ABSTRACT
Studies were carried out at the Department of Crop science, University of Nigeria Nsukka
(UNN) to evaluate botanicals control of diseases associated with growth and germination of
Moringa seeds. Five accessions of Moringa seeds collected from Imo, Enugu, Kogi, Plateau and
Kaduna states of Nigeria were used. The following experiments were carried out: seed viability
test, isolation of fungal pathogens, determination of phytochemicals, in vitro control of the
pathogens with six botanicals, phytoxicity test of the botanicals on M. oleifera seeds and early
growth study of the treated and untreated seeds. The viability test revealed significant (p < 0.05)
differences in some of the germination traits of the five accessions of moringa seeds. Kaduna
accession gave the highest number of days to first germination (approx. 6 days) followed by Jos
and Imo with same value (approx. 4 days) and the lowest was Nsukka (approx. 3 days). The
following organisms were isolated from the seed coats; namely, Aspergillius niger, A. flavus, A.
glaucus, Fusarium oxysporium, Mucor spp, Cunnighamella spp, Penicillium digitatum. Only A.
flavus was isolated from the cotyledon (seed without coat). The percentage disease incidence was
highest in Kaduna (99.90%) on seed with coat and (89.75%) on seed without coat. Enugu
accession had the lowest percentage disease incidence (10%) and (0%) for seed with coat and
those without coat respectively. Aspergillius flavus had the highest percentage frequency of
occurrence (16.31%) while the value for Fusaruim oxysporium and Mucor spp were lowest and
statistically the same (0.27%). At both 50 and 70 grams/liter levels of concentration, Aspilia
africana leaf extract showed the highest percentage growth inhibition for 14 days while the
lowest was obtained in Cassia alata. Phytotoxicity test revealed that at 50 grams/liter O.
gratissemum leaf extract significantly ( p < 0.05) gave the highest number of days to first
germination (approx. 6 days) while A. africana leaf extracts gave the lowest (approx. 4 days).
The main effects of Aspilia africana leaf extract treatment on plant height, stem girth, number of
leaves, number of buds and number of nodes were significant (p , 0.05). The seedlings treated
with Aspilia africana leaf extracts at 12 weeks after planting had higher plant height, stem girth,
number of leaves, number of buds and number of nodes than the untreated. (Treated: 59.61, 3.21,
17.90, 4.51 and 18.18 cm) while the untreated gave lower values (untreated: 54.58, 3.19, 16.60,
4.27 and 15.89 cm) respectively. The duration of storage significantly (p < 0.05) affected the
incidence of diseases on the fresh and stored Moringa oleifera leaf products. Two months of
storage gave the highest percentage disease incidence (19.66%) which differed significantly (p <
0.05) from others. Zero storage (at harvest) gave the lowest value (0.92%). The result of the
study shows that all the leaf extracts inhibited the growth of the fungal isolates but Aspilia
africana leaf extract was more effective because it gave relatively less adverse effect to
germination and growth of the Moringa oleifera seeds tested.
TABLE OF CONTENTS
Title page …………………………………………………………………………………………………. i
Certification……………………………………………………………………….………………ii
Dedication……………………………………………………………………………………… iii
Acknowledgements…………………………………………………………………..………….. iv
Table of Contents…………………………………………………………………………….. . v
List of Tables………………………………………………………………………………….. vi
Abstract……………………………………………………………………………………………ix
Introduction…………………………………………… ………………………….………..….…1
Literature review………………………………… …… ……………………………….…..…… 4
Materials and methods…………………………… ……… …………………………………………………13
Experimemt one ………………………………………………………………………….…….. 13
Experimemt two……………………………………………………………….……………………16
Experimemt three…………………………………………………………………………………20
Experimemt four………………………………………………………………………….………21
Experimemt five…….………………………………………………………….…………………22
Results………………………………………………………… … ……………………….… 24
Experimemt one ………………………………………………………………………….…….. 24
Experimemt two……………………………………………………………….……………………30
Experimemt three…………………………………………………………………………………32
Experimemt four………………………………………………………………………….………55
Experimemt five……………………………………………………………….…………………69
Discussion…………………………………………………………………………..…………. . 74
References………………………………………………………………………………………. 79
CHAPTER ONE
INTRODUCTION
Moringa oleifera Lamarck belongs to the family of Moringaceae which consists of 13
species of deciduous trees (Keay, 1989; Price, 1985). Other species of Moringa in the family are
M. arborea, M. berzian, M. concanensis, M. drouhaddi, M. hildebrandtii, M. longituba, M.
ovalifolia, M. peregrina, M. pygmaea, M. rivae, M. ruspoliana and Moringa stenopetala.
Moringa oleifera is the most cultivated among all the species in the family Moringaceae. It is a
native of India but is widely distributed in many tropical and pacific regions, in West Africa as
well as Central America and the Caribbean (Freiberger et al., 1998; Locket et al., 2000;
Ramachandran et al., 1980 and Aregheore, 2002).
The common name of Moringa oleifera is Moringo in Malabar (a region in southern
India) and it is believed to be the origin of the generic name (Jackson, 1990). It appears to have
more names than any plant ever studied. It is known as Rawag in Arabic, Kelorin in Indonesian,
Horse- radish tree, Drumstick tree in English (Hutchinson and Dalziel 1966), Ewe igbale (Ewe
ile) in Yoruba, Zogallagandi (Zogalle) in Hausa, Okwe oyibo in Igbo (Gbile, 1984). The
common names are Miracle tree, Life saver, Never die, etc. (Ofor et al., 2011). Every part of
Moringa plant is useful; the root, seed, leaf, etc. (Fahey, 2005) and may be consumed raw,
roasted, cooked, and processed domestically or industrially. The products of this tree have been
reported to be useful to nutritionists, animal scientists, pathologists, entomologist,
environmentalists, practitioners of natural medicine, etc. (Ofor et al., 2011).
Ogwo and Ogbonnaya (2010) presented Moringa oleifera as one of the few plants that
have the capacity to meet the millennium goals in Nigeria in terms of food security. This is in
response to the prediction of the Food and Agriculture Organization (FAO) that the world
population may rise to about 10 billion in 2050. By 2008 statistics, almost 40% of the world
population lived within the tropical zone and by 2060, 60% of the human population will be in
the tropics due to high birth rates and migrations (Wikipedia, the free Encyclopedia, 2012).
There is a need to increase production of useful plants like Moringa to ensure food security in the
tropics. Though Moringa tree is widespread throughout the tropics, around farms and compounds
and often used as fence especially in northern Nigeria, not much has been done to enhance its
large scale production to ensure sustained availability (Ofor et al., 2011). One of the major
challenges of large scale production is how to handle the pests and diseases of the plant. Farmers
generally suffer great loss through pests and diseases especially through fungal infections which
may not only inhibit the production of foliages, fruits and stems, but lower the overall quality
2
and quantity of the cultivated crops. The known pests are caterpillars, budworms, borers and fruit
flies. Most of the reported diseases of Moringa oleifera are fungal. They are
• The root rot (Diplodia spp)
• The papaya powders mildew (Levellula taurica (Lev) Arn)
• Pod rot disease (Drechslera haraiiensis)
Fungi are significant destroyers of foodstuffs, vegetables and grains during storage
rendering them unfit for human consumption by retarding their nutritive value and often by
producing mycotoxins (Janardhana et al., 1998; Marin et al., 1999). A significant portion of the
agricultural produce in some countries and the world over become contaminated by fungus
infected grains (Janardhana et al., 1998). The main toxic effect of fungi is genetoxicity,
hapatoxicity, nephrotocity, carcinogencity, terratogencity, reproductive disorder and immune
suppression (Hacey, 1988). More than 25% of the world cereals are contaminated with known
mycotoxin and more than 300 fungi metabolites are reported to be toxic to man and animals
(Galvano et al., 2001). A sizeable portion of the world population living below poverty line in
the developing and under developed countries of Asia and Africa are suffering from health
problems associated with consumption of contaminated grain and cereals (Majunder et al.,
1977).
Plant disease invasion started when man began to devastate the ecosystem and then broke
the food chain in ecology and that led to food shortage and famine across the world (Walker,
1969). The increase in demand for moringa and its products has undoubtedly increased the rate at
which the plant is moved from one locality to another and this may contribute to more
imbalances in ecosystem and may also mean exposition of these localities to new diseases. India
had been enjoying disease free farming of Moringa except mild attacks of Diplodia spp. which
occurs mainly in water logged conditions but recently, the threats of Drechslera haraiiensis and
its rot ravages is described as a new disease in India. Its symptoms are observed all over the
surface of the pods, more conspicuously at the stigmatic end. On the green pod, elliptical or
elongated sunken spots with reddish brown raised margins can be observed. Diseased pods are
shrunken to thinner dimensions at their stigmatic ends than healthy ones. In advanced stages of
the disease development, the pods are rotten and dried up prematurely leaving uneven raised
spots over them.
3
Plant is the major source of world food. However, it competes with about 80,000 to
100,000 plant diseases caused by pathogenic organisms such as viruses, bacteria, mycoplasmalike
organisms, rickettsia, fungi, algae and parasitic seed plants. About 3,000 species of
nematodes attack plants and over 800, 000 species of insects of which about 10,000 species are
more devastating and can cause various economic losses in crop production worldwide (George,
1978). Losses caused by pests and diseases in the field have been estimated by the Food and
Agriculture Organization (FAO) to be about 20 to 40% in the developed countries and may be
higher in the developing countries (FAO, 1981). The issues of providing efficient and effective
control of these diseases are a great challenge to the farmers. Though, the seed born fungi could
be controlled efficiently with pesticides but it is at the consumers risks because some pesticides
are toxic to man and animals. It is reported that the world health organization (WHO) banned
many agricultural fungicides due to their wide range of toxicity on non-target organisms
including humans and are known to contribute to environmental pollution (Bernard et al., 1997).
Alternatively, it is also known that plants extract exhibit anti-bacterial, antifungal and
insecticidal properties (Satish et al., 1999). These plant extracts could be preferred to the
conventional fungicides and pesticides because they are mild in nature, friendly to man, livestock
and plants and at the same time effective control for fungal diseases.
Generally, it is observed that some Moringa seeds when the coats are removed, contain
kernels that look brown with signs of decay, some are eaten up. It may be dangerous for those
that eat it raw with the seed coat. That means that whether infected or infested it is still
dangerous. These abnormalities can be as a result of pathogen attack in the field or in the store
due to poor storage or poor handling from the farmers to the consumers.
Therefore, in response to these challenges, the objectives of this study are to:
• isolate and identify some of the disease organisms associated with the seed to
ensure good health and boost the crop yield;
• determine the phytochemical contents of six botanicals for the control of the
disease organisms;
• determine the efficacy of the six plant extracts in the management of the disease
organism;
• determine the effect of the botanicals in the growth of Moringa oleifera seedlings
in the nursery and
• determine the persistence of the organism on the Moringa oleifera leaf product.
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