ABSTRACT
Effect of time and density of pigeon pea introduction on productivity of plantain/pigeon pea mixture in South-eastern Nigeria was investigated at the Teaching and Research Farm of Federal University of Technology, Owerri, Nigeria from 2007 to 2010. The study targeted developing an integrated low-input cost effective food production strategy predicated upon plantain/pigeon pea productivity enhancement among the resource poor farmers. Three densities of pigeon pea: 5,000, 10,000 and 20,000 plants ha-1 were intercropped with plantain at planting (0), 3 and 6 months after planting. Sole plantain was the check. The experiment was a 3×3 factorial laid out in a randomized complete block design with 3 replications. Data on soil at the beginning and the end of the experiment were collected and analyzed. Data on the growth and yield parameters of plantain and pigeon pea were also collected and statistically analysed using GenStat software. Analysis of Variance (ANOVA) procedure was used to test treatment effects while significant treatment means were separated using Least Significant Difference (LSD) at 5% level of probability. Results showed that the preexperimental soil was acidic (PH 5.26) and low in nitrogen. At the end of the experiment, pigeon pea introduced 3 months after plantain planting raised the soil organic matter by 49.66%. Plantain intercropped with 10,000 plants ha-1 pigeon pea had the highest percentage (90.13) plantain establishment. Main and ratoon plantains in 3 months plantain/pigeon pea intercropping shot earliest (303.10 and 315.20 days) and matured (379.90 and 402.00 days) respectively compared with those at plantain planting (405.80 and 442.60 days) and (496.90 and 535.00 days) or 6 months intercropping (383.70 and 402.30 days) and (457.00 and 504.30) respectively. Pigeon pea density 10,000 plants ha-1 induced the earliest maturity (423.00 days) while 5,000 plants ha-1 the latest (464.00 days). Plantain intercropped with pigeon pea 3 months after plantain planting had the highest bunch yield of main crop (18.49 ton ha-1) and ratoon (13.69 tons ha-1) while those at plantain planting had the lowest main and ratoon yields (7.94 and 5.08 tons ha-1) respectively. Plantain/pigeon pea 10,000 plants ha-1 gave the highest ratoon yield (11.81 tons ha-1) and the density 20,000 plants ha -1 had the lowest ratoon bunch yield (7.10 tons ha-1). The sole plantain (control) had the poorest ratoon yield (2.50 tons ha-1). Pigeon pea introduced 3 months at density 10,000 plants ha-1 had the highest grain yield 2.84 and 2.18 tons ha-1 while those introduced 6 months at density 20,000 plant ha-1 had the lowest 0.65 tons ha-1 and 0.87 tons ha-1 respectively The land equivalent ratio (LER) 3.12 and benefit cost ratio 82.04 revealed that intercropping plantain with 10,000 plants ha-1 pigeon pea 3 months after plantain planting was the best production package for yield and profit optimization for the resource challenged farmers of the Southeastern agroecology of Nigeria.
Key words: Productivity, plantain, pigeon pea density, time of introduction, intercropping.
TABLE OF CONTENTS
Page
Title – – – – – – – – – – – i
Certification – – – – – – – – – – ii
Dedication————————————————————————————————————— iii
Acknowledgement – – – – – – – – – iv————————————————————————- v
Table of contents—————————————————————————————————— vi
List of Tables – – – – – – – – – – xiii
Abstract – – – – – – – – – – xvi
CHAPTER ONE
1.1 Introduction – – – – – – – – – 1
1.2 Statement of problem – – – – – – – – 6
1.3 Justification – – – – – – – – – 7
1.4 Objective of the research – – – – – – – 9
CHAPTER TWO
2.0 LITERATURE REVIEW – – – – – – – – 10
2.1 Origin of Plantain – – – – – – – – 10
2.2 Classification of Plantains – – – – – – – 10
2.3 Highlight of Plantain Distribution – – – – – – 12
2.4. Production Trends of Plantain – – – – – – 13
2.5.0 Environmental Requirement of Plantain – – – – – 14
2.5.1 Effect of Temperature on Plantain – – – – – – 14
2.5.2 Effect of Water on Plantain – – – – – – 19
2.5.3 Effect of Other Climatic Factors – – – – – 21
2.5.4 Soil Requirements of Plantain – – – – – 22
| 2.5.5 Nigerian Soils and Plantain Production – – – – | 23 |
| 2.5.6 Major Diseases of Plantain – – – – – – – – | 24 |
| 2.5.7 Major Insect of Plantain – – – – – – – – | 26 |
| 2.5.8 Weed – – – – – – – – – – – | 26 |
| 2.5.9 Plantain Production Systems – – – – – – – | 27 |
| 2.5.10 High-Input Plantain Production Systems – – – – – | 27 |
| 2.5.11 Traditional Low-Input Production System – – – – – | 29 |
| 2.5.12 Plantains Mixed With Other Crops in Distant Fields – – – | 29 |
| 2.5.13 Home Gardens – – – – – – – – – | 30 |
| 2.5.14 Plantain Intercropping Production System – – – – – | 32 |
| 2.6.0 Pigeon pea Origin and Distribution – – – – – | 35 |
| 2.6.1 Uses of Pigeon pea – – – – – – – – – | 36 |
| 2.6.1.1 Food – – – – – – – – – – – | 37 |
| 2.6.1.2 Feed – – – – – – – – – – – | 37 |
| 2.6.1.3 Raw Material – – – – – – – – – | 38 |
| 2.6.1.4 Wood Utilization – – – – – – – – – | 38 |
| 2.6.1.5 Soil Ameliorant – – – – – – – – – | 38 |
| 2.6.1.6 Traditional Medicine – – – – – – – – | 40 |
| 2.6.1.7 Other Uses – – – – – – – – – – | 40 |
| 2.6.2. Pigeon pea Intercropping System – – – – – – | 40 |
| 2.6.3.0 Leguminous Nitrogen Fixation – – – – – –
CHAPTER THREE |
46 |
| 3.0 Materials and Methods – – – – – – – – | 50 |
| 3.1 Location and Description of the Study Area – – – – | 50 |
| 3.2 Site Preparation – – – – – – – – – | 50 |
| 3.3 Soil Sampling – – – – – – – | 51 |
| 3.4 Soil Sample Analysis – – – – – – – – – | 51 |
| 3.5 Treatments – – – – – – – – – – – – | 52 |
| 3.6 Experimental Design – – – – – – – – – | 52 |
| 3.7 Planting Materials – – – – – – – – – – | 52 |
| 3.8 Field Mapping – – – – – – – – – – | 53 |
| 3.9 Digging of Plantain Holes – – – – – – – – | 53 |
| 3.10 Planting of Suckers – – – – – – – – – | 53 |
| 3.11 Planting of Pigeon peas – – – – – – – – – | 54 |
| 3.12 Intercrop Arrangement – – – – – – – – | 54 |
| 3.13 Weeding – – – – – – – – – – – | 54 |
| 3.14 Pruning – – – – – – – – – – – – | 54 |
| 3.15 Propping – – – – – – – – – – – – | 55 |
| 3.16 Manure Application – – – – – – – – – – | 55 |
| 3.17 Pest Control – – – – – – – – – – – | 55 |
| 3.18.0 Data Collection – – – – – – – – – – | 55 |
| 3.18.1.0 Plantain Agronomic Data – – – – – – | 55 |
| 3.18.1.1 Days of 50% leaf emergence – – – – – – | 56 |
| 3.18.1.2 Plantain Establishment – – – – – – – | 56 |
| 3.18.1.3 Mat Survival After Harvest – – – – – – – | 56 |
| 3.18.1.4 Leaf Production – – – – – – – – – – | 56 |
| 3.18.1.5 Leaf Area – – – – – – – – – – | 57 |
| 3.18.1.6 Total Leaf Area (TLA) – – – – – – – – – | 57 |
| 3.18.1.7 Leaf Area Index (LAI) – – – – – – – – | 58 |
| 3.18.1.8 Pseudo-stem Height (cm) – – – – – – – – | 58 |
| 3.18.1.9 Number of Functional Leaves – – – – – – –
3.18.1.10 Number of Leaves With Black Leaf Spot at 6 Months After Planting, |
58 |
| at Shooting and Harvest – – – – – – – – – – – – – – – – – – – –
3.18.1.11 Pseudo-stem Girth (cm) at 3 and 6 Months After Planting, |
58 |
| at Shooting and Harvest – – – – – – – – – – – – – – – – – | 59 |
| 3.18.1.12 Days of 50% Flowering – – – – – – – – – – – | 59 |
| 3.18.1.13 Months of 50% Harvest – – – – – – – – – | 60 |
| 3.18.1.14 Bunch Yield (tons ha-1) – – – – – – – – | 60 |
| 3.18.1.15 Number of Hands per Bunch – – – – – – – – – | 60 |
| 3.18.1.16 Number of Fingers per Bunch – – – – – – – – – | 60 |
| 3.18.1.17 Number of Marketable Fingers per Bunch – – – – – – | 61 |
| 3.18.1.18 Individual Finger Weight (g), Girth and Length (cm) – – – | 61 |
| 3.18.1.19 Pest Incidence Scoring – – – – – – – – – – | 61 |
| 3.18.1.20 Crop Growth Cycle (Months from planting to harvest) – – – – | 62 |
| 3.18.1.21 Number of Suckers per Mat – – – – – – – – – | 62 |
| 3. 18.1.22 Number of Suckers by Type – – – – – – – – | 62 |
| 3.18.1.23 Growth and Yield Data of Ratoon Crop (plantain) – – – – | 63 |
| 3.18.1.24 Ratoon Crop Pest and Disease Scoring – – – – – – – | 63 |
| 3.18.1.25 Ratoon Crop Cycle – – – – – – – – – – | 63 |
| 3.18.2.0 Data on Pigeon pea Component – – – – – – – – | 63 |
| 3.18.2.1 Days of 50% Seedling Emergence – – – – – – – –
3.18.2.2 Plant Height of Pigeon pea at 3 and 6 Months After Planting and at Pod |
63 |
| Maturity Harvest – – – – – – – – – – | 64 |
| 3.18.2.3 Number of Branches Plant-1 – – – – – – – | 64 |
| 3.18.2.4 Time for 50% Anthesis (Flowering) – – – – – | 64 |
| 3.18.2.5 Stem Girth (cm) – – – – – – – | 64 | |
| 3.18.2.6 Number of Pods per Plant – – – – – – – | 64 | |
| 3.18.2.7 Number of Seeds per Pod – – – – – – – – – | 65 | |
| 3.18.2.8 Pod Length (cm) – – – – – – – – – – | 65 | |
| 3.18.2.9 100-Seed Weight (g) – – – – – – – – – – | 65 | |
| 3.18.2.10 Grain Yield – – – – – – – – – – | 65 | |
| 3.18.2.11 Stem Dry Weight of Plant Crop Harvest – – – – – – | 65 | |
| 3.18.2.12 Leaf Dry Weight of Plant Crop at Harvest – – – – – – | 66 | |
| 3.18.2.13 Weed Sampling – – – – – – – – – – – | 66 | |
| 3.18.2.14 Earthworm Cast – – – – – – – – – – | 67 | |
| 3.18.2.15 Insect Pests of Pigeon pea – – – – – – – – | 67 | |
| 3.18.2.16 Insect Pollinators – – – – – – – – – – | 67 | |
| 3.18.2.17 Bird Nests – – – – – – – – – – – | 67 | |
| 3.18.2.18 Spider Webs – – – – – – – – – – – | 67 | |
| 3.18.2.19 Reptile and Rodent Holes – – – – – – – – | 67 | |
| 3.18.2.20 Nodule Count – – – – – – – – – – | 68 | |
| 3.18.2.21 Leaf Fall – – – – – – – – – – – | 68 | |
| 3.18.2.22 Intercropping Efficiency – – – – – – | – | 68 |
| 3.18.2.23 Relative Crowding Coefficient – – – – – | – | 68 |
| 3.18.2.24 Competition Coefficient – – – – – – | – | 68 |
| 3.18.2.25 Cost/Benefit Analysis – – – – – – | – | 69 |
| 3.18.3.0 Statistical Analysis – – – – – – – – –
CHAPTER FOUR |
69 | |
| Results and Discussion- – – – – – – – – – – – – – – – – – – – – – – – – – – | 70 | |
| 4.0 Results – – – – – – – – – – – – | 70 | |
| 4.1 Plantain Components – – – – – – – | 70 | ||
| 4.1.1 Leaf emergence, establishment and mat survival | – – – | – | 70 |
| 4.1.2 Number of leaves per plant – – – | – – – | – | 71 |
| 4.1.3 Leaf area per plant – – – – | – – – | – | 71 |
| 4.1.4 Leaf area index – – – – – | – – – | – | 74 |
| 4.1.5 Total leaf area – – – – – | – – – | – | 74 |
| 4.1.6 Number of functional leaves per plant – – | – – – | – | 77 |
| 4.1.7 Sigatoka leaf spot disease – – – | – – – | – | 79 |
| 4.1.8 Plant height and girth – – – – | – – – | – | 81 |
| 4.1.9 Number of days to 50% flowering and harvesting | – – – | – | 81 |
| 4.1.10 Number of hands per bunch – – – | – – – | – | 85 |
| 4.1.11 Number of fingers per bunch – – – | – – – | – | 85 |
| 4.1.12 Bunch and finger characteristics – – | – – – | – | 86 |
| 4.1.13 Bunch yield and marketable fingers – – | – – – | – | 87 |
| 4.1.14 Number of suckers (sucker production) – | – – – | – | 91 |
| 4.2 Pigeon pea Components of the Mixture – – – – – – | 93 | ||
| 4.2.1 Seedling emergence – – – – – – – – | 93 | ||
| 4.2.2 Plant height – – – – – – – – – | 94 | ||
| 4.2.3 Stem girth – – – – – – – – – | 96 | ||
| 4.2.4 Number of branches – – – | – | 96 |
| 4.2.5 Shoot fresh and dry weight – – – – – – | – | 99 |
| 4.2.6 Number of days to 50% flowering and yield components – – | – | 101 |
| 4.2.7 Grain yield – – – – – – – – | – | 103 |
| 4.3 Biological life under the various plantain pigeon pea mixture – – – | – | 105 |
| 4.3.1 Effect on weed fresh and dry weight – – – – – | – | 105 |
| 4.3.2 Earthworm cast – – – – – – – – | – | 105 |
| 4.3.3 Insect – – – – – – – – – | – | 107 |
| 4.3.4 Other biological agents – – – – – – – | – | 108 |
| 4.3.5 Leaf fall dry weight – – – – – – – | – | 110 |
| 4.3.6 Nodulation – – – – – – – – | – | 110 |
| 4.4 Soil Nutrient Status – – – – – – – – – – – | 112 | |
| 4.5 Productivity of plantain/ pigeon pea per unit area- – – – – – – – – – – – | 119 | |
| 4.6 Assessment of intercrop advantage – — – – – – – – – – – – – – – – – – –
4.7 Input and variable cost of plantain production at various times and |
119 | |
| densities of pigeon pea introduction- – – – – – – – – – – – – – – – – – | 122 | |
| 4.8 Discussion – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – | 128 | |
| 4.8.1 Plantain first leaf emergence – – – – – – – | 128 | |
| 4.8.2 Plantain establishment – – – – – – – – | 128 | |
| 4.8.3 Total leaf area – – – – – – – – – | 129 | |
| 4.8.4 Plantain Height – – – – – – – – – | 131 | |
| 4.8.5 Stem girth: – – – – – – – – – | 131 | |
| 4.8.6 Sigatoka leaf spot disease and pest incidence – – – – – | 132 | |
4.8.7 Flowering and bunch harvest – – – – 133
4.8.8 Bunch yield and marketable fruits – – – – – – 134
4.8.9 Pigeon pea components of the mixture – – – – – – 135
4.8.10 Height of pigeon pea as affected by its time and density of introduction – – 136
4.8.11 Branching of pigeon pea as affected by time and density of
pigeon pea introduction – – – – – – – 137
4.8.12 Effect of time and density of pigeon pea introduction on yield
attributes and grain yield of pigeon pea – – – – – 138
4.8.13 Biological life under various plantain/pigeon pea mixtures – – – 140
4.8.14 Earthworm activities – – – – – – – – 140
4.8.15 Insects – – – – – – – – – – 141
4.8.16 Productivity of plantain/pigeon pea intercrop – – – – – 146
4.8.17 Assessment by land equivalent ratio – – – – – – 146
4.8.18 Assessment of intercropping competition by relative crowding
coefficient (RCC) and competition coefficient (C) – – – – 147
4.8.19 Monetary assessment of plantain/pigeon pea intercropping system – – 148
CHAPTER FIVE
5.0 Summary, Conclusion and Recommendation – – – – – – – – – – – – – – 149
5.1 Summary – – – – – – – – – – – – – 149
| 5.2 Conclusion – – – – – – – – – – – | 150 | |
| 5.3 Recommendation – – – – – – – – – – – | 151 | |
| 5.4 Contribution to Knowledge – – – – – – | – | 152 |
| References – – – – – – – – – – – – – | 153 | |
| Appendix 1 – – – – – – – – | – | 186 |
| Appendix 2 – – – – – – – – | – | 187 |
CHAPTER ONE
1.1 INTRODUCTION
Plantain, Musa AAB group belongs to the family of Musaceae of the genus-Musa. The species –Musa AAB, formerly Musa paradisiaka (Robinson, 1996) has been identified as an important staple food in the humid tropics of Africa, Asia and America (Ogazi, 1996). Plantain also constitutes an important food crop of majority of the inhabitants of Western and Central African sub-regions (Ekanayake etal.,1995) including the high rainfall areas of Eastern Nigeria (Unama et al.,1985). In these areas, plantain provides more than 25% of the carbohydrate and 10% of the calorie intake for approximate 70 million people, making the crop one of the most important sources of food energy in the region (Devos et al., 1980; Swennen, 1990; IITA, 1992 Nweke et al., 1995;).
Until recently, plantain was considered a food of little nutritional merit, particularly due to low protein content of 3.0g/100g and 3.5g/100g dry samples for unripe and ripe pulp respectively (Ketiku, 1973). This low protein content was then a suspect of protein energy malnutrition leading to kwashiorkor in children (Chandler, 1995). However, the high energy value of 35k.cal/100g of plantain is highly commendable (Ogazi, 1996) and readily processed into different foods such as fufu, porridge and chips (Ogazi, 1996 and Chandler, 1995). Roasted plantain along roadsides in Owerri, Enugu, Port-harcourt and other Nigerian cities is a popular snack for travellers and urban dwellers.
In some parts of East and West Africa, plantain is as important as grain and root crops, providing the cheapest staple per kg per hectare and per 100 calories of all the food crops such as cocoyam (Colocasia esculentus), yam (Discorea spp), cassava (Manihot esculenta), sweet potato (Ipomoea batatas), rice (Oryza sativa) and maize (Zea mays) grown in the ecozone (Stover and Simmonds, 1987). Plantain has a lot of potentials and can be processed into composite flour used in the production of bread, biscuit, cake and other confectioneries (Ogazi, 1996). Plantain is a versatile raw material in the production of industrial alcohol, juice and powder (Adams and Flynn, 1982; Stover and Simmonds, 1987 and Thompson, 1995). Accordingly, plantains contribute positively to agro-industrial development and import substitution strategy often adopted by most developing countries (Njoku, 1990). The peels are also utilized in the production of bio-gas methane, animal feed component and tenderizers (Ogazi, 1996). The annual production of 2.4 million metric tons of plantain in Nigeria (Ogazi, 1996) is grossly inadequate to meet the increasing demand of the produce for domestic and industrial purposes.
Plantain was introduced from South-east Asia and adopted into the farming systems of the humid forest zone of Africa between latitudes 4º30’N to 8º10’N (Obiefuna, 1984) which provides hot humid environment for good yield. In the humid forest zone of Africa, plantain has acquired considerable nutritional and economic significance (Swennen and Vuylsteke, 1991; Ortiz and Vuylsteke, 1994).
The major plantain growing areas of the world are located between equator and latitudes 20ºN and 20ºS (Robinson, 1996). Climatic conditions in these areas are mainly tropical with comparatively small temperature fluctuations from day to night and wet season to dry season.
According to Stover and Simmonds (1987), optimum temperature for foliar growth is 2628ºC and slightly higher at 29-30ºC for fruit growth. Growth begins at 18ºC, reaches optimum 27ºC, then declines and comes to a stop at 38ºC (Samson, 1989). Turner and Lahav (1983) observed highest dry weight at 25ºC/18ºC and greatest leaf area at 33ºC/26ºC with banana (Musa sapientum) in growth chamber.
Plantain has a relatively very high water requirement and it is very negatively sensitive to dry soil condition (Ekanayake et al., 1995). This generally limits its traditional areas of cultivation to mostly southern Nigeria where there is good rainfall (about 1000mm-2500mm annually) and warm weather of about 20-35ºC (Swennen, 1990; Robinson, 1996).
Thus plantain features prominently in the farming systems of the rainforest belt of Nigeria especially South- eastern Nigeria (Unama et al., 1985) with high concentration in Rivers, Cross River, Akwa Ibom, Imo, Anambra, Delta, Edo, Ogun, Osun, Ondo and Oyo States with favourable ecological conditions for the cultivation of the crop (FMAWRRD, 1989; Adelaja, 1997; Ibia and Udo, 2009).
Rich alluvial soils and medium to heavy textured soils with pH range of 5.5-7.5 are more suitable for the optimum performance of plantains (Ibia and Udo, 2009). Ndubizu (1985), observed that areas with annual water deficit between 400-300 are marginal for plantain production while areas with 300-250mm and 250-150mm are suitable and ideal respectively.
Plantain is therefore very sensitive to dry soil conditions (Swennen, 1990; Ekanayake et al., 1995; Robinson, 1996). The crop is cultivated on diverse soils ranging from highly fertile andisols to low fertile old ferrallitic soils in West Africa (Delvaux, 1995; Delvaux et al., 2000).
Three plantain production systems are dominant: Distant field-under shifting cultivation, homestead- in rural/urban backyards; and monoculture (Akyeampong, 1999) are commonly identifiable in the humid tropics of West Africa.
In Nigeria like other places in the humid agroecology, plantains are mostly cultivated in compound or back yard gardens where they benefit from copious addition of organic matter and household refuse which maintain soil fertility and sustain plantain productivity (Wilson et al., 1987; Swennen, 1990; IITA, 1995; Nweke et al., 1995; Robinson, 1996; Akyeampong, 1999).
In the search for suitable forestland to cultivate the crop, farmers have moved quite far away from their homestead and villages. Transporting the heavy bunches from distant farms to the village or road sides is arduous. Also, away from the watchful eyes of the owner, theft of bunches in the distant fields especially during the lean season, when other food stuffs are scarce but plantain is at peak production, is very common. For these reasons, production in gardens around the homestead is becoming increasingly important as a source of plantain production.
Thus, in home gardens plantain is planted as part of the multistrata system comprising fruit and other trees of economic value at the upper stratum and other food crops below the plantains. Despite competition from the intercrops, plantain yields from home gardens are high as the crop benefits from the application of large doses of household refuse which is high in organic matter (Yao, 1988) and mineral rich kitchen ashes. The yield of the wellmanured and adequately watered plantains in this system is sustainable despite the presence of the usual Musa pests (Cosmopolites sordidus) and Sigatoka leaf spot disease (Akyeampong, 1999).
Plantain production is expanding rapidly in the West African sub region to meet the continuous high demand arising from rapid urbanization and rapid increase in population (Obiefuna, 1986). Interest in the cultivation of the crop by Nigerian farmers for higher economic benefit has been kindled in the recent past. Continuous expansion of plantain production in backyard gardens is fast becoming very slow due to sharp increase in population and consequent limited space available. Furthermore, agricultural lands available for farming families continue to diminish because of high population pressure and the attendant land fragmentation characteristic of the plantain growing regions (Obiefuna et al.,
1982, Obiefuna and Ndubizu, 1982).
Plantain yields under field conditions are generally low (5-15tons ha-1) and seasonal (IITA, 1989) and declines rapidly after 1-2 harvests, in contrast to the backyard production system where the soil fertility is very high (Braide and Wilson, 1980). Reasons for rapid yield decline in the field grown crops have been attributed to high susceptibility to nematodes and the plantain corm borer weevil (Cosmopolites sordidus), weed competition, high mat phenomenon and the devastating black Sigatoka disease (Braide and Wilson, 1980; Babatola, 1985, Swennen et al., 1988; Ortiz and Vuylsteke, 1994).
Besides the detrimental effect of these factors, one of the major obstacles to increasing plantain production in the humid tropical environment is poor soil fertility status. Low level organic matter and soil fertility related constraints are very critical in the production of plantain (Obiefuna, 1986; Robinson, 1996). In a swift move to remedy the situation, the use of sawdust mulch in conjunction with inorganic fertilizer was recommended (Obiefuna, 1986).
More similar reports of rapid decline in fertility and productivity have been made for several soils supporting plantain and other food crops in south eastern Nigeria (Periaswamy et al., 1983; Eshett, 1987). The low fertility and productivity of humid tropical soils arising from their inherently low organic matter content make them unsuitable for continuous cultivation (SMSS, 1986; Kang and Akinnifesi, 1994; Odetayo et al., 2013). Under this unsustainable fertility condition, yield decline in field grown plantain becomes even more complicated and acute in the low input traditional intercropping systems which all plantains are usually subjected with cash and other food crops in the humid tropics (Braid and Wilson 1980;
Unama et al., 1985 and Obiefuna, 1986).
Intercropping of plantain has been reported in Andes regions of South America (Stover and
Simonds, 1987), the West Indies (Rao and Edmunds, 1984) and the Philipines (Alviar and Cuevas, 1976).
In the rain forests of West Africa, Devos and Wilson (1979), Ikeorgu et al., (1989) and Oko et al., (2000) noted that intercropping is usually practised by low income families to maximize the use of land and to provide extra food and cash. Obiefuna (1984) also reported that intercropping plantain with other food crops has been a practice by the resource poor famers. In the humid tropics especially in the Southeastern Nigeria, plantains are frequently intercropped with food crops, maize and cassava (Devos and Wilson, 1979), coco-yam and cowpeas (Kari-kari, 1980; Shiyam et.al. 2004; Rao and Edmunds, 1984) and vegetable egusi melon (Ikeorgu et al., 1989).
Wilson (1987) earlier observed a higher and more sustainable yield of plantain (30-50 tons/ha) from backyard gardens than plantations in second and third ratoon crops. Plantain cultivation is usually profitable for one to two years after which soil fertility declines, resulting in annual plantain yields as low as 4-8 t ha-1 (Nweke et al., 1995; Shiyam et al., 2004). Robinson (1995) therefore concluded that rapid depletion of soil fertility and organic matter, nematode build up, erosion, soil compaction, low pH and loss of spatial arrangement are the major causes of yield reduction in plantain after the first crop cycle in the plantation.
1.2 STATEMENT OF PROBLEM
Seasonal availability and low fruit yield are major problems associated with plantain production in the rain forest agro-ecology of southeastern Nigeria. Seasonal availability is caused by poor ratoon growth and low fruit yield is caused mainly by poor soil fertility. The consequences of these are plantain food insecurity and plantain growers/farmers impoverishment. This research therefore was aimed at development of plantain/pigeon pea intercropping system for enhancement of plantain ratoon growth and soil fertility for fruit yield improvement. Pigeon pea (Cajanus cajan (L) Millsp.) according to Danso (1992) improves soil fertility through biological nitrogen fixation, solubilizes phosphorous from ion bound form (Ae et al, 1990) and contributes to organic matter accumulation through leaf-fall at harvest (Sheldrake Narayanan, 1979).
1.3 JUSTIFICATION
Producing plantain in mixture or intercropping with legume Pigeon pea in the ultisols of Southeastern Nigeria has not received much research attention. Moreover, less research attention has also been given to Pigeon pea in Nigeria, mainly due to lack of information on its agronomy, socio-economic and nutritional importance (Tom and Asiegbu, 2002).
Pigeon pea (Cajanus cajan (L) Millsp.) belongs to the family of leguminoceae in the genus cajanus, subtribe-cajaninae and the tribe Phaseolae (Vander Maesen, 1981). It is one of the leguminous crops which has been cultivated for human consumption and for feeding of livestock in many parts of the world. Pigeon pea ranks fifth in the world, but first in India, in importance among edible legumes (Morton, 1976); Whiteman et al., 1985).
In Southeastern Nigeria, pigeon pea is cooked as whole seed and porridge with steamed dry cocoyam chips in a form popularly called in Igbo language “achicha” particularly by the Igbos from Enugu and Anambra States. The dietary importance of the pigeon pea has been widely recognized. For example, in high quality protein averaging 7% in un-ripe seeds and varying from 18-32% in mature seeds (Morton et al., 1982). International Crops Research Institute for the Semi- Arid Tropics (ICRISAT, 1984) reported that the protein content of
Pigeon pea grain is about 21-24%, with the range of amino acid needed for good human nutrition. The husk of the pod is used as cattle feed and the green foliage as green manure or fodder, while the woody stems are use for making baskets, wicker fences and thatch (Bolaria, 1982; Lateef and Reed, 1990).
In Africa, largely long-duration (7-11months), tall and indeterminate cultivars of pigeon pea with large white seeds (12-20g/100 seed mass) are grown as an intercrop with cereals like maize (Zea mays), sorghum (Sorghum bicolor), pearl millet (Pennisetum sp), and a variety of other crops such as cassava (Manihot spp), cotton (Gossypium sp), cowpea (Vigna unguiculata L), and beans (Phaseolus lunatus) (Singh, 1990). In the derived savannah of Nsukka, Kogi and Benue the long duration Pigeon pea is a common intercrop with cassava and cocoyam in the traditional farming systems of the people. Information on planned research and findings from Pigeon pea intercrop with plaintain in the humid tropics is scanty. This situation needs to be addressed in order to make advances in plantain-pigeon pea based cropping system.
Soil physico–chemical properties need urgent investigation in both intercrop and sole plantain cropping systems to ascertain soil amelioration potential of pigeon pea at various densities and times of introduction.
The on-going Organic Agriculture Movement discourages continuous use of synthetic agrochemical inputs that are harmful to soil, plant, animal, human and planet. With the already low inputs of fertilizers in African farming system, Danso (1992), suggested harnessing biological nitrogen fixation to its fullest extent in the cropping systems of the resource-poor farmers.
Pigeon pea has the potential of improving soil fertility in the cropping system by recycling water at soil depth during drought (Sheldrake and Narayanan, 1979). It also solubilizes phosphorus from ion bound form (Ae et al., 1990). The crop further contributes to organic matter accumulation through leaf-fall at harvest (Sheldrake and Narayanan, 1979).
In view of these potentials, it is important that efforts should be made to continually improve and sustain the productivity of plantain and pigeon pea through appropriate plant population and time of pigeon pea introduction in plantain/Pigeon pea intercropping system.
Finally, this study will further enrich the pool of already existing research information on plantain cultivation under the traditional smallholder mixed production systems that will remain the major producer of food in Nigeria in the foreseeable future.
1.4 OBJECTIVES OF THE RESEARCH
This research has as its objective the development of an integrated low-input, cost effective food production strategy predicated upon plantain-pigeon pea productivity enhancement for food security and poverty alleviation among the resource-poor farmers. The specific objectives of the experiment were to:
- determine compatibility of pigeon pea and plantain in mixture at different plant densities and times of introduction.
- ascertain growth pattern of plantain and pigeon pea at various pigeon pea densities and times of introduction.
- determine the yield and yield components of plantain/pigeon pea mixture.
- determine the physico-chemical properties of the soil at the beginning and end of the study.
- determine the profitability of plantain/pigeon pea mixture.
