Research consultancy

EFFICACY OF COW DUNG ASH AND CHILLI PEPPER POWDER IN CONTROLLING BEAN BRUCHID IN STORED BEANS (Phaseolus vulgaris)

CHAPTER ONE

INTRODUCTION

1.1 Background of the study

The global population is projected to reach 8.5 billion in 2030, 9.7 billion in 2050, and 10.9 billion in 2100 (Blakeney, 2019; UN, 2019). The rapidly increasing population in many developing countries has been attributed to decreasing death rates, and reduced infant mortality rates, among others (UN, 2019). The population of Latin America and the Caribbean tripled between 1950 and 2019, projected to reach 768 million in 2058. Australia and New Zealand, home to 30 million people in 2019, could see their population grow to 38 million in 2050 and 49 million in 2100 (UN, 2019). By 2100, Asia and Africa are expected to be home to a combined population of 9 billion out of the projected 11.0 billion people inhabiting Earth (FAO, 2014). In East Africa, Kenya’s population is projected to reach 66.45 million and increase further to 91.58 million in 2050 and 125.45 million in 2100 (UN, 2019). Uganda’s population is projected to be 130 million people by 2050 and estimated to reach 167 million by the end of the century, surpassing that of Egypt, the second largest populated country in Africa (Kaddodo Betty & PPD, 2011).

The demand for food by the rapidly increasing population remains a global concern for humankind (Kumar & Kalita, 2017). Many countries and other concerned organizations like World Food Programme and Food and Agricultural Organization have been directed towards raising food production to cater to the increasing population (Debouck et al., 2021; FAO et al., 2021). Despite the efforts of concerned bodies, storage pests have affected vital food (Affognon et al., 2015). Therefore, there is a need to meet the challenges of food demand, and the production of legume crops such as beans plays a central role in food security (FAO, 2018).

Common beans (Phaseolus vulgaris L) are one of the most important food legumes in the world (CIAT, 1989; Soniia et al., 1999). Beans were domesticated in their center of origin, Latin America, where different races exist. It has been one of the primary staple foods in Latin American countries since pre-Columbian time and became one of Africa’s most vital food sources after its introduction (FAO, 2020). The leading producing country of beans in the world is Brazil, with total area coverage of 4-5 million hectares, followed by Mexico with approximately 1,900,000 ha and Central America with 700,000 ha (FAO, 2018). In sub-Saharan Africa, East Africa has the highest bean production of 1,297,000 tons per annum, and the largest producing countries include; Kenya, Uganda, and DRC (Kilimo & UNDP, 2012).

While beans are considered a low-status food, “the meat of the poor” (Soniia et al., 1999), it provides an essential source of protein and is third in the production of calories after maize and cassava (MAFAP, 2013). The poor highly value beans because a big part of the plant can be consumed; the grain can be eaten when fresh or dried. Its leaves are used as vegetables. In some parts of East Africa, beans grain consumption exceeds 50 kgs per person per annum, but this consumption capacity has been declining due to low income and storage losses caused by bruchids (Soniia et al., 1999)

Heavy losses to bean seeds have been due to bean bruchid weevil (Acanthoscelides obtectus) (Ebinu et al., 2016). These pests have also caused poor germination rates when bridging the gap in production based on seasonality and lower market value for bean seeds, thus causing food insecurity (Kembabazi, 2019). Farmers carry out fumigation using an imported chemical pesticide, Aluminum phosphide, to protect beans during storage (Ngegba et al., 2022). However, fumigants have environmental and human health negative impacts making their use increasingly questionable by food practitioners. Industrial pesticides further exacerbate production costs for poor farmers. In this light, various authorities advocate for alternatives (Daglish et al., 2018). In some areas of Tanzania, farmers have employed Integrated Pest Management, which includes traditional insecticide and granary hygiene. However, the method has not been consistent due to scanty investigation of which traditional plants can be used (Mesele et al., 2019). Kilama (2021) used chilli leave powder and fruit powder in Uganda and found that “the highest mortality rate for bruchid in 144 hrs was 81.9 ±2.4, but he left other vital parts of chilli plant roots and bark. Nyamweha et al. (2018) reported moderate activity of cow dung ash with six bruchid weevils out of 20 bruchids after a long period of two weeks. This could be why cow dung ash only limits bruchid weevil movement but does not kill bean weevils immediately. Despite international, regionally, and local intervention efforts, the problem of bruchid weevils in stored beans still exists. The combination of chilli pepper powder and cow dung ash on the bruchid weevils has not been tested. Therefore, this research aims to compare the efficacy of a combination of chili pepper powder and cow dung as alternative pesticides for controlling bean bruchids in stored beans.

1.2 Statement of the Research Problem

The production of beans in Uganda has increased recently, but the storage life has decreased because of bean bruchid weevils (Kembabazi, 2019). Bruchid weevils are suspected of causing a 40% loss of stored bean seeds in Uganda (Nyamweha et al., 2018). Furthermore, personal observation and interaction with farmers show high bean seeds distraction in local stores, schools, and homes by bean bruchid weevils. There are many oral and written stories, newspaper reports, press statements, and unsorted records regarding the development and progress in controlling bean bruchid weevils using ash from wood, rice husks, and legume straws (Kembabazi, 2019). However, limited achievements have been released.

No attempts have been made to assess the efficacy of a combination of cow dung ash and chili-pepper powder from leaves, fruits, roots, and bark in controlling bean bruchid weevils. Therefore, this study will assess the efficacy of a combination of cow dung ash and chili pepper powder from leaves, roots, bark, and fruits.

1.3.0 General Objective

To assess the efficacy of a combination of cow dung ash and chili-pepper powder in controlling bean weevil in stored beans.

1.3.1 Specific Objectives

(i) To determine the difference in the performance of leaves powder, fruit powder, bark powder, and roots of chili-pepper on the infestation of bean weevil on stored beans.

(ii) To determine the performance of the combination of different parts of a chili pepper plant in controlling bruchid weevil in stored beans.

(iii) To determine the effect of cow dung ash on bean weevil control

(iv) To evaluate the combination of cow dung ash and the different parts of chili pepper powder (leave, roots, bark, and fruit) on a population size of bean weevils.

1.4 Research questions

(i) What is the difference in the performance of chilli powder from leaves, roots, and bark fruit in controlling bean bruchid weevils?

(ii) What is the difference in the performance of the combination of chilli pepper parts in controlling bean bruchid weevils?

(iii) What is the effect of using cow dung ash in controlling beans bruchid weevil s?

(iv) What is the effect of the combination of cow dung ash and chilli pepper powder from leaves, roots, bark, and fruits on the population dynamics of bruchid weevils?

1.5 Justification

The need for alternative means of controlling bruchid weevil has been an outcry by many farmers. If not done, the increasing population may lack food, farmers may lack seeds to plant when meeting the next production season, and local shops and schools may waste money buying infested beans. Combinations of the ingredients (chilli pepper and cow dung) that have already been experimented in controlling bruchid weevil is thought to increase the concentration of the components that will result in better efficacy and improvement of the storage of beans. The use of organic substances would substitute for the inorganic pesticide that farmers currently use, and this will save money.