Abstract

Three cassava varieties, the local red, local white, and the improved variety 8034 were evaluated in a completely randomized design with three replications at the Faculty of Agriculture and Veterinary Medicine farmland from December 2014 to March 2015. The primary objective of this project is to study the performance of three cassava varieties in Buea.

The growth habits such as plant height, petiole length internode length, and a number of main branches were evaluated. Incidence of CMD was determined and severity was scored over these months.  The results show significant differences (P<0.05) between the three varieties for most growth responses, incidence, and severity of CMD.

The local red variety presented the highest value (90.7) in terms of plant height compared to the local white variety (70.6) and the improved 8034 IRAD variety (57.9). The petiole length ranged from the least, 23.5 in 8034 to 34.3 in the local red variety.

There was no significant difference between the three varieties in terms of internode length and a number of main branches but the least significant difference exists between the local red variety and the local white variety in terms of main branches.8034 had the highest incidence (67.3 %) but the least severity score(1.5), followed by the local red with the highest severity score (2.2) and incidence of( 62 %) for CMD. Incidence and severity of CMD were attributed to genetic differences in variety, plant age, and the growing season.

CHAPTER ONE

INTRODUCTION

1.1 General background

Cassava is currently the most important carbohydrate food source after rice, sugarcane, and maize for over a 500million people in the developing countries in the tropics and subtropics (FAO, 1999). It is a woody perennial of the Euphorbiaceae family, with over 5000 distinct varieties (Alves, 2002).

Cassava is native to the South American country of Brazil, where it was first domesticated and later on introduced to the African region by the Portuguese traders in the 16th century (Jones, 1959). The major cassava producers in the world are; Nigeria, Brazil, Thailand, Indonesia, Mozambique, Uganda, Madagascar, and a host of other countries.

In Cameroon, cassava ranks first among roots and tuber crops in terms of total production and consumption, and yearly production is estimated at 2.3million tons, with the center, east, and south regions being the most productive areas (PNDRT, 2005). Cassava bi-products being “garri” and “water fufu” are the first source of starchy food in the whole of southern Cameroon (PNDRT, 2003; ECAM III, 2007)

The total acreage of land dedicated for cassava cultivation in Cameroon is 9200ha (FAO, 1991) with small plots being less than 2ha, mid-plots between 2-4ha, and large plots above 4ha (Tsounkeu, 2010). Statistics have shown that the highest cultivation of cassava is done by 90 percent of women in this region (Tolly, 2013).

Smallholder farmers in Cameroon grow various cassava cultivars, and there are marked producer and consumer preferences as to the type of variety grown, and these determine the uptake of new varieties (Zundel et al.; 2010).

Cassava is rich in starch and is consumed in several forms; mashed, boiled, or fried. It is also processed industrially to form pellets for animal feed, ethanol, and high-quality cassava flour (Sarr et al., 2013). Cassava as well creates employment for many involved in its cultivation.

1.2 Problem statement                     

Several varieties of cassava are cultivated in this region, especially the local type but they are largely affected by several pests and diseases. This constraint tends to reduce the yield of cassava drastically.

There has been very little effort made to evaluate existing varieties and new introductions for their performance and adaptability under local conditions. Consequently, there is a need to conduct a study on cassava in order to identify which of the varieties cultivated in the Buea municipality is most resistant to pests and diseases.

1.3 Justification

Cassava’s high starch content in the form of carbohydrates, its adaptability and growth performance in various agro-ecological zones, its resistance to drought, and its ability to grow under a wide range of conditions make it a very important economic crop to farmers in Cameroon.

Cereals have remained a major energy source with maize being most common, contributing from 60-80 percent starch (Damisa et al., 2007). The production of cereals (maize for instance) has declined with yields being less than a ton per hectare (Muza et al., 1998) due to the increase in the cost of inputs and fertilizers beyond the reach of the farmers (Chitiyo and Kasele, 2004). This problem is also compounded by the fact that most of these staples are imported at high foreign exchange costs.

The most plausible strategy in solving this problem is therefore an increase in crop diversification and low input crops such as Cassava, which tolerates stressful conditions (Chitiyo, 2004).

This has led to the development of high-yielding cassava varieties which are resistant to pests and diseases in Cameroon (PNDRT, 2010). Since cassava can alternately replace rice and maize as energy sources, it is therefore of great importance to evaluate these three varieties so as to determine the variety best suited for recommendation to the local farmers in this region. This is so as to boost food security amid the ever-increasing population and reduce cost since cassava products are components of basic food intake for 7 to 8 million people in Cameroon (FAO, 2010).

1.4 Hypothesis

1.4.1 Null hypothesis (Ho)

There is no significant difference in the growth habits of the three cassava varieties.

1.4.2 Alternate hypothesis (Ha)

There is a significant difference in the growth habits of the three cassava varieties.

1.5 Objectives

1.5.1 General objective

The main objective of this project is to study the performance of three cassava varieties, the local red variety, the local white variety, and the improved 8034 variety in Buea.

1.5.2 Specific objectives;

The specific objectives for this study are;

1. Measuring and accessing the growth parameters of two local cassava varieties and comparing them with the improved variety (8034).
2. Identifying the key factors in varietal variation.
3. Test for the incidence and prevalence of the cassava mosaic disease.