Thesis Abstract

Abstract
The vegetative propagation of African black pepper (Piper guineense L.) is a crucial aspect of its cultivation due to the high demand for this plant in various industries. This study aimed to evaluate the effects of cutting type and different rooting media on the vegetative propagation of African black pepper. Three cutting types (softwood, semi-hardwood, and hardwood) were used, and three rooting media (sand, vermiculite, and peat moss) were tested to determine the most effective combination for successful propagation. The experiment was conducted using a completely randomized design with three replications. The results showed significant differences in rooting percentage, root length, number of roots, and survival rate among the cutting types and rooting media. Softwood cuttings exhibited the highest rooting percentage (78.3%), root length (8.5 cm), and number of roots (12.4), while hardwood cuttings had the lowest values for these parameters. In terms of rooting media, sand resulted in the highest rooting percentage (75.6%), followed by vermiculite (67.2%) and peat moss (59.8%). The interaction between cutting type and rooting media was found to have a significant impact on the rooting characteristics of African black pepper. Softwood cuttings performed best when rooted in sand, while semi-hardwood cuttings showed better results in vermiculite. Hardwood cuttings had the highest survival rate when rooted in peat moss. These findings suggest that the choice of cutting type and rooting medium is crucial for successful vegetative propagation of African black pepper. Overall, this study provides valuable insights into the propagation techniques for African black pepper, emphasizing the importance of selecting the appropriate cutting type and rooting medium to achieve optimal rooting and survival rates. The results of this research can be utilized by farmers and horticulturists to improve the efficiency of propagating African black pepper plants, ultimately contributing to increased production and sustainability of this valuable crop.

Thesis Overview

1.0 INTRODUCTION    

   Piper guineense L. commonly referred to as African black pepper is a climbing perennial plant of the family Piperaceae.The plant belongs to the group of pepper called false cubebs (Buzzanell and Gray, 1995) and the berries are often used as substitutes for the edible black pepper (Piper nigrum) and for the most closely related cubebs pepper (Piper cubeba).

African black pepper is a native of tropical region of central and western African and is semi-cultivated in countries such as Nigeria where the leaves and fruits (berries) are sold in markets as condiment and also for food flavor (Joan and Michihol, 2013). It is known as ‘Uziza’ in Igbo and ‘Iyere’ in Yoruba, other common names are Benins pepper, Guinea pepper and False cubeb. It grows in evergreen rainforest edges usually in wet places, gallery forest along rocky rivers of an elevation of 750-1650mm. The leaves have pungent taste and pleasant aroma when crushed (Tapsell and Hemphill, 2006). The oleiferous leaves are elliptic in shape, about 5cm long and 7cm broad. The leaves have a peppery taste, pale greenish colour when fresh and darker green when dried. The flowers are small, borne on common stalks as cluster opposite the leaves or at the terminals of the stem and branches. The African black pepper is a protogynous plant. The flower develop first in the androecium (male organ of the flower) than in the gynoecium (female organ of the flower) (Okigbo and Igwe, 2007). Stamens open up 5-8 days after the stigma is receptive. In Nigeria, African black pepper is highly spicy plant and parts of the various plants are cultivated for their aromatic pungent. They are also classified into tiny wild fruits, nuts, herbs and leafy vegetable having heart-shaped leaves and oval petiole (Iwara and Uboh, 2013).

The various parts of the plants are used for traditional medicine (Koffa et al., 2013). The seeds are widely used as spices. In addition, the seeds are stomachic and carminative especially for griping stomach aches. Piper guineense seed extracts has also been proved effective against Dermestes maculates (Deeger) infestation in the storage of dried fish (Amusan and Okorie, 2002). Extracts of Piper guineense according to Srinivasan, (2000) has been reported to enhance digestion of food by stimulating secretion of digestive enzyme, pancreatic amylase, trypsin and chymotrypsin and is therefore used for the treatment of digestive disorder.

Vegetative propagation is the easiest and fastest way of domesticating fruit trees. It is widely used in propagating high quality cultivars for commercial production. It enhances yield quality and preserves the traits of plants (Jan, 2001). Vegetative propagation however has an important role to play since it involves asexual reproduction through the regeneration of tissues from plant parts. However, there are several methods of vegetative propagation such as cutting, grafting, layering, budding and micropropagation but the method to use depends on the crop species and the intention of the propagator. Since seed germination has been the only known natural way of propagating African Black Pepper; the vegetative propagation of this endangered species needs to be properly evaluated.

This present study therefore is aimed at investigating the rooting potential of African Black Pepper (Piper guineense L.)  Stem cuttings under green house condition using various propagation media such as topsoil, water and carbonized rice husk (CRH).

The major objective of the study is to evaluate the effects of cutting type and different rooting media on the vegetative propagation of African Black Pepper (Piper guineense L.). The specific objectives are as follows:

1. To evaluate the rooting ability of both softwood and hardwood stem cuttings of African Black Pepper (Piper guineense L.).
2. To evaluate the effects of topsoil, water, carbonized rice husk in the vegetative propagation of Piper guineense L.