CHAPTER ONE

INTRODUCTION

1.1. BACKGROUND

Maize (Zea mays L) is one of the major cereal crops grown in the humid tropics and Sub-Saharan Africa. It is a versatile crop and ranks third following wheat and rice in world production (FAO, 2002), Maize is an annual crop of the family Poaceae, commonly known as the grass family and is a key source of food and livelihood for millions of people in many countries of the world (Adeniyan,2014).

Maize is an annual plant, surviving for only one growing season prior to harvest and can reach 2–3 m (7–10 ft) in height. The term maize is derived from the Spanish form of the Arawak Native American term for the plant. However, it is popularly called corn in the United States, Canada, New Zealand and Australia and is believed to originate from Mexico and Central America before spreading to other parts of the world.

According to Pepó and Sárvári (2013), maize is a plant with individual productivity; therefore plant density determines yield significantly. Optimal plant density can be affected by the genetic properties, time of planting, extent of water and nutrient supply, weeds, pest, diseases, climatic and soil conditions.

After wheat and rice, maize is the third most cultivated crop globally (David and Adams 1985). Different varieties of maize which include; flour corn, popcorn, dent corn, flint corn, sweet corn, Amylomaize and striped maize have been identified and cultivated by farmers in different parts of the world. Maize is mainly cultivated for its grains to be used as food for man and livestock.

Maize can be consumed in variety of ways; eaten when still fresh on the cob after boiling or roasting, mill into flour (maize starch) which is further baked into maize-related products. Maize starch has been utilized in various ways, including the production of noodles. Edible oil which is obtained from maize grain has a low level of saturated fatty acids compared to other protein sources especially animal sources. Khawar et al (2007) reported high-fructose content of corn syrup and sweetener, which can be added to food to preserve its moisture content.

In Cameroon, maize is produced throughout the country under diverse environments including both dry and rain fed conditions. The productivity of maize is hampered by a good number of constrains. Amongst the major constraints limiting maize productivity are abiotic and biotic stresses (Vivek et al., 2010). These constraints vary among growing areas and between cropping seasons. For example, disease epidemics and insect pest out breaks frequently occur as a result of the warm climate and/or high rainfall common to many maize production zones in Sub Saharan Africa (Vivek et al., 2010). Several diseases are endemic to most Sub Saharan Africa maize production areas and these include maize streak virus (MSV), grey leaf spot (GLS), stem rot, leaf blight,  rust, sugarcane mosaic, northern leaf blight (NLB), ear rots, head smuts and Phaeosphaeria leaf spot (PLS). These diseases are often difficult to control since their occurrence year after year is less predictable because of their high dependence on weather. The pest problem associated to maize production include; corn borer, fall army worm, weevils (at storage). As a result, in favourable seasons with high rainfall, pest and diseases also become more prevalent and damaging. The majority of small-scale farmers, in most cases, do not control the diseases due to limited access to pesticides. Therefore, the development of maize cultivars with enhanced levels of disease resistance and high abiotic stress tolerance will be sustainable and effective for increased maize yields, especially in the smallholder farming sector. Abiotic constrains that limit maize production include; drought, flooding, extreme temperatures, salinity, nutrient deficiency, water logging.

1.2. PROBLEM STATEMENT

As human population continuous to increase, there is need to produce more food in other to feed the ever growing population. As food plays a crucial role in human biological functioning, then the production of food becomes a necessity. Increase food production has been a problem in tropical lands, with cases of limited land. As days go by, more and more agricultural land is lost to urbanization which encompasses construction of industries, roads, bridges, houses and other infrastructures and desertification. To combat these problems, the use of the limited available land to produce more food is empirical.

1.3. OBJECTIVES

1.3.1. MAIN OBJECTIVES

This work is aimed at investigating the optimum planting density at which higher yield can be recorded given the limited land available.

1.3.2. SPECIFIC OBJECTIVES

1. To evaluate the effect of planting density on the yield of maize.
2. To determine the optimum planting density for increased maize productivity.

1.4. HYPOTHESIS

Ho; there is no significant difference in the yield and productivity of maize cultivated at different plant densities.

Ha; there is a significant difference in the yield and productivity of maize cultivated at different plant densities