Abstract

This project was conducted in teaching, research, and production farm of the Faculty Of Agriculture And Veterinary Medicine situated behind U-block in the University of Buea, to study the effect of plant spacing on the growth and yield of common beans under 4 levels of plant spacing via 60cm x 20cm, 45cm x 15cm, 30cm x 10cm and 23cm x 5 cm.

Different spacing affected various growth and yield parameters such as plant height, the number of leaves, stem diameter, and the number of pods. Closely spaced plants attained maximum height 4weeks after sowing but recorded minimum numbers of leaves, stem diameter, and a number of pods.

Narrow spacing influenced yield attribute positively, a higher number of pods compared to closely spaced plant which accommodated more number of plants per plot that might contribute toward higher production; 60cm x 20cm was found to be optimum since it achieved a higher number of pods. The treatments had significant differences (P<0.05) on stem diameter and number of pods relative to the control

CHAPTER ONE

INTRODUCTION

3.1 The common bean crop

Of all annual leguminous food harvested for dry seeds, the ordinary beans are by far the most important. It originated in Central and South America and it is an important dietary legume for more than 300 million people especially in developing countries with a total production exceeding 23 million metri tones, 7 million of which are produced in Latin America and Africa (Broughton et al, 2003). Dry bean seeds represent an affordable and inexpensive source of protein especially in developing countries where more than 60% of dietary protein comes from beans. The crop has often been referred to as poor man meat since the main source of protein for low-income socio-economic strata.

In Cameroon, the Western highlands are the biggest common beans producing zone in the country with more than 90% of the national production. Common bean production is constrained by several fields and post-harvest pest and disease which limits the yielding potentials or cause significant reduction in crop yield.

Some of the prevailing diseases include; angular leaf spot disease bacterial wilt, bean common mosaic virus, common rust. Common insect pests and vectors include Mexican bean beetle, thrips whiteflies, potatoes leafhopper, bean hopper.

1.2 Classification

Kingdom; Plantae

Phylum: Diacotylondae

Order: fables

Family: Fabaceae

Subfamily: Faboideae

Genus: Phaseolus

Species: Phaseolus vulgaris

1.3 Botany

Common bean is an annual, self-pollinated crop, mostly grown in tropical and sub-tropical areas of the world. The leaves are the compound, trifoliate leaves composed of three leaflets, a petiole, and rachis.

The petiole and rachis grooved, the leaflets are glabrous or subglabrous. The flowers are borne in the auxiliary and terminal racemes which may be one or many flowers. The flowers of common beans are zygomorphic having a bi petalled keel, two lateral wing pelat, and a large standard petal.

The colour of the flower may be white, pink, or purple and is genetically independent of the seed colour but there is an association of particular seed colour with flower colors. The flower contains 10 stamens and a multi ovule ovary which is predominantly self-fertilized.

Once fertilized, it develops into a pod that could be straight or slightly curved. The seed born in the pod may be rounded, elliptical, flattened or rounded elongated in shape with an assortment pattern that is used to differentiate the cultivars.

Root growth is imitated through division in the epical root meristem of the radicle of the embryo and subsequent enlargement of these cells. Like other members of the sub-family Faboideae P. vulgaris has root nodules distributed on lateral roots of the upper and middle parts of the root system. The nodules are polyhedral in shape and approximately 2 to 5mm in diameter

1.4 Types and common varieties of common bean

Common bean can be divided into 2 main groups; those that can be eaten fresh pods or snap bean and those that are eaten shelled and dried. They are many varieties of fresh beans which include; azuki, lima, scarlet runner, soya bean, chickpea, cranaberry. Dry beans are left to mature and dry on the vine.

Common beans are generally grouped into 3 common types: bush, semi climbers, and climbers. Bush bean grows to a certain size, they blossom, and fruits then stop growing. They grow to about 38-60cm and are edible within 60 days. The semi-climbers and climbers produce climbing vines after about 3 weeks thus they require support as they grow.

Some common varieties in Cameroon include:

Bush types;Ecapan 021, Ecab 0019, Feb 193, CIM 9331-1, KNV 122, ECAB 0241

Semi-climbers; PH201, ECAB 0056, Menseki, BF-10, TY3396-12, G20854, MCM2001

Climber; PB, Mex142, MAC24, MAC18, SEPE, ROBA-1, KJ4-3 (Ngueguim et  al,. 2011)

1.5 Ecology

1.5.1 Climatic requirement

The dry bean is an annual crop that thrives in a warm climate. It grows optimally at a temperature of 18-24c, the maximum temperature during flowering should not exceed 30c. High temperature during the flowering stage leads to abscission of flowering and a low pod set, resulting in low yield. Day temperatures below 20c will delay maturity and cause empty mature pods to develop

For cultivation, under rainfed conditions, the crop requires a minimum of 400 to 500mm of rain during the growing season but an annual total of 600 to 650mm is considered ideal.

1.5.2 Soil requirement

Beans have to be planted in warm soils (temperature less than 13c). They grow well in soils with a depth of at least 90cm, which have no deficiency and are well-drained. Sandy loam, sandy clay loam, or clay loam with a clay content of between 15 and 35% is suitable. With sandy soils, problems of low fertility or nematodes damage may occur.

Beans prefer an optimum soil pH of 5 to 6 and are very sensitive to acidic soils. They will not also grow well in soils that are compact, too alkaline, or poorly drained.

1.6 Problem Statement

Common bean has a wide range of planting distance depending on the growth type, but most farmers have tended to use distances lower than the recommended ones with the notion that if the plant population is increased it will lead to a corresponding increase in the yield.

These have led to the misuse of planting seed since over 70% of beans farmers in Buea believe in this. Hence the main reason to undertake this study is to know the best planting distance that can be used to obtain optimum yield.

1.8 Justification or rationale of the study

Common beans are the main source of dietary protein in Cameroon especially with the increasing cost of other dietary products like meat, fish, milk, etc.

It also serves as a rotation crop especially with cereals, reducing soil pathogens and supplying nitrogen to the soil (Beebe, 1997).

The ability of this legume to fix nitrogen and improve soil health can enhance overall farm productivity and smallholder income, as they diversify farming systems making them more nutrient efficient resilient, and sustainable.

Leaves are occasionally used as a vegetable and the straw is used for fodder.

1.8 Hypothesis

1.8.1 Null hypothesis (H0)

An increase in plant density has no effect on the growth and yield of common beans

1.8.2 Alternative hypothesis (HA)

An increase in plant density has an effect on the growth and yield of common beans

1.10 Objective

1.9.1 Main Objective

To determine the effect of different plant densities on the yield and growth of common bean.

1.9.2 Specific objective

1. To the effect of planting distance on the yield of common bean.
2. To determine the varietal effect on growth and yield of bean