., 2008; Davidson, 2011). Elton (1958) reported that most successful non- native species would have traits that promote effective reproduction and dispersal, superior competitive ability and ability to occupy vacant niches.

According to Viisteensaari et al. (2000) invasive plants must occur in large-enough populations in areas of natural or semi-natural vegetation for them to produce a significant change in vegetation composition, structure or ecosystem process. Studies show that invasive alien plants have a faster germination rate and a large size as

9 compared to the native plants (Pysek and Richardson, 2007; Grotkopp et al., 2002; Van

Kleunen et al., 2011). More often than not, invasive plants are prolific and capable of producing many offspring that eventually take over a particular area (Holle and

Simberloff, 2005). Many authors have also identified fecundity as important correlate of invasiveness in the invaded range (Mason et al., 2008; Moravcova et al., 2010; Burns et al., 2013; Jelbert et al., 2015).

2.4 Origin and distribution of P. hysterophorus

Parthenium hysterophorus is a member of the tribe Heliantheae, sub-tribe Ambrosiinae of the family Asteraceae, an extremely diverse family with a cosmopolitan distribution

(Sankaran, 2008; Wunderlin and Hansen, 2011). It is a noxious plant which inhabits many parts of the world, in addition to its native range in North and South America

(Wunderlin and Hansen, 2011). The weed is thought to have been introduced into Asia,

Africa and Oceania as contamination of wheat and pasture seeds (Bagchi et al., 2016).

Currently, it is widely distributed in several tropical and subtropical countries across the world, including Australia, Pacific Islands, Sri Lanka, Bangladesh, China, Ethiopia,

Israel, Mozambique, Vietnam, Taiwan, Pakistan, Madagascar, Somalia, Zimbabwe,

India, South Africa and Nepal amongst others (Saini et al., 2014).

In Kenya, the weed was first reported in the 1970s in coffee plantations in the central highlands of Kenya (Njoroge, 1991; McConnachie et al., 2010). According to Wabuyele et al. (2014), two ‘Parthenium hotspots’ were recognized: parts of Nairobi and its environs, with weed densities ranging from low to high mostly along recently upgraded roads such as those leading from Nairobi to central, western and coastal Kenya as well as

Namanga, a border town with Tanzania. The second ‘hotspot’ was identified in the Lake

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Victoria Basin in the former Western and Nyanza provinces where medium density infestations of the weed were found. Isolated young populations were found in former eastern province around Mwea and Kibwezi, a zone which is eco-climatically less suitable to P. hysterophorus infestation (Wabuyele et al., 2014).

2.5 Description of P. hysterophorus

Parthenium hysterophorus is a herbaceous species that produces a basal rosette of leaves during the early stages of growth and averages 0.5-2.0m tall, sometimes reaching heights of over 2m (Tamado et al., 2002). The stems are greenish, longitudinally fluted and often branched at maturity. The leaves are simple, alternately positioned with petioles of up to

2cm long; older leaves are comparatively large and deeply lobed. The large lower leaves are spread on the ground like a carpet, without allowing any vegetation underneath. Both the stems and leaves are covered with fine soft hairs (Adkins and Shabbir, 2014). The plant bears numerous small flower-heads occuring in clusters at the tips of the branches.

The inflorescence is a panicle (Roy and Shaik, 2013), bearing several tiny white flowers in the center and is surrounded by two rows of small green bracts (Figure 2.1).

Major morphological and ecological features that contribute to the invasiveness of this plant are its ability to adapt to a wide range of agro-climatic and soil conditions. It produces allelochemicals and large numbers of seeds about (10,000-25,000 per plant)

(Gnanavel, 2013). Seeds are small (1-2mm in diameter) and light in weight (50mg) and can be transported long distance by water and wind (Bekeko, 2013).

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Figure 2.1: Mature P. hysterophorus plant. Source: (Weed Management Guide, 2003)

Seed dormancy in unfavorable environmental conditions, a large viable seed bank

(subsoil and above soil), and intense regenerative capability make P. hysterophorus a highly fecund weed (Kohli et al., 2011). Moreover, the weed is very competitive and has been reported to outcompete Cenchrus ciliaris a C4 pasture grass with increase at elevated concentrations of atmospheric CO2 (Khan et al., 2018). This phenomenon is typical of C3 and C4 plants when grown in atmospheres enriched with CO2 (Gnanavel,

2013). The weed grows anytime of the year in different stages of its life cycle and can complete four to five generations per year (Kushwaha and Maurya, 2012; Saini, et al.,

2014) (Figure 2.2).

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Parthenium hysterophorus weed grows and flourishes on black, alkaline clay soils. It is also able to grow on a wide range of other soils, from sandy loams to clay loams from sea level up to 2400m (CIASNET, 2010). Parthenium hysterophorus is usually found in naturally disturbed areas and those that have poor ground cover, such as cleared lands, wastelands and overgrazed pastures. Drought following reduced pasture cover creates an ideal condition for the weed to establish itself. Other common habitats for this weed include forestlands, agricultural areas, urban areas, industrial areas, roadsides, play grounds and residential plots amongst others (Adkins and Shabbir, 2014).

Figure 2.2: Life cycle of P. hysterophorus plant. Source: (Saini et al., 2014).

2.6 Economic importance of P. hysterophorus

Allelopathy can be used to increase crop production at minimal expenses as allelochemicals can be exploited as herbicides, insecticides, nematicides, fungicides and growth regulators providing defence against herbivorous predators (Datta and Saxena

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2001). Use of compost from P. hysterophorus weed enhances soil moisture level more than nitrogen phosphorous and potassium (N.P.K) fertilisers alone (Kishor et al., 2010).

Parthenium hysterophorus was used by Javaid (2008) as green manure for production of maize and beans. Javaid (2008) also found that when used as mulch, P.hysterophorus has smothering effect on weeds as it restricts photosynthesis, conserves soil moisture, lower surface temperature, fertilize the soil and improve the soil quality.

Industrial uses of P. hysterophorus have been reported in the literature. A decoction of the plant has been used in West Indies as a remedy against ulcerated sores, certain skin disease, facial neuralgia, fever and anaemia (Bhatt et al., 2012). A preparation with ginger is effective as a remedy for migraines during the early pain phase (Kuhn and

Winston, 2007). Active chemical constituents like parthenin are pharmacologically active against neuralgia and certain types of rheumatism. In a laboratory experiment, it was shown that sub-lethal doses of parthenin exhibit antitumor activity in mice (Ramos et al., 2002). Parthenium hysterophorus was reported as a good source of biogas, and also can be used as green manure (Jagadisha et al., 1998).

Therefore, despite being obnoxious, P. hysterophorus can prove to be a valuable asset when exploited by proper means and technology. Lata et al., (2007) found out that sulphuric acid treated carbonized P. hysterophorus is a cost effective, easily available and low-cost adsorbent for the removal of Nickel (II) chloride from dilute aqueous solution. Furthermore, phosphoric acid treated P. hysterophorus can also be considered as potential adsorbent for methylene blue removal from dilute aqueous solution (Lata et al., 2007).

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2.7 Adverse effects of P. hysterophorus

Parthenium hysterophorus is considered as one of the most dangerous terrestrial weeds because of its harmful effects to both humans and to biodiversity. It has been reported to cause a total habitat change in native Australian grasslands, open woodlands, river banks, and flood plains (Lakshmi and Srinivas, 2007). In invaded areas P.hysterophorus changes the habitat by replacing neighboring flora and changing soil characteristics

(Temesgen et al., 2017). Parthenium hysterophorus plant contains chemicals, like parthenin, hysterin, hymenin, and ambrosin, and due to the presence of these chemicals, the weed exerts strong allelopathic effects on different crops. Furthermore, allelochemicals from root exudates might change soil pH to slightly acidic or neutral conditions (Bwohmik et al., 2007).

Parthenium hysterophorus is an aggressive colonizer of disturbed areas causing major negative impacts on pasture and crops. It competes strongly with crops like sunflower and affects nodulation in legumes due to inhibition of nitrogen fixing and nitrifying bacteria namely species of Actomycetes, Azospirillum, Rhizobium and Azotobacter.

Parthenium hysterophorus has been reported to cause yield loses in several crops like field mustard, wild cabbage, soy bean, perennial rye grass, rice, common bean, cultivated radish, chick pea, common wheat, mung bean and maize (Yadav and Chauhan, 1998;

Oudhia, 2000a, b; Tamado et al., 2002). The weed acts as an alternative host for the insect mealy bug and many diseases caused by viruses in crops. In India, the weed was found to invade sugarcane plantation, vegetable and rice fields causing a yield decline of up to 40% (Singh et al., 2004). In Australia, P. hysterophorus has invaded around

170,000 km2 of prime grazing land in Queensland, causing economic losses of around

$16.8 million per year to the pasture industry (Chippendale and Panetta, 1994).

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The hepatoxic allelochemical parthenin causes both acute and chronic toxicity, reduction in milk yield, tainting in mutton and bitter taste in milk. Consumption of large amounts of P. hysterophorus causes anorexia, alopecia, diarrhea and in severe cases death of cattle (Narasimhan et al., 1997). Moreover, the toxic parthenin and phenolic acids in the pollen grains, airborne dried plant parts and roots of P. hysterophorus can cause allergies such as contact dermatitis, hay fever, asthma, bronchitis, irritation and cracking of skin and stomach pain in human (Agarwal and D’Souza 2009). Frequent contact with the plant stock or its pollen has been reported to cause dermatitis with pronounced skin lesions on animals including horses and cattle.

2.8 Control strategies for P. hysterophorus

Parthenium hysterophorus spreads rapidly due to its strong reproductive ability and persistent seed bank thus preventing its spread is the most cost-effective management strategy. Physical methods such as ploughing deeply, uprooting by hand or burning in the infested areas can limit the spread of this plant though they are not effective because of related health impacts such as asthma and hay fever among others (Navie et al., 1996).

Parthenium hysterophorus should be uprooted before flowering and seed setting to reduce wide spread dispersal (Wiesner et al., 2007; Goodall et al., 2010). Physical control is suitable for use on a small scale like in agricultural and residential area thus not an economical method of controlling large infestations (Haseler, 1976).

Chemical control of P. hysterophorus has been reported by several authors (Tadesse et al., 2010; Goodall et al., 2010; Reddy et al., 2007). Effective chemical control has been reported in Australia (Navie et al., 1996) when applied at suitable growth stages and rates. Herbicides like norflurazon (C12H9CIF3N3O), clomazone (C12H14CINO2),

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fluometuron (C10H11F3N2O) and trifloxysulfuron (C14H13F3N5NaO6S) are very effective in controlling post-emergence of P. hysterophorus (Reddy et al., 2007). Using herbicides to control P. hysterophorus is harzadous to the environment. Furthermore, P. hysterophorus has been reported to develop resistance against chemicals such as atrazine

2, 4-D and thus not economically feasible to small holder farmers (Ramesh et al., 2003).

Singh et al. (2004) considered exploitation of competitive plants like Cassia sericea,

Amaranthus spinosus, Tephrosia purpurea, Hyptis suaveolens, and Sida spinosa, which are capable of suppressing the weed in their natural habitat. In India studies show that crop rotation using marigold (Tagetes spp) during the rainy season instead of usual crop has been found effective in reducing spread of P. hysterophorus in cultivated areas

(Pandey, 1997). Aqueous and methanolic extracts of Datura metel and Withania somnifera, can limit the germination and growth of P. hysterophorus (Anjam et al.,

2005).

Biological control of weeds by plant pathogens has gained acceptance as safe environmentally beneficial method applicable to agroecosystems (Kore, 2006). Emphasis has been put on the control of P. hysterophorus through various biocontrol agents such as microbial pathogens, insects and botanicals (Wiesner et al., 2007; Batish et al., 2007).

Studies by Bhowmik et al. (2007) showed that successful control of P. hysterophorus was achieved by leaf feeding beetle Zygograma bicolarata (Pallister) and stem galling moth Epiblema strenuana (Walker). Some fungal species such as those of Alternaria,

Fusarium and Colletotrichum capsici have been reported to control the spread of P. hysterophorus (Lakshimi and Srinivas, 2007). According to Dhileepan (2009) there is no single management option adequate to control P. hysterophorus across all habitats,

17 therefore there is need to integrate various management option with classical biological control as a core management option.

2.9 Ecological significance of soil seed bank for invasive alien species

Soil seed bank is the totality of viable seeds available within a soil profile and on the surface (Qiuyan et al., 2011). According to Wanga et al. (2005) all living seeds present in the soil or mixed to debris constitute the soil seed bank. Soil seed bank represent a form of dispersal in space and time which allows the colonization of new localities

(Thompson and Grime, 1979). Viable seeds have been found in or on the soil for different length of time and seasons Milberg and Anderson (1997), in different quantities

Thompson and Grime (1979), at different depths Grundy et al. (2003) and in different states of dormancy (Walck et al., 2005; Finch-Savage and Leubner-Metzger, 2006).

According to Benvenuti (2007) seeds in the soil bank may occur in or on the surface but on many occasions there is continuity between seeds at the surface, partly buried and those completely buried in the soil. Seed banks comprise of both dormant and non- dormant seeds Qiuyan et al. (2011) which enhances the probability of persistence of a species at a particular area when germination conditions are unfavorable or in absence of additional seed rain (Baskin and Baskin, 1998). Plants differ in the duration their seeds remain in the soil even among seeds of the same cohort (Saatkamp, et al., 2014).

Thompson and Grime (1979) proposed a system of soil seed classification based on the study of seasonal dynamics and the longevity of seed banks.

In their classification, species viable for less than one year are classified as transient seed banks. They don’t present dormancy and are dispersed in time for short periods during

18 the year (Garwood, 1989). Persistent soil seed banks are plant species whose seeds remain viable for more than one year. They are further divided into short term persistence for seeds which remain viable for one to five years and long persistence for those that remain viable for more than five years (Csontos and Tamas, 2003). In the context of plant invasions this classification is useful as it allows predicting how long invasion and native species may persist in the soil as a potential source of propagules in the absence of additional introductions (Saatkamp et al., 2014).

Studies examining the seed bank of communities invaded by a single invasive species show that the contribution of seeds of invasive species to invaded seed banks varies from minimal to large. Increased number of invasive seeds to the seed bank may have important implications as any natural or anthropogenic disturbance is likely to promote the germination of seeds of the invader, resulting in the rapid dominance of the invader in the vegetation and seed bank (Vosse et al., 2008; Gioria and Osborne, 2010). In addition, high densities of invasive seeds may alter the viability and germination patterns of seed of native species thus affecting the susceptibility of invaded communities to secondary invasions (Gioria et al., 2011).

Alien plant invasions generally reduce the density of the seed bank of plants in the invaded communities, whereas the effect on species richness may be negligible (Gioria and Psek, 2016). In their study on seed bank richness and density for 18 invasive species,

Gioria et al. (2011) found that invasions by large herbaceous species cause the greatest changes in resident, native and alien seed banks, thus reducing the species richness and density of both native and alien seed banks. Such a strong impact is likely to indicate the changes occurring in the above ground vegetation for both native and alien species and

19 also suggesting that limiting dispersal may be an important mechanism preventing the spread of seeds from neighboring community species.

Several studies have also reported changes in species composition associated with long term invasions even where differences in species richness or density were not evident

(Gaertner et al., 2011; Abella et al., 2013). In addition, seed bank composition in disturbed areas is more similar to vegetation composition than that in relatively undisturbed ecosystem because of an overrepresentation of small persistent seeds, which tend to increase along gradients of disturbance (Fenner and Thompson 2005). Effects of invasive species on the seed bank are also likely to increase with residence time Psyek et al. (2005) for species that have ability to change the ecosystem and soil properties which may further affect seed bank dynamics via alterations in seed production, dormancy and germination dynamics (Gaertner et al., 2011).

2.10. Seed dormancy and seed bank longevity of P. hysterophorus

Parthenium hysterophorus has persistent seed bank with seed viability greater than 50% after more than 2 years in the soil (Tamado et al., 2002). Parthenium hysterophorus seeds have the ability to undergo dormancy. Seeds near the soil surface are rarely viable beyond 2 years while undisturbed, buried seeds can stay dormant for a longer period of up to six years. Dormancy mechanism prevents untimely germination in climates where rainfall is irregular.

Seed bank size and persistence has implication several years beyond a reduction in P. hysterophorus populations. In support of this view, Butler (1984) reported that the germination of P. hysterophorus weed seeds declined from 66% after one year of burial

20 to 12% after burial for 2 years. According to Navie et al. (1998) there was 74% seed viability after 2 years’ burial and the predicted half-life of the P. hysterophorus weed seeds was about 6 years. Tamado et al. (2002) reported that the viability of P. hysterophorus seeds was >50% after 26 months of burial in the soil and the half-life of seeds in the soil was approximately 3 – 4 years. In addition, the absence of primary dormancy mechanism was found in the seeds McFadyen (1992) but according to Navie et al. (1998) the initial inhibition of germination was shown in freshly shed seeds.

Seasonal variations significantly affect seed dormancy and seed bank longevity of P. hysterophorus seeds. Warm conditions have been reported by Long et al. (2008) to promote the reproductive ability of P. hysterophorus, such as increasing seed production and seed fill percentages, promoting dormant seed production and producing seeds with capacities to live longer in the soil seed bank. Elsewhere Karlsson (2008) reported that cold stratification reduced dormancy characteristics of P. hysterophorus seeds.

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CHAPTER THREE

MATERIALS AND METHODS

3.1 Study area

The study was undertaken in western part of Nyando Sub-County (formerly known as

Kadibo Division) of Kisumu County (Figure 3.1). Nyando Sub-County lies between longitude 33o 20’ – 35o 20’East and latitude 0o 20’ – 0o 50’South. The area covers a total of approximately 163 square kilometers and a population of about 73,227 persons,

(KNBS, 2013). The area receives a mean annual rainfall of 1000mm and mean annual temperature of 20oC (KCIDP, 2013).

0 0 0 0 34 40 E 0 0 35 00 E 34 50 E

MUHORONI KISUMU TOWN EAST

S

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NYAKACH S

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Figure 3.1: Map of Nyando Sub-County. Source: Nyando Base Map – Humanitarian Response, 2009)

22

The main drainage river channels include river Nyando and Obuso. The area is dominated by black cotton soils which develop deep cracks in the dry season that allow a lot of rain water to penetrate at the beginning of the rainy season. During the onset of the rainy season, the soils expand, cracks close and water cannot further infiltrate into the soil leading to flooding of the plain terrain. In addition, the Sub-County is located on the low ridges where rivers occasionally break into causing loss of property and human life due to flooding (KEDDP, 2008).

A large number of households in the study area are engaged in agro-pastoral practices and fishing as the main stay economic activities. In the farmlands, various crops are grown and these include rice, cotton, sugarcane, tomato, maize and sorghum among others. In addition, the small-scale pastoralists rear cattle, goats, sheep and pigs.

Indigenous chicken and ducks are kept for subsistence purposes in nearly all the households (KCIDP, 2013).

In this study, three sites were chosen for data collection, namely Rabuor, Nyamware and

Bwanda regions of Nyando Sub-County (Figure 3.1). Rabuor is located close to the

Nairobi-Kisumu highway and has many shopping centers. Thus many residents of

Rabuor are business people (traders) while a few are involved in small scale agriculture among other economic activities. Bwanda is located further away from the highway and experiences less flooding as compared to Nyamware, on the shores of Lake Victoria.

Residents of Bwanda practice small scale agriculture and trade as main stay economic activity. Many farmers from Bwanda and Rabuor graze their cattle in Nyamware due to the presence of extensive pasture lands, rivers and nearness to the lake. Nyamware is dominated by crop farming and livestock grazing. Due to low amounts of rainfall, most

23 farmers practice irrigation farming. The area experiences flooding due to its location where many rivers break into the lake.

3.2 Sampling method

The survey was carried out from 1st November 2016 to 31st March 2017 (after the short rain) in the three sampling sites. These sites were chosen on the basis of accessibility, area invaded by P. hysterophorus and habitat heterogeneity. This study consisted of four stages: establishment of spatial distribution of P. hysterophorus, sampling for herbaceous plant species, soil seed bank analysis and perception survey of local people.

3.2.1 Distribution of P. hysterophorus in Nyando Sub County

Mapping of P. hysterophorus was done to assess its distribution pattern and to characterize the land use types invaded by the weed. A section of the Nairobi-Kisumu highway (between Alendu and Korowe) was used as the main transect and from it six feeder roads (three from each side of the road) measuring approximate distance of 10km were selected. Along each feeder road, stops were made where P. hysterophorus was present and geographic coordinates recorded using a hand-held GPS receiver. Locality data on the distribution of P. hysterophorus was loaded in to ArcGIS 9.1 software to develop point distribution map.

3.2.2 Impact of P. hysterophorus density on herbaceous species diversity

Based on visual observation of land use types, five major land use types were selected using stratified random sampling method (Mueller-Dombois and Ellenberg 1974) namely: river bank, residential, pastureland, roadside and cropland. For each land use type, three sampling sites with an area greater than one hectare and covered by P.

24 hysterophorus weed were selected. A ten meter (10m) long transect was established in each sampling site and along it, ten quadrats systematically laid where P. hysterophorus and other herbaceous plant species were identified, counted and recorded. Geographic positioning system (GPS) readings (altitude, latitude and longitude) for each sampling site was taken using GPS channel 12 reader in order to locate the global position of each quadrat as well as the sampling site. Plant species collected from the quadrats were identified in the field with the help of a plant taxonomist from East African Herbarium.

For species that could not be determined in the field, voucher specimens were collected, pressed, dried and transported to the East African Herbarium at the Kenya National

Museum for identification.

3.2.3 Determination of soil seed bank across the land use types

Soil samples were collected from the land use types selected during herbaceous vegetation survey in November 2016. This period represents the end of the growing season (i.e. after seed production event) for most of the herbaceous species. In each site, two kilograms (2kg) of soil was collected i.e. two hundred grams (200gms) of soil sample was taken from each of the ten quadrats along each transect at a depth of upto

15cm using a soil auger. The soil samples from each site were mixed in plastic bags to form a composite sample in order to capture the spatial heterogeneity of the seed distribution in the soil.

From the 2kg of soil collected from each site, 500gms of soil sample was measured and later transported to a greenhouse in Rabuor for germination experiment. In the green house, soil samples were spread thinly on shallow trays (20 × 25 × 6cm; width/length/height) that were distributed randomly on a bench. All the trays were

25 watered daily to maintain the soil moisture content close to field condition. The trays were observed regularly and newly emerging P. hysterophorus seedlings recorded by date as they germinated after every two weeks and discarded. Each month, the soil samples were stirred to provide optimum conditions for seed germination. The experiment took three months with the assumption that some seeds might take long to germinate.

3.2.4 Survey of farmers’ perception on the impact of P. hysterophorus

A single visit formal survey was used to gather information on the impact of P. hysterophorus on livestock and crop production. With the aid of a structured, open- ended questionnaire (Appendix 1), information was collected on the overall impact of P. hysterophorus using purposive sampling procedure. Respondents were selected based on their awareness of P. hysterophorus invasion and its impact on their livestock and crops.

Selection of informants was based on:

(i) Informants length of stay in the study area i.e. residents who had stayed in the

area for more than ten years.

(ii) Willingness of the local inhabitant to participate in the study.

(iii) Informants age’-preferably to be above 30 years.

The questionnaire was prepared in English and verbally translated in Kiswahili and Luo where necessary. Farmers were shown the live sample plant and asked for information regarding P. hysterophorus invasion in the area. A pre-test of the prepared questionnaire was practiced before the start of the actual survey to achieve effective communication for the needed information by the selected farmers. Informants were interviewed to understand the impact of P. hysterophorus invasion on crops and livestock.

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3.3 Data management and analysis

All the plant species identified in this study were ranked according to their families and data presented in form of tables and bar graphs. Locality data on the presence of P. hysterophorus was loaded in to ArcGIS 9.1 software to develop point distribution map.

Density of plant species in each of the sampling sites was computed using the formula:

total number of plant species in all quadrats Density = total number of quadrats used

Diversity of the plant species per site was calculated using Simpson diversity index (Bibi and Ali, 2013).

푛(푛 − 1) 퐷 = 1 − ( ) 푁(푁 − 1)

Where, n = is the total number of organisms of a particular species

N = is the total number of organisms in all species

Effect of P. hysterophorus density on species diversity, richness and density of other herbaceous plants was evaluated by correlation analysis. In these analyses, P. hysterophorus density was considered as explanatory variable and other attributes as response variables. One-way ANOVA, followed by Tukeys HSD test was used to determine significant differences in the mean values of variables of vegetation data

(richness, diversity and density) and in soil seed bank abundance among various land use types (p ≤ 0.05). Data from perception survey was summarized using descriptive statistics. International Business Machine Statistical Package for Social Sciences (IBM-

SPSS) version 20 was used for all statistical analyses.

27

CHAPTER FOUR

RESULTS

4.1 Species composition

A total of 25 herbaceous plant species belonging to 12 families were recorded in the three sampling sites.

Table 4.1: Plant species found in the study area

Species name Family Parthenium hysterophorus Linn. Asteraceae Schkuhria piñata Lam. Asteraceae Xanthium strumarium Linn. Asteraceae Flaveria trinervia Spreng. Asteraceae Tridax procumbens Linn. Asteraceae Tagetes minuta Linn. Asteraceae Sphaeranthus steetzii Olive and Hien. Asteraceae Gomphrena celosioides Mart. Amaranthaceae Amaranthus spinosus Linn. Amaranthaceae Alternanthera pungens Kunth. Amaranthaceae Clitoria ternatea Linn. Fabaceae Alysicarpus vaginalis Linn. Fabaceae Sida acuta Burm.f. Malvaceae Corchorus trilocularis Linn. Malvaceae Corchorus olitorius Linn. Malvaceae Hibiscus panduriformis Burm.f. Malvaceae Euphorbia hirta Linn. Euphobiaceae Euphorbia indica Lam. Euphobiaceae Cycnium tubulosum L.f. Orobanchaceae Tribullus terrestris Linn. Zygophyllaceae Datura stramonium Linn. Solanaceae Commelina benghalensis Linn. Commelinaceae Hygrophila auriculata Schumach. Acanthaceae Centella asiatica Linn. Apiaceae Ipomea aquatic Forssk. Convolvulaceae

Family Asteraceae had the highest number of species while Orobanchaceae,

Zygophyllaceae, Solanaceae, Commelinaceae, Acanthaceae, Convolvulaceae and

Apiaceae had the least number of species as shown in figure 4.1.

28

30

25

20

15

10

Percentage species plant of Percentage 5

0

Family

Figure 4.1: Plant families recorded in the study area.

4.2 Distribution of P. hysterophorus in Nyando Sub-County

Parthenium hysterophorus weed was found to be extensively distributed among the five land use types viz., cropland, river bank, road side, pastureland and residential areas

(Figure 4.2). There was significant variation in the mean density of P. hysterophorus among the five different land use types with high density recorded in cropland and roadside while residential areas had the lowest density (p ≤ 0.05) (Figure 4.3 and Table

4.2). The highest densities of P. hysterophorus weed were recorded in the roadside and cropland in Rabour and Nyamware with mean densities of 34.00±0.577 and 26.33±3.18, respectively. The least density (2.33±2.60) was recorded in residential area in Bwanda

(Table 4.2). Similarly, there was a significant variation in the mean density of the weed from the three sampling areas (p ≤ 0.05). For instance, a comparative analysis of the three sampling sites revealed statistically significant difference in the mean densities of

29

P. hysterophorus weed in pastureland, cropland, residential area and river bank (p ≤

0.05). On the other hand, there was no statistical difference in the mean density of P. hysterophorus in the roadside among the three sampling sites (p ≤ 0.05) (Table 4.2).

Figure 4.2: Distribution map of P. hysterophorus in Nyando Sub-County (Source of inset maps: Nyando Base Map – Humanitarian Response, 2009).

30

2 40 35 30 25 Bwanda 20 Nyamware

P. hysterophorus hysterophorus /m P. Rabuor 15 10

5 Density of Density of 0 Roadside Pastureland Cropland Residential River bank Land use types

Figure 4.3: Comparison of mean density of P. hysterophorus in the land use types.

Table 4.2: Mean density of P. hysterophorus in different land use types and sites

Density of P. hysterophorus /m2 Sites Roadside Pastureland Cropland Residential River bank Bwanda 21.67±2.19cA 15.33±2.33cB 20.00±2.65bA 4.33±2.60bD 6.00±2.31bC Nyamware 25.00±2.52bA 24.33±3.38aA 26.33±3.18aA 9.67±1.86aC 12.33±3.60aB Rabuor 34.00±0.577aA 18.67±2.33bC 21.33±1.45bB 9.67±1.76aD 6.00±3.21bE

Results were expressed as Mean±Standard Eror of Mean (SEM). Means followed by different lowercase and uppercase superscripts within the same column and row respectively are statistically different.

4.3 Impact of P. hysterophorus density on herbaceous species richness, diversity and density

4.3.1 Impact of P. hysterophorus density on species richness

There was a significant negative relationship between density of P. hysterophorus weed and species richness (r = -0.924, p < 0.001, df=14). This implied that an increase in the density of P. hysterophorus weed led to the decrease in the number of other plant species

31 in the sampling areas, hence the negative correlation values. Sites which had low density of P. hysterophorus had more herbaceous plant species.

4.3.2 Impact of P. hysterophorus density on species diversity

Species diversity varied significantly among the land use types (F = 8.378, p < 0.014, df=14). The highest value was recorded along the river banks (0.62±0.12) while the least was recorded in crop land (0.03±0.01) (table 4.3). According to the correlation analysis, sites which recorded higher density of P. hysterophorus had low diversity in herbaceous plant species (r = -0.075, p= 0.029). Similarly, sites which had lower number of P. hysterophorus weed recorded higher diversity in herbaceous plant species.

Table 4.3: Mean diversity of plant species in different land use types and sites

Diversity of plant species /m2 Sites Roadside Pastureland Cropland Residential River bank Bwanda 0.37±0.07aAB 0.16±0.06bB 0.12±0.05bB 0.28±0.09abB 0.62±0.12aA

Nyamware 0.22±0.08aAB 0.11±0.04bB 0.03±0.01bB 0.16±0.06bB 0.33±0.09aB

Rabuor 0.34±0.06aA 0.37±0.07aA 0.16±0.09aA 0.47±0.10aA 0.45±0.08aA

Results were expressed as Mean±Standard Eror of Mean (SEM). Means followed by different lowercase and uppercase superscripts within the same column and row respectively are statistically different at p < 0.05 by one way ANOVA and Tukey’s HSD post hoc test

4.3.3 Effect of P. hysterophorus density on the density of herbaceous plant species

The 25 plant species identified alongside P. hysterophorus (table 4.1) have been reported to possess medicinal properties as shown in Appendix II. Out of these plant species, three species namely Schkuhria pinnata, Gomphrena celosiodes and Tagetes minuta were selected for correlation analysis. Results showed a negative relationship between the densities of P. hysterophorus and other herbaceous plant species. This implies that an

32 increase in P. hysterophorus led to a decrease in the number of Schkuhria pinnata (r =

0.392, p = 0.026), Gomphrena celosiodes (r = -0.032, p = 0.016) and Tagetes minuta (r =

0.675, p = 0.0322).

4.4 Size of P. hysterophorus seed bank in the various land use types

The analysis of mean seed abundance showed that there was a statistical significant difference in the number of seedlings that germinated from the land use types (F = 3.88, df=4, p = 0.017). Parthenium hysterophorus seedlings were notably abundant in the roadside (19.60±2.62) and agricultural land (19.40±2.7) than in soils from the river bank

(11.60±2.4) and residential area (9.00±0.71) (table 4.4).

Table 4.4: Mean seed abundance in the land use types

Land Use Mean±SE Mean Crop land 19.33±3.67ab Pasture land 15.67±2.03ab Residential 9.33±1.20b River bank 11.67±1.67ab Roadside 21.00±2.08a

Results were expressed as Mean±Standard Eror of Mean (SEM). Means followed by different lowercase and uppercase superscripts within the same column and row respectively are statistically different at p < 0.05 by one way ANOVA and Tukey’s HSD post hoc test

4.5 Perception of local people on the impacts of P. hysterophorus invasion on crop and livestock productivity

Using a questionnaire a total of 210 respondents (70 respondents from each site) were sampled from Rabuor, Bwanda and Nyamware. Farmers expressed their views on the impacts of P. hysterophorus invasion on crop and livestock productivity.

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4.5.1 Awareness of Parthenium hysterophorus existence and invasion

All the respondents were aware of the presence of the weed. However, larger proportion

(84.3%) did not know the name of the weed in their local language while a few (15.7%) knew the local name of the weed. Some call it ‘Mafuwa’ (flowers), ‘Akech’ (bitter) or

Buya’ (troublesome weed). Fourty five point five percent (45.5%) of the respondents first noted this weed in cropland, 33.0% by the roadside, 10.5% noted it in pastureland,

6.5% in the residential area while 4.5% first noted it in other land use types (fallow land, abandoned buildings, along rivers, in markets areas and damp sites). All the respondents felt that the weed was rapidly expanding in its range in the area.

Seventy two percent (72.0%) of the respondents did not see the value of the weed and were of the opinion that P. hysterophorus was not useful in anyway. Only, 28.0% felt that the weed is useful. Some of the uses of the weed stated by the residents were improvement of soil moisture retention and fodder for animals. Other uses of P. hysterophorus according to the respondents include sweeping (brooms), mulching, herbal medicine for stomachache and as a ‘‘carpet’’ in market grounds (yards) during muddy days.

4.5.2 Impact P. hysterophorus on crop production

Sorghum, maize, rice, beans and other crops were cultivated by 47.5%, 25.0%, 12.5%,

8.5% and 6.5% of the respondents, respectively. The study established that P. hysterophorus was most common in sorghum cropland (49.5%) than in other crop lands.

Due to the presence of P. hysterophorus, some respondents (48.0%) experienced increased demand for farm labour especially management of the weed which is done through weeding, slashing, burning and uprooting. Forty percent (40.0%) noted yield

34 reduction whereas 12.0% of the respondents experienced health problems like asthma and itching of the skin when they come in contact with the weed.

Most of the residents (89.0%) reported that crop production per unit area had declined during the preceding 10 years due to the expansion of P. hysterophorus range in the area.

Eleven percent (11.0%) of the respondents however had not realized the decline in crop production. Residents stated that the presence of P. hysterophorus in their village and in their farmland had an impact on the quantity of crops (43.5%), quality (18.5%), income level (35.0%) and welfare of the society as well as on the movement of the people

(3.0%) (Figure 4.9).

Figure 4.4: Cropland invaded by P. hysterophorus weed (in white flowers) in Nyando Sub Coutny

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4.5.3 Impacts of P. hysterophorus weed on livestock production

Apart from P. hysterophorus weed, a number of other weed species were found dominating the grazing land. These included Gomphrena celosioides, Xanthium strumarium, Datura stramonium, Amaranthus spinosus and Alternanthera pungens.

Respondents (56.0%) stated that other weeds dominated their grazing land while 44.0% stated that their grazing land is dominated by P. hysterophorus weed.

A larger portion of the respondents (76.0%) stated that the weed is not consumed by livestock whereas 24.0% reported that the weed is consumed by livestock especially goats. Some of the respondents (38.5%) attributed the decline in cattle productivity to the presence of P. hysterophorus weed. Moreover, 22.0% of the respondents reported a decline in their income level, 22.0% complained of a lot of time and cost of labour consumed while weeding out the weed. Fifteen point five percent (17.5%) realized a decline in the quantity and quality of livestock product especially in the amount and taste of meat and milk respectively.

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CHAPTER FIVE

DISCUSSION, CONCLUSIONS AND RECOMMENDATIONS

5.1 Discussion

5.1.1 Spatial distribution of P. hysterophorus

The current study shows that most parts of Nyando Sub-County has been invaded by P. hysterophorus. This weed was mainly found in cropland, roadside, residential area, pasture land and along rivers. These findings are consistent with those of Kilewa and

Rashid (2015), who reported a higher degree of P. hysterophorus invasion in roadside, cropland and pastureland in Tanzania. A study carried out by Karki (2009) in Nepal reported high densities of P. hysterophorus along roadsides, industrial areas and non- cultivated farmland. Oudhia (2001) also reported a similar pattern of invasion in a phytosociological study of the weeds of the rainy season in Raipur in India where he found P. hysterophorus dominating the vegetation.

Density of P. hysterophorus varied significantly in the study area. These might be attribured to the difference in ecological conditions among the three sampling sites.

Rabuor which lies along the Nairobi-Kisumu highway had high densities of P. hysterophorus. This can be attributed to soil disturbance from road mantainance activities which facilitate establishment of P. hysterophorus. According to Fumanal et al.

2008b disturbing the soil surface not only stimulate the germination of weed seeds but also increase the number of leaves, stem biomass and the seed production emerging individuals. Roads function as prime habitats and coridors for invasive plant species.

This is because roads are usually well drained, open habitats that are frequently disturbed by maintainance activities (Hulme, 2003). They are also polluted by heavy metals and fertilizers (Jodoin et al., 2008).

37

Likewise Nyamware which lies along the shores of L. Victoria had high densities of P. hysterophorus. This area is associated with flooding, increased animal movement and crop farming through irrigation. These factors might have contributed to greater abundances of P. hysterophorus in Nyamware. This is because dispersal mechanism of

P. hysterophorus which is mainly through flooding, animal dung, animal movement, wind and movement of machinery facilitate the rapid spread of P. hysterophorus from one place to another (Lusweti et al., 2011). In addition, Crawley (1997) reported that periodic disturbance in the form of floods disperse seeds, prepare them for germination and provide seedbed thus promoting invasion of new territory. Bwanda which lies between Rabuor and Nyamware (away from the highway and the lake) had low densities of P. hysterophorus and this can be attributed to less soil disturbance.

Auld et al. (1983) stated that local dispersal of P. hysterophorus seeds occur by wind and water while motor vehicle, machinery, crop and pasture seeds are responsible for long distance dispersal. The rapid spread of P. hysterophorus in Nyando Sub County might also be as a result of high reproductive potential, enormous seed bank and short life cycle

(Dalip et al., 2013). In addition, the seeds of P. hysterophorus weed have been reported to remain viable for a long time and survive under very harsh environmental conditions

(Williams and Groves, 1980). Moreover, levels of invasion might have also been favored due to the allelopathic effects of P. hysterophorus which inhibits the germination and growth of other plant species (Riaz and Javaid 2009).

Based on impact of P. hysterophorus reported in this study, the distribution of this weed in Nyando Sub-County is to the detriment of both natural and agroecosystems.

According to Wise et al. 2007 P. hysterophorus competes strongly with crops such as

38 sorghum, suppresses yield as well as contaminating grains. This weed is also unpalatable to livestock and when fed on in large amounts, the animals may suffer from gastrointestinal irritation which may lead to diarrhoea. Furthermore, once dominant, P. hysterophorus weed persists as pure stand and this adversely affects the growth of other plant species (Gnanavel, 2013). Therefore persistence of the weed in the region poses a severe threat to the biodiversity and agricultural productivity.

5.1.2 Impact of P. hysterophorus density on diversity, richness and density of herbaceous plant species

A total of 25 herbaceous plant species belonging to 12 families were recorded in the study area. This is in consonance with study of Ortega et al. (2004) who reported high densities and dominance of different invasive exotic plant species in Montana, USA.

This is due to their better establishment success than their indigenous counterparts.

Globally, several studies have revealed the aggressiveness of P. hysterophorus weed.

Similar trend was observed in the current study where species diversity, richness and density decreased significantly with the increase in P. hysterophorus density. For instance, sites which recorded higher density of the weed had the lowest plant species diversity and richness. Similarly, sites which had lower number of P. hysterophorus recorded higher plant species diversity and richness. This can be attributed to the fact that P. hysterophorus weed grows faster, has a short life cycle, greater reproductive ability, competitive ability and allelopathy that makes it a successful invader of non- native habitats (Grice, 2006). This is in line with findings by Dalip et al., (2013) who indicated that P. hysterophorus weed easily occupied new locations and often substituted native plant species resulting in a serious damage to biodiversity.

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In Ethiopia, Ayana et al. (2011) noted that within a few years of introduction of P. hysterophorus weed into Awash National Park, there was a decline of 69% in stand density of herbaceous species. The reduction of species richness and diversity with increasing density of P. hysterophorus has been well elaborated by Navie et al. (1996).

The same author also reported that P. hysterophorus takes the form of a rosette during the early stages and requires suitable area to establish. The rosette spreads rapidly near the ground and interferes with the emergence of other seedlings through allelopathy. The stem elongates later and branches at the apex. Together with its high growth rate, the weed becomes competitive and develops the ability to exclude the growth of other species (Navie et al., 1996).

Gomphrena celosiodes, Xanthium strumonium, Alternanthera pungens and Tagetes minuta were the most dominant herbaceous species as they were present in most of the sampling sites. This might be because the plants have strong competitive vigor with P. hysterophorus and are also prolific producers of light seeds which are easily blown by wind (Timsina, 2007). In addition these species produce many thorny bracts that easily attach on human clothing and hairs of animals thus ensuring their dispersal and dominance in Nyando Sub-County (Dalip et al., 2013).

The study also found that plant species such as Alysicarpus vaginalis, Clitoria ternatea and Corchorus trilocularis were less dominant in many sampling sites. This might be attributed to the negative effects of P. hysterophorus invasion as a result of its allelopathic properties and competitive replacement (Timsina, 2007). According to

Gilfedder and Kirkpatrick (1993) and Gentle and Duggin (1998), the abundance of individual native threatened plant species are negatively correlated with the weed species

40 that have invaded their habitat. The decline in species diversity and richness with successive increase in the P. hysterophorus infestation level is an indicator that the community heterogeneity has significantly and negatively been affected. This might be related to rapid dispersal by animals and other human activities. The current results are in agreement with the findings of McFadyen (1992) and Chipendale and Panetta (1994) who reported a total habitat change in native Australian grassland, open woodlands, river banks and flood plains.

The present study found a negative relationship between density of P. hysterophorus weed and density of medicinal plant species namely, Tagetes minuta, Gomphrena celosioides and Schkuhria pinnata. This would imply that these species are not equipped with the versatile characteristics that P. hysterophorus weed has and as a result they cannot withstand strong competition with it. These results support the work of Shabbir and Bajwa (2007) who reported a decline in Artemisia scoparia, Tribulus terrestris and

Cannabis sativa in Pakistan due to increase in P. hysterophorus density. Similarly,

Mahadevappa et al. (2001) reported that P. hysterophorus had become a curse for the natural herbs of Chhattisgarh plains of India.

In a study on the impact of alien species in India, MacDonald et al. (1991) found that alien plant invaders shade out indigenous species and reduce their recruitment. The present study gives strong evidence to show that P. hysterophorus negatively affected the density of other herbaceous flora by inhibiting their recruitment and regeneration possibly due to increased allelopathic influence. Tadele (2002) reported that P. hysterophorus releases phytotoxin substances like parthenin, hysterin and ambrosin into its immediate environment which highly inhibits germination and growth of several plant

41 species. This is because allelochemicals released from P. hysterophorus are capable of changing the physiochemical characteristics of the soil by affecting the moisture content, temperature, pH, organic matter, carbon, nitrogen, phosphorous and soil microbial activity (Mulatu et al., 2009).

From this study, it can be postulated that an increase in P. hysterophorus invasion may lead to changes in the structure and species composition of vegetation thereby affecting the availability of resources. When an alien plant species invades, the nature of the resources that are available and the spatial and temporal patterns of resource availability can all be altered (Brandt and Muller, 1995). Rice and Emery (2003) also reported a change in the structure and composition of native plant community due to introduction of an exotic plant species. Some of the plant species identified alongside P. hysterophorus are used by the Luo Community in Kenya as herbal medicine (Orwa, 2002; Geissler et al., 2002). For instance, the leaves of Tagetes minuta are used to treat wounds, nematodes and tick infestation in livestock (Maema et al., 2016) while Gomphrena celosiodes has been used to cure skin diseases, jaundice and malaria (Mansour et al.,

2016). The extracts of Schkuhria pinnata are used as an arbotifacient and contraceptive

(Lewu and Afolayan, 2009). Thus, changes in the density and structure of the indigenous vegetation undoubtedly have ramification for the human communities that depend on them.

5.1.3 Parthenium hysterophorus seed abundance in the various land use types

The soil seed bank study was conducted for the purpose of gaining information that would assist in determining the land use type that is more vulnerable to P. hysterophorus invasion. High invasion of P. hysterophorus in different land use types in Nyando Sub-

42

County might be due to its ecological and morphological characteristics which enable it to adapt to a wide climatic and soil conditions, photo insensitivity and drought tolerance

(Khan et al., 2014). Additionally, the weed produces large number of seeds of up to 25

000, which are small in size and light in weight (Lorraine and Lin, 2015), thus the seeds can spread easily over long distances through moving water, wind, animal and human dispersal (Abdulkerimute and Legesse, 2016).

Of the five land use types, road side had the highest seed densities and this can be attributed to soil disturbance due to road construction and movement of vehicles. Initial occurrence of P. hysterophorus in a new area usually occurs along roadsides and it’s from this foothold that it spreads to other habitats (Haseler, 1976). Blackmore and

Charlton (2011) reported that roadsides are more commonly invaded and established by

P. hysterophorus than open spaces and farm lands. Thus, high densities of P. hysterophorus alongside roads might have helped in the dispersal and spread of P. hysterophorus into other land use types in Nyando Sub-County. Residential areas recorded the lowest seed bank density and this might be attributed to frequent management of the weed through slashing and burning.

Parthenium hysterophorus may therefore attain the status of most dominating weed in

Nyando Sub-County and the surrounding areas in the near future. This is because once it invades; the weed dominates after a few years and continues to persist as pure stand until its managed (Shabbir and Bajwa, 2007). In addition, invasion of different land use types by an exotic weed P. hysterophorus is a phenomenon which could lead to permanent changes in the structure of indigenous plant community around Nyando Sub-County as observed in other studies (Holway, 2002). There is therefore an urgent need of integrated

43

P. hysterophorus management strategy to stop further spread of this alien weed in the region.

5.1.4 Impacts of P. hysterophorus invasion on crop and livestock productivity

The impacts of P. hysterophorus on agriculture have been documented by several authors (Kumar et al., 2014; Muli, 2014; Hundessa and Belachew, 2016). Socio- economic survey in Nyando-Sub County established that P. hysterophorus was a common weed since all respondents recognized it. Most respondents reported the use of physical methods to control the weed through weeding, slashing, and uprooting. These require frequent operations on a single crop field in each season therefore expensive to the farmer (Bhan et al., 1997). Furthermore, weeding is a time-consuming activity and exposes the farmers to the detrimental health effect of P. hysterophorus namely contact dermatitis, hay fever, broncitis and asthma (Patel, 2011). Studies show that no single method has been satisfactory in the control of P. hysterophorus (mechanical, chemical and biological) thus integrated approaches are warranted to restrict the invasion of this weed by combining more than one option (Belachew and Tesema, 2012).

This research has also established that P. hysterophorus weed invasion negatively affect crop production in Nyando Sub-County. Most respondents revealed that due to P. hysterophorus weed, there are intensive labour requirements since the farms have to be weeded severally. Furthermore, reduction in crop yield especially maize and sorghum was noted. This result is in agreement with the findings of Muli (2014) who reported that

P. hysterophorus weed invasion reduced the yield of maize, beans and sorghum in

Nyando Sub-County of Kisumu County. The same author also reported increased farm labour expenditure in Nyando Sub-County by 6 253 Kenya shillings per year per acre.

44

Crop losses are mainly due to allelopathatic effects (Demissie et al., 2013) and high competitive ability (Netsere and Mendesil, 2011).

The effect of P. hysterophorus on livestock production is similarly diverse, affecting grazing land, animal health, milk and meat quality. The current study reported a perceived decline in livestock production and quality of milk and meat. This can be attributed to the fact that P. hysterophorus releases chemicals that inhibit the germination and growth of pasture grasses and other plants (Dalip et al., 2013) thus reduces feed supply for animals. In addition, P. hysterophorus weed causes reduction in milk

Gnanavel (2013) and reduces milk quality by tainting it with parthenin toxin

(Chippendale and Panetta, 1994). This research is also in agreement with a study by Muli

(2014) who reported a decline in milk production in Nyando Sub-County of Kisumu

County. Furthermore, presence of other weeds like Xanthium strumarium, Alternanthera pungens and Gomphrena celosiodes which are thorny have reduced the animal feeds since most animals tend to avoid areas dominated by these weeds. Parthenium hysterophorus invasion and dominance in grazing land was reported to cause heavy loses to cattle industry in Queensland (Chippendale and Panetta, 1994).

Although majority of the respondents reported negative impacts from P. hysterophorus, some found it useful in sweeping, mulching and as a mud “carpet” in market grounds

(yards) during muddy days. These three uses are detrimental as they contribute to the propagation of P. hysterophorus seeds thus increasing dispersal from one place to another. This demonstrates the need for awareness campaigns in Nyando Sub-County to sensitize the residents on the adverse effects of P. hysterophorus. Research by Strathie et al. (2011) showed that developing countries lack knowledge of the impending threat of

45

P. hysterophorus weed despite the weeds rapid spread in Africa and globally. Therefore, there is need to initiate awareness campaigns about P. hysterophorus weed in Nyando

Sub-County and the country in general.

5.2 Conclusions

High densities of P. hysterophorus were recorded in most land use types namely river bank, pasture land, crop land, road side and residential areas. The study has also revealed that ecosystems in Nyando Sub County are threatened by P. hysterophorus which has led to decrease in species richness, diversity and density of other herbaceous flora.

Nyamware recorded the highest P. hysterophorus seed abundance among the sampling sites while roadside had the highest P. hysterophorus seeds among the land use types.

Nyando Sub County has realized a decline in economic development due to invasion of

P. hysterophorus weed which was found to reduce the grazing area leading to reduction in the quality and quantity of milk and meat products. Furthermore, the weed has reduced the crop yield and increased labour expenses. Thus the outcome of this survey includes the realization of P. hysterophorus as a problem of national significance for

Kenya concurring with the reports of it as a major weed.

5.3 Recommendations

From this study’s findings, the following recommendations are suggested:

i. There is need for urgent control measures to be taken by local communities and

relevant authorities control the spread of P. hysterophorus and mitigate impacts on

species and ecosystems.

46

ii. There is need to increase awareness of P. hysterophorus, its impacts and mitigation

measures among the local people, other scientists, government and non-

government organizations.

5.4 Future research prospects

i. More studies should be conducted in different seasons and in different locations

to establish the effect of time and space on P. hysterophorus. iii. Quantitative studies should be undertaken to estimate agricultural losses associated

with P. hysterophorus in Kenya.

47

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APPENDICES

Appendix 1: Questionnaire

Part 1: General Information on Respondents

1. Residence......

2. Land ownership a. Leased b. Registered owner......

3. Gender (Sex) a. Male…………………………...... b. Female......

4. Age......

5. Length of residence in the study area...... years

Part ІІ: Socio-economic information on P. hysterophorus.

Section A: Impact on biodiversity

1. Do you know P. hysterophorus weed? a. Yes b. No

2. Do you have a local name for the weed?

3. In which land use type did it first appear? (please specify) a. Residential area b. Pastureland c. Roadside d. Cropland e. Others

4. Would you say P. hysterophorus weed is expanding or shrinking in your area?

5. What management practices have you applied to address the problem? a. Chemical control b. Physical control

6. Is the P. hysterophorus plant useful to you in any way? a. Yes b. No

7. If yes, what are they?

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a. Increase fertility of soil b. Improves soil moisture c. Used as fodder for animals d. Control soil erosion e. Others (please specify)

Section B: Crop production

1. What crops do you grow on your farm? a. Rice b. Maize c. Beans d. Sorghum e. Others (please specify)

2. In which of the croplands is P. hysterophorus weed common? a. Rice b. Maize c. Beans d. Sorghum e. Others (please specify)

3. What major impacts did you observe due to the presence of P. hysterophorus weed? a. Intensive labor b. Yield reduction c. Health problem d. Others (please specify)

4. Do you think that production per unit area has declined since the last 10 years due to the expansion of P. hysterophorus? a. Yes b. No

5. In your opinion does the presence of P. hysterophorus weeds in your village and in your farmland has an impact on the: a. Quality of crop b. Quantity of crop c. Income level and welfare of the society d. Movement of people e. Others (please specify

Section C: Livestock production

1. Is there a grazing land currently in your village? a. Yes b. No

2. Which plant species dominate the grazing lands? a) P. hysterophorus weeds

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b) Grass c) Others (please specify) 3. Is P. hysterophorus plant consumed by livestock?

4. What are some of the negative impacts caused by P. hysterophorus on livestock? a. Cattle productivity declines b. Quality of cattle product declines c. Declines the income level of the family d. Take too much labor and time of the family e. It affects the taste of their products f. Others (please specify)

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Appendix 2: Medicinal uses of the plant species found in the study area

Species name Family Medicinal uses and references Parthenium Treatment of fever, diarrhea, neurologic disorder, hysterophorus Asteraceae dysentery and malaria (Marwat et al., 2015). Arbortifacient and contraceptive (Lewu and Schkuhria pinata Asteraceae Afolayan, 2009). Xanthium strumarium Asteraceae Treats painful urination (Kane, 2014). Flaveria trinervia Asteraceae Treatment of wounds (Umadevi et al., 2006) Treats dysentery, diarrhoea and prevents hair loss Tridax procumbens Asteraceae (Maldhure, 2015). Treatment of wounds, control nematodes and ticks in Tagetes minuta Asteraceae livestock (Maema et al., 2016). Sphaeranthus steetzii Asteraceae Relieves bloat in cattle (Sori et al., 2004). Gomphrena Amaranthaceae Treatment of skin diseases, jaundice and malaria celosioides (Mansour et al., 2016). Amaranthus spinosus Amaranthaceae Treatment of obesity (Ediriweera, 2007). Alternanthera pungens Amaranthaceae Treatment of gonorrhea (Ahmed et al., 2013). Clitoria ternatea Fabaceae Treatment of peptic ulcer (Ediriweera, 2007) Alysicarpus vaginalis Fabaceae Treatment of skin allergy (Sharma et al., 2013) Sida acuta Malvaceae Treatment of neuralgia (Ediriweera, 2007). Corchorus trilocularis Malvaceae Treatment of syphilis (Muhammad and Khan, 2008). Corchorus olitorius Malvaceae Treatment of diabetes melittus (Ediriweera, 2007). Hibiscus pandoriformis Malvaceae Treatment of skin disease (Suthari et al., 2014). Euphorbia hirta Euphobiaceae Treatment of renal calculi (Ediriweera, 2007). Treatment of renal calculi, dysuria and bronchial Euphorbia indica Euphobiaceae asthma (Ediriweera, 2007). Used as an abortifacient, cures stomachache Cycnium tubulosum Orobanchaceae (Cherotich, 2011). Treatment of dysuria and renal calculi (Ediriweera, Tribullus terrestris Zygophyllaceae 2007). Treatment of rheumatism, gout, wounds, boils and Datura stramarium Solanaceae abscesses (Lewu and Afolayan, 2009). Commelina Commelinaceae Ease child birth, treats ringworm, headache, blood benghalensis clotting and typhoid (Jiofack et al., 2010). Hygrophila auriculata Acanthaceae Treatment of dropsy (Suthari et al., 2014). Centella asiatica Apiaceae Increase memory power (Ediriweera, 2007). Cures jaundice, nervous debility, nose bleeding, diabetes and high blood pressure (Malakar et al., Ipomea aquatica Convolvulaceae 2015).

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Appendix 3: Publication associated with this research work

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Appendix 4: National Commission for Science, Technology and Innovation Research Permit