CHAPTER ONE

INTRODUCTION

I.1. Background

Maize (Zea mays L) commonly known as corn in the United States and Canada, is the third most important cereal grain worldwide after wheat and rice (Golob et al., 2004). It is referred to as the cereal of the future for its nutritional value and utilization of its products and by-products (Lee, 1999). The demand for maize has been estimated to increase by 50%, from 558 million metric tons in 1995 to over 800 million metric tons in 2020 (Martinez et al., 2011). This enormous increase was due to diverse uses of corn, from food and animal feed to ethanol production (FAO, 2006). It is a basic staple food grain for large parts of world including Africa, Latin America, and Asia (Yaouba et al., 2012).

In tropical and subtropical countries, a large proportion of the grain (such as maize) is harvested and stored under hot and humid conditions, and most farmers lack proper knowledge, equipment and methods of drying grains (Weinberg et al., 2008). Subsequently, the maize is stored while still relatively moist and warm; both warmth and high moisture contents can result in rapid deterioration of the grains and promote the growth of microorganisms (fungi and bacteria) and

insects in the grains (Ekechukwua and Norton, 1999). Maize, like other stored products is hygroscopic in nature and tends to absorb or release moisture. Even if properly dried after harvest, exposure to moist and humid conditions during storage will cause the kernel to absorb water from the surroundings (Devereau et al., 2002), leading to increase maize moisture contents, which result in enhanced deterioration. To maintain high quality maize during storage, maize should been protected from weather (including relative humidity and temperature), growth of microorganisms, and insects (Oyekale et al., 2012). According to Campbell et al., (2014), the current estimates of the cost of grain loss due to insect and microorganism damage of grain stored in developing countries each year ranged from $500 million to $1 billion (Tuite and Foster, 1979) Also reported that insects in grain enhance mould development because they increase moisture content and temperature, and open areas of the grain for attack.

Fungal growth in maize is facilitated by hot and humid conditions (Egal et al., 2005). It has been

reported by several researchers that fungal infestation in maize results in colour change, decreases in nutritional values, and reduction of overall quality and quantity of the maize. Major fungi associated with grain storage, including maize, are Aspergillus flavus, Fusarium sp., and others. Fungal growth in maize presents a major risk for humans and animals, through production of mycotoxins (especially aflatoxins). The objective of this article was to review the published literature and discuss the main factors that lead to deterioration of maize in tropical countries, and to suggest ways of preventing the identified causes.

I.2. Problem statement

There are many factors(Abiotic and Biotic) that affects maize storage in Bambui. Many pest (weevils, fungi, insects, magots ect) can be involved in stored maize infestation, resulting in grain damage. However, there’s a poor information on maize storage in Bambui.   is not achieve despite efforts made by peasants. This may be due to the time of cultivation, harvesting time and method of storage. Poor maize storage can lead to low availability and famine. Many pest can be involved in stored maize infestation, resulting in grain damage. However, there is poor information on this situation in Bambui.

I.3. Objectives

I.3.1. Main objective

To bring out the impact of maize infestation during traditional storage in Bambui, and evaluate the efficacy of airtight storage in preserving maize.

I.3.2. Specific objectives

There are many specific objectives:

• To identify the constraints faced by maize producers during storage in Bambui.
• To evaluate maize losses at harvest in Bambui
• To assess the effect of airtight storage on maize protection against Sitophilus zeamais.

I.4. Research questions

• What are the constraints faced by maize producers during storage in Bambui?
• What level of losses is achieve by maizes producers in Bambui at harvest?
• How effective is the prevention of maize against Sitophilu zeamais in airtight storage?