1. business and industrial
2. agriculture and forestry
3. crops and seed

The fungicidal activity of Neem seeds powder
and Usher leaves powder against
Macrophomia phaseolina causal of
charcoal-rot of sorghum and potato
By
ELRIAH MOHAMED ELHASSAN ALI
B.Sc (Agric.) Alexandria
Egypt (1982)
A
thesis presented in partial fulfillment for the
Degree of Master of Science (Agric.)
(Plant Pathology)
Supervisor
Prof. Ahmed Mohamed Baghdadi
From the
Department of Crop Protection
Faculty of Agriculture
University of Khartoum
2003
Dedication
To my family
With love
ii
CONTENTS
Page No.
Dedication
Acknowledgments
Abstract
List of Tables
List of Figures
List of Plates
ii
v
vi
viii
x
xi
Chapter One
1. Introduction
1
Chapter Two
2. Literature Review
2.1 The fungus
2.2 Distribution of the fungus
2.3 Economic importance
2.4 Host range of the fungus
2.5 The disease
2.6 Symptoms
2.7 Pathology of Macrophomia phaseolina
2.8 Physiological studies
2.8.1 Effect of temperature on growth of different
isolates of M. phaseolina
2.8.2 Effect of relative humidity on growth of
pycnidiospoes
2.9 Control of of M. phaseolina
2.9.1 Cultural practices
2.9.2 Chemical control
2.9.3 Biological control
2.9.4 Control with natural pesticides
2.9.4.1 Neem tree (Azadirachta indica A. Juss)
A.
Description and classification
B.
Distribution
C.
Chemistry of Neem
D.
Neem’s effectiveness
2.9.4.2 Sadom apple, Usher (Calotropis procera)
A.
Description and classification
B.
Distribution
iii
5
5
6
6
7
8
9
10
10
10
11
11
11
12
13
14
14
14
14
14
15
15
15
16
Page No.
Chapter Three
Materials and Methods
3.1 Source of isolation
3.2 Pathogenicity of M. phaseolina
3.2.1 Laboratory experiment
3.2.2 Glasshouse experiment
3.2.2.1 Seed inoculation
3.2.2.2 Soil inoculation
3.3 Preparation of natural products
3.3.1 Neem seeds powder
3.3.2 Sadom apple (Usher) leaves powder
3.4 Control experiment
3.4.1 Control with Neem seeds powder
3.4.2 Control with Usher leaves powder
17
17
17
17
18
18
18
18
18
19
19
19
19
Chapter Four
Results
4.1
4.2
4.3
Isolation of M. phaseolina
Pathogenicity test
Control of M. phaseolina in potato
21
21
42
Chapter Five
Discussion
54
References
57
Appendices
61
Arabic Abstract
85
iv
ACKNOWLEDGEMENTS
I would like to express my sincere gratitude and
thanks to my supervisor Dr. Ahmed Mohamed Baghdadi
for his guidance, keen interest and continuous
participation throughout this study.
Grateful thanks are due to Mr. Osman Elhag Nasr
for his guidance and help. Thanks are extended to Mr.
Ahmed Hamza and Mr. Abd Elmaty for their help.
I am also grateful to all members of the Plant
Protection Directorate, colleagues and friends for their
help and cooperation.
Thanks are also extended to Mr. Salah Mohamed
Osman for typing the manuscript.
v
ABSTRACT
The present work is concerned with the fungicidal activity of
Neem
seeds
powder
and
Usher
leaves
powder
against
Macrophomia phaseolina causal of charcoal-rot disease of
sorghum and potato. The study includes isolation of the pathogen
from seeds of sorghum and tubers of potato.
The two isolates of M. phaseolina were found to incite the
typical symptoms of charcoal-rot disease on the two hosts
(sorghum and potato). The damage caused by these isolates on
the two crop plants indicated that the isolates are not specific.
In pathogenicity tests, high rates of disease incidence were
recorded in the two hosts. In the most cases, the isolates caused
significant reduction in plant height and root length of the two
crop plants. However, no significant reductions were recorded,
probably due to the fact that, the isolates were maintained for one
season only and new isolations had to be made in the second
season. In addition, there is a possibility that the two methods
adopted for inoculation had different efficiencies in establishing
infection.
In the laboratory experiments, potato tubers appear to be
susceptible to the fungus with any inoculation method used. The
potato isolate seem to be most virulent in potato tubers.
vi
The experiments of control for the fungus with Neem seeds
powder showed remarkably effective against soil-borne M.
phaseolina, while the Usher leaves powder performed less than
the Neem seeds powder under pot conditions. However, there is
more than one aspect of the study that need more investigation,
for instance, different harvesting and handling of potato and the
other cultural practices should be evaluated.
vii
LIST OF TABLES
Page No.
Table
1.
Effect of the two isolates of Macrophomia phaseolina
on the height of sorghum plants (season 1999/2000)seed inoculation
24
2.
Effect of the two isolates of M. phaseolina on
the height of sorghum plants (season 2000/2001)seed inoculation
25
Effect of the two isolates of M. phaseolina on
the height of sorghum plants (season 1999/2000)soil inoculation
26
Effect of the two isolates of M. phaseolina on
the height of sorghum plants (season 1999/2000)soil inoculation
27
Effect of the two isolates of M. phaseolina on
the height of potato plants (season 1999/2000)tuber inoculation
28
Effect of the two isolates of M. phaseolina on
the height of potato plants (season 2000/2001)tuber inoculation
29
Effect of the two isolates of M. phaseolina on
the height of potato plants (season 1999/2000)soil inoculation
32
Effect of the two isolates of M. phaseolina on
the height of potato plants (season 2000/2001)soil inoculation
33
Effect of the two isolates of M. phaseolina on
the root length of sorghum and potato plants
(season 1999/2000 and 2000/2001)-through
soil inoculation
34
3.
4.
5.
6.
7.
8.
9.
viii
Page No.
Table
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
Effect of the two isolates of M. phaseolina on
the root length of sorghum and potato plants
(season 1999/2000 and 2000/2001)-through
seed inoculation
36
Pathogenicity of M. phaseolina isolates tested
in tubers of cv. Alpha
38
Effect of the Neem seeds powder against
M. phaseolina on the height of potato plant
(season 2000/2001)
44
Effect of the Neem seeds powder against
M. phaseolina on the height of potato plant
(season 2001/2002)
45
Effect of Usher leaves powder against
M. phaseolina on the height of potato plant
(season 2000/2001)
46
Effect of Usher leaves powder against
M. phaseolina on the height of potato plant
(season 2001/2002)
47
Effect of the Neem seeds powder against
M. phaseolina on the fresh and dry weights
of potato plant
48
Effect of the Usher leaves powder against
M. phaseolina on the fresh and dry weights
of potato plant
49
Effect of the Neem seeds powder against
M. phaseolina on the final tubers yield of
potato plant
51
Effect of the Usher leaves powder against
M. phaseolina on the final tubers yield of
potato plant
52
ix
list of figures
Page No.
Figure
1.
2.
3.
4.
Effect of two isolates of Macrophomia
phaseolina on the height of sorghum and
potato plants
31
Effect of two isolates of M. phaseolina on the
root length of sorghum and potato plants
37
Effect of Neem seeds powder and Usher
leaves powder against M. phaseolina on
the fresh weight of potato plant
50
Effect of Neem seeds powder and Usher
leaves powder against M. phaseolina on the
final tubers yield of potato plant
53
x
LIST OF PLATES
Page No.
Plate
1.
2.
3.
4.
5.
Potato tuber naturally infected with
Macrophomia phaseolina showing
symptoms
30
The mycelia of the fungus and the formation of
the pycnidiospore in the PDA+Rose-bengal
35
Sclerotia of M. phaseolina are smooth, hard
and black in colour
39
Effect of two isolates of M. phaseolina on the
height of potato plant
40
Effect of two isolates of M. phaseolina on the
root of potato plant
41
xi
‫ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ‬
‫دراﺳﺔ ﻟﻤﻌﺮﻓﺔ ﺗﺄﺛﻴﺮ ﻧﺒﺎﺗﻰ اﻟﻨﻴﻢ واﻟﻌﺸﺮ ﻋﻠﻰ‬
‫ﻓﻄﺮ ‪ Macrophomia phaseolina‬اﻟﻤﺴﺒﺐ‬
‫ﻟﻤﺮض اﻟﺘﻔﺤﻢ ﻓﻰ اﻟﺬرة واﻟﺒﻄﺎﻃﺲ‬
‫إﻋﺪاد‬
‫اﻟﺮﻳﺢ ﻣﺤﻤﺪ اﻟﺤﺴﻦ ﻋﻠﻰ‬
‫ﺑﻜﺎﻟﻮروﻳﻮس زراﻋﺔ )أﻣﺮاض ﻧﺒﺎت(‬
‫ﺟﺎﻣﻌﺔ اﻹﺳﻜﻨﺪرﻳﺔ )‪(1982‬‬
‫أﻃﺮوﺣﺔ أﻋﺪت ﻟﻨﻴﻞ درﺟﺔ اﻟﻤﺎﺟﺴﺘﻴﺮ ﻓﻰ اﻟﺰراﻋﺔ‬
‫)أﻣﺮاض ﻧﺒﺎت(‬
‫إﺷﺮاف‬
‫ﺑﺮوﻓﺴﻴﺮ أﺣﻤﺪ ﻣﺤﻤﺪ ﺑﻐﺪادى‬
‫ﻗﺴﻢ وﻗﺎﻳﺔ اﻟﻤﺤﺎﺻﻴﻞ‬
‫آﻠﻴﺔ اﻟﺰراﻋﺔ‬
‫ﺟﺎﻣﻌﺔ اﻟﺨﺮﻃﻮم‬
‫‪2003‬م‬
‫‪xii‬‬
CHAPTER ONE
INTRODUCTION
Sorghum [Sorghum bicolor (L.) Moench] is a hardy plant
able to grow and yield under a wide range of climatic and soil
conditions in the warmer areas of the world. It is not surprising
that many consider it to have been one of the first grasses
cultivated for grain in the early civilization of the warm eastern
Mediterranean region. From the very great diversity of sorghum
types present in Kordofan, the central province of the Sudan, it
has been suggested that this region was the original home of
sorghum, and all imported and Sudanese sorghum seemed to
have
their
counterparts
in
this
area
(Evelyn,
1951).
An
outstanding character-stic of sorghum is its ability to produce
grain under conditions too severe for most other cereals,
particularly so in hot, dry climates and in soil of relatively low
moisture content.
In Sudan, sorghum is the staple food crop and the oldest
and most widely adapted and grown in Sudan. It occupies
annually an area of about twelve million feddans. It constitutes
more than 75% of the total area for cereal production. The crop
productivity, however, constrained by use of low yielding
varieties and poor crop management. During the period 19771992, several improved sorghum cultivars, including varieties
such as Dabar-1-1, Gadam Hamam-47 (Mahmoud, 1977).
Mugawim Buda 1 and 2, Ingaz and Feterita Wad Ahmed
(Osman and Mahmoud, 1992), and hybrids namely Hageen
Dura-1 (HD-1) and Sheikan (ARC/ICRISAT, 1983; Osman and
Mahmoud, 1992) have been released by the Agric-ultural
Research Corporation (ARC) of the Sudan for commercial use
in the irrigated and the rainfed sorghum production systems.
xiii
Sorghum in Sudan is cultivated as a rainfed crop. It is well
known as the rain dura and it is divided into traditional sector and
modern sector, where the machines are used. Most of the
cultivated sorghum is in the rainfed-mechanized sector (Anon,
1978). Gadarif, Damazin, Dalang, Rank and Kosti are recorded as
the most productive areas in sorghum. The crop is also grown
under flood irrigation in the Gash and Tokar Deltas.
The effect of diseases of sorghum on the market value of the
grain was found to be great. Sorghum is very susceptible to
fungal diseases. Seed plays a vital role for healthy production of
crop. They are known to carry pathogens, which cause heavy
yield losses in economic crops (Agarwal et al., 1973).
On sorghum Macrophomina phaseolina can be responsible
for a complex of symptoms including seedling blight, dampingoff, root-rot, and dry rot of stalks, in all leading to poor stands,
stunted plants and lodging accompanied by decreased yield and
inferior, shrunken grain. However, the incidence of the disease is
often sporadic and governed largely by soil and climatic factors,
particularly temperature and rainfall.
Potato [Solanum tuberosum (L.)] is the world’s fourth most
important crop, after rice, wheat and maize. It is grown chiefly in
the temperate zone. Potato belongs to family Solanaceae. This
family also includes several plants, which are of high food value.
The genus Solanum, which includes the potato, comprises about
2000 species (Hawkes, 1944). Nearly 200 of these are tuber
bearing (Whitehead et al., 1953). The plants belonging to the
genus are mostly herbs and shrubs; a few are small tree.
In its original home, in South America, potatoes are grown in
the cooler temperate regions of the Andes Mountains in
xiv
Venezuela, Colombia, Ecuador, Bolivia and North Argentina,
where sufficient moisture is available. It grows best under longday condition (Mohamed, 1986).
Like a great many of the world’s major agricultural products,
potatoes have attained their widest use and importance in lands
far from their place of origin. They were first introduced into
Europe by the Spaniards in 1570 and have been selected and
adopted over the years for their growing condition in the cool
climate countries. The potato has made very little progress in the
world’s hunger belt, where it could add substantially and
advantageously to the food supplies with its high food yield per
feddan, its ample carbohydrate content, well-balanced protein
and high levels of vitamins C and B (Mohamed, 1986).
The potato was introduced in Sudan around 1920 and grown
in scattered land strips in the outskirts of Khartoum North city
(Omer, 1986). Potato production in Sudan in the past was
confined to small limited areas north of Khartoum. The main
production areas are north of Khartoum along both bank of the
Nile in Shendi and Atabra areas, Jebel Marra in western Sudan,
Tokar and Gash Deltas in eastern Sudan. In the recent years,
however, potato has become one of the most popular vegetable
crops eaten by the Sudanese, especially in central Sudan. The
area under cultivation has been steadily increasing, and at
present the total area of production is about 5600 feddan with an
average yield of about 6 tons per feddan (Mohamed, 1986).
During the season 1983/84, it was found that potato fields
grown by Alpha cv at El Bagair scheme were having a high
percentage of infection with the fungus Macrophomia phaseolina
(Mukhtar, 1987). The importance of this pathogenic fungus on
xv
potato has been shown previously by Watson (1943); Young
(1949); Roger (1953) and Pushkarnath (1976). It causes seedlingrot, root-rot, stem-rot and charcoal-rot in dry humid areas.
xvi
CHAPTER TWO
LITERATURE REVIEW
2.1 The Fungus
The fungus Macrophomia phaseolina is a weak pathogen
and generally only attacks young plants. The fungus has a very
wide host range (Atherton and Rudich, 1986).
The selected stage of the fungus first named Sclerotium
bataticola (Taubl.) was later transferred under Rhizoctonia, as R.
bataticola (Tub.) Butler. The pycnidial stage was described by
Maublanc (1905) as Acrophobia phaseolina (Maubl) and later as
Macrophomina phaseolina (Maubl) Ashby by Ashby (1927).
Butler (1918) reported that the fungus known as M.
phaseolina was in fact Rhizoctonia. He based his identification on
the occasional occurrence of what were considered to be clamp
connections, structure characteristics of Basidiomycetes, and
gen-eral similarity of the mycelium to that of Rhizoctonia solani.
The fungus M. phaseolina in culture have young hyphal
growth, which is colourless, about 8.4 in diameter, and with characteristic branching. The branches laying almost parallel to the
parent hyphae with constriction at the point of union. Older
hyphae are thin, septate, brown, with almost right-angled
branching. Sclerotia become visible in 2-3 days. These arise by
repeated division and branching of the hyphal cells. The mature
sclerotia are smooth, hard, shiny, black bodies, which may reach
a size of 100 µ or more on woody plants. Pycnidia of M.
phaseolina occur less commonly than sclerotia. Under normal
conditions they have been found in diseased stems of plants
such as jute, sesame, beans and potato (Tarr, 1962).
xvii
Thirumalachur
(1953)
added
that
the
pycnidial
wall
contained several outer layers of dark, thin-walled, angular cells
and
internal
pycnidiospores
layers
of
on
hyaline
hyaline,
cells,
which
non-septate,
produce
the
rod-shaped
conidiophores 10-15 µ in length. The pycnidia and the sclerotia
characteristics of M. phaseolina on different hosts showed
considerable variations.
Thakur (1979) mentioned that the fungus M. phaseolina is
seed and soil borne, and later spreads through air.
Trukensteen and Hooker (1981) reported that the sclerotia
within roots, stems, leaves and fruits are black, smooth, hard and
0.1-1.0 mm in diameter. They are smaller in culture. Pycnidia, dark
brown on leaves and stems, are 100-200 µm in diameter.
2.2 Distribution of the Fungus
The fungus M. phaseolina occurs mainly in tropical regions,
where high temperature and high humidity prevailed. In the
Mediterranean areas, it probably attacks crops at the time when
two climatic factors coincide (Tarr, 1962).
Thirnmalachar (1953) reported that the charcoal-disease of
plants incited by M. phaseolina occurs widely in many countries
causing damage to plants of economic importance.
2.3 Economic Importance of the Fungus
Macrophomina phaseolina occurs widely in many countries
causing severe damage to crops of great economic importance.
The fungal attack results in damping-off, stem rot and low yield.
Ludwing (1925) reported that charcoal-rot occurred in
considerable abundance in South Carolina and losses of 60-65%
have been reported in some cotton fields in Mississippi.
xviii
Tarr (1962) reported that M. phaseolina on sorghum can be
responsible for complex of symptoms including seedling-blight,
damping-off, root-rot-dry, rot of stalks, stunting and lodging of
plants with attendant decreased yields and inferior shrunken
grains. When temperature and rainfall are favourable, the disease
can be very destructive particularly to sorghum. Under such
conditions, seedling-blight and charcoal-rot of stalks can cause
heavy crop losses.
Thirumalachar (1955) and Sahai et al. (1970) reported that in
potato, most commercial cultivars have been found to be equally
susceptible, and the disease is probably present in all tropical
and subtropical countries, where potatoes are grown.
Stem infection, however, is not as important as tuber attack,
which may occur before harvest and in storage, causing serious
losses (Chupp and Cherf, 1960 and O’Brien and Rich, 1976).
2.4 Host Range of the Fungus
Macrophomina
phaseolina,
the
charcoal-rot
disease
pathogn, has a wide host range exceeding 300 plants species
including legume and cereal crop plants (Reichert and Hellinger,
1947; Dhingra and Sinclair, 1977).
Maublanc (1905) has described the Ashy stem blight, caused
by M. phaseolina on bean. Park (1933) stated that the common
mycorrhizal injurious fungus of tea roots was M. phaseolina. In
tropics and subtropics, the woody plants hosts include citrus,
cacao and rubber (Small, 1928).
The plurivorous nature of M. phaseolina enables this fungus
to survive on many alternative hosts in the absence of the crop
hosts,
although
this
nature
of
xix
the
pathogen
limits
the
effectiveness of some cultural management methods such as
crop rotation (Singh et al., 1990).
Tarr (1962) and Singh and Chohan (1972) reported that there
were many host plants susceptible to M. phaseolina, cotton,
sorghum, eggplant, sweet potato, maize, tomato and many
legumes. The fungus attacks sweet potato, grasses, broomcorn,
wheat, barley and other grasses in the Sudan.
2.5 The Disease
Charcoal-rot is caused by the fungus M. phaseolina. It is
common disease of many crops in the tropics. The lower stem of
the plant near the soil line is gradually attacked (Atherton et al.,
1986).
The fungus M. phaseolina is reported to cause a complex
syndrome including; (a) root-rot (Bhowmik and Singh (1977), (b)
charcoal-rot of stem (Pawar et al., 1978), (c) wilt (Bekesi et al.,
1970) and (d) necrotic leaf spot (Chan and Sackston, 1973).
Tarr (1962) reported that the fungus M. phaseolina is the
casual
agent
of
several
syndromes,
viz.,
seedling-blight,
damping-off, leaf-spotting, rotting of different parts of plants.
Hagedron (1991) reported that in legumes, infection is
evident from the seedling to mature plant stage, while in cereals,
infection is usually observed after onset of anthesis. At the
seedling stage infection usually occurs during moist conditions
and at temper-ture above 27°C.
Turkensteen and Hooker (1981) reported that the tubers are
predisposed to infection at temperatures of 32°C or higher. Rot
development is restricted at low temperature (20-25°C), and most
rapid at 36°C and above.
xx
2.6 Symptoms
Thirmalachar
(1953)
reported
that
grey
discoloration
followed by blackening of the stem, which bears numerous
sclerotia of the fungus, are characteristic symptoms of the
disease. In the case of potato, infection symptoms on tubers, first
appear as blackening of lenticels, followed by rotting of the whole
tubers during the storage periods.
Tarr (1962) reported that M. phaseolina enters the plant
through feeding roots and thereafter into the stem. It causes stalk
rot of sorghum consisting initially of brown, scattered lesions
turning at a later stage to dark or black rot of the entire root.
Pushkarnath (1964) reported that the rot is first visible on
the tubers as a black rot, ranging from 2-3 mm in diameter,
surround-ing the light-colored lenticels and the eyes.
Edmunds (1964) reported that M. phaseolina could exist in
hosts without any symptoms; he suggested that latent infection
probably occurs in the crown of most sorghum plants.
The symptoms incited by M. phaseolina were described by
Al-Ani et al. (1970) as early infection, which leads to early death of
the plant, and the infected seedlings develop typical wilt
symptoms.
Ilyas and Sinclar (1974) reported that the fungus M.
phaseolina initially causes a reddish-brown discoloration of the
stem, followed by the production of sclerotia in the host tissue.
Thirumalachar et al. (1977) reported that the most common
symptoms incited by the fungus are the charcoal-rot, wilt, pre-and
post-emergence, damping-off and stem necrosis.
Thrkensteen and Hooker (1981) reported that under hot
conditions, the pathogen can attack potato stems and cause a
xxi
sudden wilt and yellowing. Stem infection is not usually
important. More important is tuber attack, which may occur
before harvest and in storage, causing loss of entire crop. Early
symptoms develop around the eyes, near lenticels and frequently
at the stolon attachment. The skin appears unaffected at first,
with underlying tissue, usually within 1 cm of the surface,
becoming slightly water-soaked and light grey. Cavities filled with
black mycelium and sclerotia form later. Rapidly invaded tubers,
when cut, exhibit semi watery, flabby breakdown, with color
changing from yellowish to pinkish to brown and finally to black.
2.7 Pathogenicity of M. phaseolina
The fungus M. phaseolina when inoculated into potato
tubers produced charcoal-rot symptoms (Thirumalachar (1953).
Moreover, he added that isolates of Macrophomina phaseolina
from different hosts when inoculated on potato stem plants and
incubated at temperature between 28 and 35°C, it produced the
pycnidial stage within a week.
Tompkin and Gardlner (1935) found that strains of M.
phaseolina isolated from different hosts (bean, sugar beet,
cowpea, sweet potato and cotton) were pathogenic to bean and
cowpea only.
2.8 Physiological Studies
2.8.1ffect of Temperature on Growth of the Different
Isolates of M. phaseolina
The isolates of M. phaseolina obtained from seedling stemblight of bean, sugar beet, sweet potato, citrus and cotton
developed
at
temperature
of
25-35°C
with
temperature 31°C (Tompkin and Gardner, 1935).
xxii
an
optimum
Goth and Ostazeski (1965) showed that single pycnidospore
isolated from M. phaseolina isolated from bean sprouted well on
potato-dextrose agar at 27°C.
Smith (1964) reported that the soil temperature strongly
influences plant disease with several soil-borne pathogens
including charcoal-rot disease caused by M. phaseolina.
Singh and Chohan (1972) reported that M. phaseolina
isolated from fruit of Luffa acutangula grow profusely on potatodextrose-agar at 30°C and produced abundant sclerotia.
2.8.2 Effect of Relative Humidity on Growth of Pycnidiospores
Hussein and Ahmed (1960) reported that the pycnidiospores
of the fungus M. phaseolina could germinate at relative humidity
of 46-100% and temperature of 20-40°C. At 100% relative humidity
and 30°C, only 28.4% of the pycnidiospores germinate within 24
hours.
Ahmed (1968) reported that 90% relative humidity is the
minimum relative humidity under which pycnidiospores of the
fungus M. phaseolina could germinate at 30°C.
2.9 Control of Macrophomina phaseolina
2.9.1 Cultural Practices
Turkensteen and Hooker (1981) reported that the cultural
practices are very important to avoid charcoal-rot disease. They
suggested some practices for potato to avoid charcoal-rot
disease:
1-
Harvest early, before soil temperatures become high.
2-
Avoid bruising and wounding of tubers in harvest and
post-harvest handling.
xxiii
3-
Field irrigation may be used to prevent excessive soil
temperature.
4-
Do not harvest during periods in which soil temperature
exceeds 28°C.
5-
Do not leave tubers in soil after harvest.
6-
Do not store tubers at high temperature.
7-
Do not use seeds originated from areas where disease is
frequent.
Francl and Rosenbrock (1988) reported that sorghum-
sorghum rotations were slightly better than sorghum-corn
rotations in lowering M. phaseolina in the soil. These results
suggest that crop rotation among hosts of M. phaseolina may still
be a good option of charcoal-rot management.
2.9.2 Chemical Control
Luttrell and Garren (1952) reported that Ashy stem blight in
beans and leaf-spot were completely controlled by seed-treatment
with 2% Ceresan.
Boyd (1949) reported that formalin appeared to give less
satisfactory control of dry-rot caused by M. phaseolina of treated
tubers. Rath and Mohanty (1978) found that pre-inoculation
treatment with 0.03% formalin was the best among all the
treatment in controlling M. phaseolina in garlic cloves.
Sinha (1976) found that out of nine systemic and nonsystemic fungicides tested for controlling the seed-borne M.
phaseolina in the cowpea seeds, Bavistin and Benomyl were
excellent.
Thakur (1979) reported that the formalin was the poorest in
performance compared to the other non-systemic fungi toxicant
such as Brassicol.
xxiv
Mohamed et al. (1991) found that seed dressing by Captan (3
g/kg seed) was the best to control the infection of soyabean by M.
phaseolina.
Reddy (1991) reported that 5 fungicides tested in vitro,
Carbendazim was the most effective in inhibiting the growth of A.
niger and M. phaseolina followed by Carbenazim + Thiram and
Captan.
2.9.3 Biological Control
Semeniuk (1944) reported that activity of M. phaseolina
under natural conditions was greatly influenced by other
microorganisms present in the soil. For instance, the seedling
disease of maize caused by M. phaseolina was severe in sterilized
soil, but did not occur in inoculated un-sterilized soil, and less
disease resulted from mixed inoculum of M. phaseolina and
Fusarium moniliforme.
Antagonistic
effect
of
Trichoderma
viride
on
fungal
pathogens of a variety of plant diseases has been reported by
several investigators (Dohroo and Sharma, 1984; Rod, 1984;
Abdon et al., 1985; Zimmerman, 1985).
Elad et al. (1986) reported that reduction in charcoal-rot
incidence of greenhouse-planted beans and melons amounting to
37-74%
and
37.5-46.3%,
respectively,
when
Trichoderma
harzianum was completely added to the inoculum.
Ehteshamal and Ghaffar (1993) found that Rhizobium
meliloti inhibited growth of M. phaseolina and R. solani when
used as seed dressing or as soil drench in okra, sunflower and
soyabean in Pakistan.
Hajra et al (1992) found that Pseudomonas sp inhibit the
growth of M. phaseolina.
xxv
Zaki and Mgbool (1993) reported that two isolates of
Verticillum
inhibited
chlamydosporium
the
growth
of
M.
phaseolina on PDA.
2.9.4 Control with Natural Pesticides
2.9.4.1 Neem Tree (Azadirachta indica A. Juss)
(A) Description and classification
The Neem tree Azadirachta indica A. Juss, is member of the
Meliaceae family (Lall et al., 1978). Formerly known as Melia
azadirachta Linn. or Melia indica.
The Neem tree is an ever green, which takes 10-15 years to
become full grown at a height between 12-18 meters. The Neem
tree
does
not
produce
fruit
throughout
the
whole
year
(Radwanski, 1977).
(B) Distribution
The Neem tree is cultivated all over India and Burma. The
Neem was tree introduced to Africa during the last century. It is
now
well-established
in
a
number
of
African
countries,
particularly in the rainfall deficient regions such as the Sahel
zone. The Neem tree is now found in Cameroon, Nigeria, Gambia,
India, Burma, Pakistan, Japan and some other countries of Africa
and central America (Jackson, 1977).
(C) Chemistry of Neem
More than 100 compounds have been isolated from the
various parts of the Neem tree e.g. the seeds, the seeds kernel
and bark. Azadirachta and its relatives are the most biologically
active compounds of Neem followed by less biologically active
groups such as degunin, vepinin, vilasinin, nimbin and salanin
(Schmutter-er, 1995; Jones et al., 1989).
xxvi
(D) Neem’s effectiveness
Neem products have been tested on 133 species of insects,
3 species of mites, 8 species of nematodes and 6 species of fungi
(Kettar, 1976).
Singh and Kataria (1985) reported that plants elaborate
various types of chemicals to defend themselves against insect
and other organisms.
In Sudan, Siddig (1987) reported that Neem seeds and
leaves water extracts at 1 kg/40 liter of water repelled foliage
pests of potato and increased yield.
The Neem seeds water extract was recommended as one of
the components of integrated pest management (IPM) suggested
for control of some potato pests (Siddig, 1993).
Satti (1997) reported that the Neem seeds water extract was
found comparable to the standard insecticide Malathion in
controlling cucumber pests.
Neem seed water extract and organic extracts efficiently
controlled powdery mildew on cucumber as shown by trials
executed by Mukhtar (1997).
2.9.4.2 Sadom Apple, Usher (Calotropis procera)
(A) Description and Distribution
Calotropis procera, locally known as Usher, belongs to the
family Asclepeadaceae. Andrew (1952) described the Usher plants
as a spot woody shrub or small tree up to 18 ft high. Bark is
yellow-brown, thick and corky. Young parts are covered by a
white tomentum, leaves are pale-green, fleshly, sessile or shortly
petiolated. Flowers are in 3-10 flowered subumbles up to 3 inches
xxvii
long. Fruit is green, 3-6 inches long with a thick spongy inflated
pericarp.
(B) Chemistry of Usher
Hesse and Reicheneder (1936) and Sebiet et al. (1982)
reported that the chemical constituents of Usher present in the
aerial parts of the plant include alkaloids, cardiac glycosides,
flavonoides, tannins, saponins sterols and triterpens.
Hesse and Lubwig (1960) reported that some sulfur
containing heart poisons have been in the latex.
Sharma (1934) reported many active principles from
different plant parts of Usher. The latex contains calation,
calotropin, calotoxin, uscharin, voruscharin and calotropagenin.
The seed contain coroglaucigenin.
Gary et al. (1983) showed that the resin from the latex is a
mixture of triterpene esters of a lower aliphatic acid. The
polysaccharide from the leaves isolated by Qudrate et al. (1969).
xxviii
CHAPTER THREE
MATERIALS AND METHODS
3.1 Source of Isolation
Two isolates of Macrophomina phaseolina were used. A
potato [Solanum tuberosum (L.)] isolate was obtained from
diseased tuber potato (Alpha), and the other isolate has been
obtained from diseased seeds of sorghum [Sorghum bicolor (L.)].
The two isolates were picked with sterilized needles and
transferred aseptically to sterilized Petri dishes (9 cm diameter)
containing Potato Dextrose Agar (PDA) medium. The cultures of
Macrophomina phaseolina isolated were incubated at 28°C and
culture characteristics were recorded. Stock cultures from the 7
days-old single spore culture of the two isolates were maintained
under drops of sterilized paraffin oil in McCarteny bottles
containing slants of PDA at 4°C for further investigations.
3.2 Pathogenicity of Macrophomina phaseolina
3.2.1 Laboratory Experiment
The pathogenicity of the two isolates of Macrophomina
phaseolina were tested on initially weighed potato tuber of
approximately similar size (Alpha). Cavities/cm deep were made
into the tuber by sterilized cork-borer (4 mm diameter), and
inocula were placed into injured regions. Then, the removed
tissue of the cavity was restored and the wound was sealed with
wax so as to avoid contamination. The inoculated tubers were
then placed in polythene bags incubated at 28°C. Control tubers
were similarly treated except that no inoculum was added.
Disease development was assessed from the percentage of the
weight losses of the tubers after 7, 14 and 21 days of inoculation.
xxix
3.2.2 Glasshouse Experiment
This experiment was conducted to study the susceptibility
and pathological effects of different isolates of M. phaseolina on
sorghum and potato plants as compared with control. The two
methods of artificial inoculation were used (seed inoculation and
soil inoculation).
3.2.2.1 Seed Inoculation
Healthy potato tubers and sorghum seeds were washed in
sterilized distilled water and divided into two lots. The first lot was
further subdivided into two lots each lot was soaked in a dense
spore suspension of each of the fungus isolates. The other lot
was similarly treated with sterilized water and used as control. A
complete randomized design with four replications and five plants
per pot was adopted for sorghum; potato was grown at half
tuber/pot (Mukhtar, 1987).
3.2.2.2 Soil Inoculation
In this experiment, the soil was inoculated by sand cornmeal culture of the fungus. The sand-corn-meal was prepared in
the proportions of 100 g clean dry sand, 6 g corn flour and 15 ml
distilled water. These materials were mixed in a conical flask (vol.
250 ml) and autoclaved at 20 lb/in3 pressure for 15 minutes
(Ahmed, 1968).
3.3 Preparation of Natural Products
3.1.1 Neem Seed Powder
Mature seeds of the Neem tree [Azadirachta indica (A.) Juss]
were collected from under trees grown for seeds at Soba area.
The collected seeds were washed and left for seven days under
the sun to dry. The dried seeds were first crushed in a mortar to
xxx
remove the shell without damaging the kernels. The kernels were
then ground by electric blender (Moulinex type 276) into fine
powder. The powder was stored in tightly glass jars and left at
room temperature till it was required for bioassay.
3.3.2 Sadom Apple (Usher) Leaves Preparation
Fresh leaves of the Usher (Calotropis procera) were
collected from mature Usher plants found at Elshagara area. The
collected leaves were left to dry at room temperature (32°C). Dried
leaves were first crushed by hand then ground by electric blender
(Moulinex type 276). The obtained powder was stored in tightly
covered glass jar in the laboratory at room temperature till
needed for bioassay.
3.4 Control Experiment
3.4.1 Control with Neem Seed Powder
Healthy potato tubers were washed in sterilized distilled
water. Then the tubers were inoculated with M. phaseolina and
sown one tuber/pot. A complete randomized design with four
replications was adopted. The Neem seeds powder was placed at
rate of 0.5, 1.0, 1.5 and 2.0 g per pot. The first control was
inoculated with M. phaseolina only and the second control was
sown without any inoculation by M. phaseolina or Neem seeds
powder.
3.4.2 Control with Usher Leaves Powder
Usher leaves powder was placed at the rate of 0.5, 1.0, 1.5
and 2.0 g per pot (12 cm diameter). Then healthy potato tubers
were inoculated with M. phaseolina and sown one tuber/pot. A
complete randomized design with four replications was adopted.
The first control was inoculated with M. phaseolina only, and in
xxxi
the second control the potato tubers were washed with sterilized
distilled water only.
xxxii
CHAPTER FOUR
RESULTS
4.1 Isolation of Macrophomina phaseolina
Isolation of the fungus was achieved from diseased potato
tubers and diseased seeds of sorghum. The two isolates of
Macrophomina phaseolina were obtained in pure culture on PDA
medium. The cottony dense mycelia with white grey colour
appeared first, followed by the black colour, which was due to the
formation of the pycnidiospores (Plate 1).
The mycelia were initially white, later the colour changed
into grey to black when seen under the compound microscope.
On the PDA medium, the fungus grew favourably and it covered
the 9 cm plate in about 48-72 hours at 30°C (Plate 2).
The sclerotia could be identified by the aid of the
stereoscopic binocular (16-40 x) or even by the naked eye. The
pycnidiospores of the fungus were single-celled, smooth and
dispersed singly. The infected young seedlings of the two hosts
were completely covered with sclerotia and pycnidia of the
fungus (Plate 3).
4.2 Pathogenicity Test
[A] Glasshouse Experiment
In the case of potato plants grown in the glasshouse, a
sudden wilt and yellowing were observed. The infected young
seedling of sorghum was first wilted, became stunted and later
dried up. The diseased young plants of potato and sorghum
showed
reduction
in
the
root
systems
and
dark-brown
discoloration. The two isolates of M. phaseolina were found to be
pathogenic on the two crops tested (potato and sorghum).
xxxiii
(i) Effect on the Plants Heights
The results on the two isolates of M. phaseolina on the
heights of sorghum plant using seed inoculation method
are
demonstrated in Tables (1) and (2). In the season 1999/2000, the
statistical analysis of the results showed significant difference
between the treatments at the different times of the measurement
(i.e. at 30, 45 and 90 days after planting). Thus, the two isolates
caused significant reduction in the heights of the infected plants
when compared with the control (Appendix II-A and II-B).
The results of the heights of sorghum plant as affected by
the two isolates of M. phaseolina using the soil inoculation
methods are presented in Tables (3) and (4) and Appendix (II-C)
and (II-D). The results of both seasons (1999/2000 and 2000/2001)
showed highly significant differences between the treatments,
and that the heights of the plants were significantly affected by
infection with M. phaseolina.
From potato plants, the results were the highest in season
1999/2000 and 2000/2001 using the tubers inoculations method as
shown in Tables (5) and (6) and Appendix (II-E) and (II-F). The
results obtained in both seasons showed highly significant
differences between the treatments, and the highest of the
infected potato plants were significantly reduced when compared
to the control (Plate 4).
Similar results were also obtained using the soil inoculation
method. In the first season the two isolates of the fungus caused
highly significant reductions in heights of the plants at all times
of the measurement (Table 7). But non-significant differences
between the treatments were obtained in the second season
(Table 8 and Appendix II-G and II-H).
xxxiv
(ii) Effect on Root Length
Measurement of the root length of the seed inoculation and control test plant (sorghum
and potato plants) in season 1999/2000 and 2000/2001 are presented in Table (9) and
Appendix (II-I) and (II-J). The roots of the infected plants were shorter and weaker as
compared with control plants. The statistical analysis of the first season’s results
indicated that there were significant differences between treatments and the two isolates
significantly reduced the root length (Plate 5).
Using the soil inoculation method, however, the differences
in the root length of the two crops obtained in the first season
1999/2000 were non-significant (Table 10 and Appendix II-K and IIL). In the season 2000/2001, significant effect of the fungus
isolates on the root length were produced in case of sorghum, but
not in potato plants.
[B] Laboratory Experiments
In the laboratory, the pathogenicity of M. phaseolina was only studied in
potato tubers. Inoculation with the cork-borer method resulting in even greater tuber
rotting and weight losses in the two weeks after inoculation (Table 14). The faster
progress of the disease was associated with the potato isolate.
xxxv
Table 1. Effect of the two isolates of M. phaseolina on
the
height of sorghum plant (season 1999/2000)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
48.70
67.55
79.73
Potato isolate
56.60
73.25
81.62
Control
60.66
81.20
86.70
Lsd0.05
7.899
7.899
7.899
S.E±
1.64
2.62
2.54
Phaseolina
•
Infection was achieved through seed inoculation.
•
Heights are mean of four replications.
xxxvi
Table 2. Effect of the two isolates of M. phaseolina on
the height of sorghum plant (season 2000/2001)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
49.25
68.50
78.75
Potato isolate
57.55
74.65
82.25
Control
62.75
82.75
88.25
Lsd0.05
7.899
14.606
12.135
S.E±
1.41
3.04
2.53
Phaseolina
•
Infection was achieved through seed inoculation.
•
Heights are mean of four replications.
xxxvii
Table 3. Effect of the two isolates of M. phaseolina on
the height of sorghum plant (season 1999/2000)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
44.65
56.80
67.75
Potato isolate
50.22
61.00
72.47
Control
61.25
76.80
82.65
Lsd0.05
4.208
10.542
10.495
S.E±
0.88
2.20
2.19
Phaseolina
•
Infection was achieved through soil inoculation.
•
Heights are mean of four replications.
xxxviii
Table 4. Effect of the two isolates of M. phaseolina on
the height of sorghum plant (season 2000/2001)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
45.36
54.75
65.25
Potato isolate
51.75
62.67
75.36
Control
64.25
78.82
84.65
Lsd0.05
6.184
9.278
7.172
S.E±
1.29
1.93
1.49
Phaseolina
•
Infection was achieved through soil inoculation.
•
Heights are mean of four replications.
xxxix
Table 5. Effect of the two isolates of M. phaseolina on
the height of potato plant (season 1999/2000)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
39.22
43.30
48.20
Potato isolate
42.16
45.72
46.95
Control
50.60
56.80
62.30
Lsd0.05
4.223
5.650
4.954
S.E±
0.88
1.18
1.24
Phaseolina
•
Infection was achieved through tuber inoculation.
•
Heights are mean of four replications.
xl
Table 6. Effect of the two isolates of M. phaseolina on
the height of potato plant (season 2000/2001)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
41.32
44.65
47.20
Potato isolate
42.60
46.50
49.72
Control
50.80
60.22
68.75
Lsd0.05
3.032
3.322
4.199
S.E±
0.63
0.69
2.54
Phaseolina
•
Infection was achieved through tuber inoculation.
•
Heights are mean of four replications.
xli
xlii
xliii
Table 7. Effect of the two isolates of M. phaseolina on
the height of potato plant (season 1999/2000)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
31.50
35.62
36.77
Potato isolate
32.80
37.42
40.65
Control
42.62
44.80
50.32
Lsd0.05
2.519
3.273
4.146
S.E±
0.52
0.68
0.86
phaseolina
•
Infection was achieved through soil inoculation.
•
Heights are mean of four replications.
xliv
Table 8. Effect of the two isolates of M. phaseolina on
the height of potato plant (season 2000/2001)
Isolate of M.
Height of plant (cm) after:
30 days
60 days
90 days
Sorghum isolate
40.00
44.20
54.35
Potato isolate
42.30
46.60
58.70
Control
50.25
59.85
72.20
Lsd0.05
2.614
2.090
2.503
S.E±
0.54
0.44
0.52
Phaseolina
•
Infection was achieved through soil inoculation.
•
Heights are mean of four replications.
xlv
Table 9. Effect of the two isolates of M. phaseolina on
the root length of sorghum and potato plants
Root length of the test plant (cm)
Isolate of M.
Phaseolina
1999/2000
Sorghu
Potato
m
2000/2001
Sorghu
Potato
m
Sorghum isolate
11.90
12.65
12.65
10.30
Potato isolate
12.80
11.45
13.20
11.45
Control
15.50
15.85
15.75
15.80
Lsd0.05
1.190
1.266
1.557
1.213
S.E±
0.25
0.26
0.32
0.25
•
Infection was achieved through seed inoculation.
•
Figures are means of four replications measured three
months after planting.
xlvi
xlvii
Table 10. Effect of the two isolates of M. phaseolina on
the root length of sorghum and potato plants
Root length of the test plant (cm)
Isolate of M.
Phaseolina
1999/2000
2000/2001
Sorghum
Potato
Sorghum
Potato
12.80
11.50
13.25
11.45
Potato isolate
11.60
10.40
12.95
10.75
Control
16.40
15.60
16.60
15.20
Lsd0.05
1.225
1.283
1.810
1.065
S.E±
0.27
0.27
0.38
0.22
Sorghum
isolate
•
Infection was achieved through soil inoculation.
•
Figures are means of four replications measured three
months after planting.
xlviii
xlix
Table 11. Pathogenicity of M. phaseolina isolates tested in
tubers of cv. Alpha
Isolate of M.
% Weight loss in potato tubers
7 days
14 days
21 days
Sorghum isolate
7.26
8.80
23.75
Potato isolate
8.35
18.43
22.54
Control
0.60
3.26
4.20
Lsd0.05
1.472
2.132
1.139
0.31
0.44
0.86
Phaseolina
S.E±
•
The tubers were inoculated by cork-borer.
•
Control tubers were injured similarly, but no inoculum
was added.
•
Rotted portions are cleaned out after each assessment.
•
Weight losses are mean of four replications.
l
li
lii
liii
4.3 Control of M. phaseolina in Potato
[A] Control with Neem Seeds Powder
(i) Effect on the Plant Height
Measurements of the plants height are presented in Tables
(12) and (13) and Appendix (II-M) and (II-N). The statistical
analysis of the first season (2000/2001) and the second season
(2001/2002)
results
indicated
that
there
were
significant
differences between treatments.
(ii) Effect on the Dry and Fresh Weights
The results of the effect on the dry and fresh weights are
shown in Table (16) and Appendix (II-O). The results showed
highly significant differences between treatments.
(iii) Effect on the Final Tubers Yield
The measurements of the final tubers yield were presented
in Table (18). The statistical results showed highly significant
differences between the treatments (Appendix II-P).
[B] Control with Usher Leaves Powder
(i) Effect on Plant Height
The effect on plants height in season 2000/2001 is presented in Table (14) and in
seasons 2001/2002 in Table (15). The results of the statistical analysis indicated that
there were significant differences between the treatments (Appendix II-Q and II-R).
(ii) Effect on the Dry and Fresh Weights
The results on the effect of dry and fresh weights of potato
plants are demonstrated in Table (17). The statistical analysis of
the results showed significant differences between the treatments
(Appendix II-S).
liv
(iii) Effect on the Final Tubers Yield
The results of the final tubers yield of potato plant are
presented in Table (19). The statistical analysis of the results has
shown significant difference between the treatments (Appendix IIT).
lv
Table 12. Effect of the Neem seeds powder against M.
phaseolina on the height of potato plants
(season 2000/2001)
Height of plants (cm) after
30 days
45 days
60 days
Treatment
M + N-0.5 g
30.45
32.75
33.75
M + N-1.0 g
32.75
36.75
38.01
M + N-1.5 g
33.50
37.75
38.50
M + N-2.0 g
30.60
32.55
33.25
Control (1)
26.70
27.40
26.75
(Control (2)
24.50
31.75
34.75
Lsd0.05
2.166
4.513
4.252
0.24
0.51
0.48
S.E±
•
M = Macrophomina phaseolina
•
N = Neem seeds powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lvi
Table 13. Effect of the Neem seeds powder against M.
phaseolina on the height of potato plants
(season 2001/2002)
Treatment
Height of plants (cm) after
30 days
45 days
60 days
M + N-0.5 g
31.25
33.78
33.50
M + N-1.0 g
33.60
36.12
37.33
M + N-1.5 g
34.75
38.70
39.35
M + N-2.0 g
31.58
33.70
33.10
Control (1)
27.63
28.25
27.80
(Control (2)
24.74
31.50
34.00
Lsd0.05
3.343
2.423
2.618
0.37
0.27
0.29
S.E±
•
M = Macrophomina phaseolina
•
N = Neem seeds powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lvii
Table 14. Effect of the Usher leaves powder against M.
phaseolina on the height of potato plants
(season 2000/2001)
Treatment
Height of plants (cm) after
30 days
45 days
60 days
M + U-0.5 g
32.80
36.50
40.10
M + U-1.0 g
35.70
40.25
38.75
M + U-1.5 g
31.50
37.20
38.75
M + U-2.0 g
29.40
38.20
37.50
Control (1)
24.70
26.75
25.50
(Control (2)
25.75
31.00
34.50
Lsd0.05
2.202
5.244
5.096
0.25
0.59
0.57
S.E±
•
M = Macrophomina phaseolina
•
U = Usher leaves powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lviii
Table 15. Effect of the Usher leaves powder against M.
phaseolina on the height of potato plants
(season 2001/2002)
Height of plants (cm) after
30 days
45 days
60 days
Treatment
M + U-0.5 g
33.91
37.40
37.30
M + U-1.0 g
36.00
41.17
38.00
M + U-1.5 g
32.00
37.00
39.30
M + U-2.0 g
30.00
39.00
36.00
Control (1)
25.13
28.11
25.25
(Control (2)
25.00
30.00
33.25
Lsd0.05
3.930
4.232
6.272
0.44
0.47
0.70
S.E±
•
M = Macrophomina phaseolina
•
U = Usher leaves powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lix
Table 16. Effect of the Neem seeds powder against M.
phaseolina on the fresh weight and dry weight
of potato plants
Treatment
Fresh weight (g/plant)
Dry weight (g/plant)
M + N-0.5 g
7.39
1.26
M + N-1.0 g
8.22
1.46
M + N-1.5 g
10.73
1.64
M + N-2.0 g
8.07
1.59
Control (1)
5.79
0.95
(Control (2)
9.08
1.67
Lsd0.05
0.890
0.202
0.10
0.01
S.E±
•
M = Macrophomina phaseolina
•
N = Neem seeds powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lx
Table 17. Effect of the Usher leaves powder against M.
phaseolina on the fresh weight and dry weight
of potato plants
Fresh weight (g/plant)
Dry weight (g/plant)
M + U-0.5 g
7.75
1.07
M + U-1.0 g
8.98
1.63
M + U-1.5 g
9.25
1.46
M + U-2.0 g
11.10
2.15
Control (1)
6.14
1.42
(Control (2)
10.70
2.26
Lsd0.05
1.047
0.666
0.12
0.08
Treatment
S.E±
•
M = Macrophomina phaseolina
•
U = Usher leaves powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lxi
lxii
Table 18. Effect of the Neem seeds powder against M.
phaseolina on the final tuber yield of potato
plants
Tuber yield/pot (g)
Season 2000/2001
Season 2001/2002
Treatment
M + N-0.5 g
10.74
9.65
M + N-1.0 g
10.78
9.44
M + N-1.5 g
14.95
12.80
M + N-2.0 g
7.91
8.24
Control (1)
3.44
3.45
(Control (2)
4.91
5.60
Lsd0.05
1.324
0.906
0.15
0.10
S.E±
•
M = Macrophomina phaseolina
•
N = Neem seeds powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lxiii
Table 19. Effect of the Usher leaves powder against M.
phaseolina on the final tuber yield of potato
plants
Treatment
Tuber yield/pot (g)
Season 2000/2001
Season 2001/2002
M + U-0.5 g
8.24
7.55
M + U-1.0 g
5.24
6.70
M + U-1.5 g
11.67
10.85
M + U-2.0 g
14.38
15.30
Control (1)
10.27
11.25
(Control (2)
9.67
12.60
Lsd0.05
1.658
1.452
0.19
0.16
S.E±
•
M = Macrophomina phaseolina
•
U = Usher leaves powder
•
Control (1) = inoculation with Macrophomina phaseolina
only.
•
Control (2) = Without any inoculation
lxiv
lxv
CHAPTER FIVE
DISCUSSION
In the present study, two isolates of Macrophomina
phaseolina the agent of charcoal-rot disease, were isolated from
sorghum and diseased potato tubers. The pathogenicity test
showed that the two isolates of M. phaseolina were pathogenic on
the two crops tested (sorghum and potato), and could effectively
be controlled by the Neem seeds powder and Usher leaves
powder.
In the Sudan, the presence of M. phaseolina was reported in
cotton (Tarr, 1956 and Ahmed, 1968), in sorghum (Tarr, 1962) and
in potato (Mukhtar, 1987).
Turkensteen and Hooker (1981) reported that under hot
conditions, the pathogen can attack potato stems and cause a
sudden wilt, but more important is tuber attack before harvest
and in storage, causing loss of the final yield.
The growth analysis of the inoculated plants revealed
pronounced reduction in plant height and root length and losses
in the final yield as compared to that collected from healthy
plants. However, the reduction or loss may be different from year
to year or with different methods of inoculation.
Using the same method of inoculation, the difference in the
results from year-to-year could be ascribed to the fact that each
year new races were isolated from the two hosts. Similar findings
have been reported by Kushi and Khare (1978).
Potato charcoal-rot disease was also observed to cause
great losses in Indian potato crop, reaching an incidence of 75
percent in different states (Thirumalachar, 1955).
lxvi
In the laboratory experiments, potato tubers appear to be
susceptible to the fungus with any inoculation methods used.
Generally, the potato isolates seems to be most virulent in potato
tubers as judged from the rate of disease progress and the
amount of rotted tissue.
The symptoms induced by the M. phaseolina on the two
hosts were similar to those described by Al-Ani et al. (1970);
Thirumalachar (1977); Ilyas and Sinclar (1974) and Pushkarnath
(1964).
In the experiments of control of the fungus with Neem seeds
powder, it was evident from the results that the Neem seeds
powder was remarkably effective against the soil-borne M.
phaseolina, while the Usher leaves powder performed less than
Neem seeds powder under pot conditions. That was clearly
indicated by the rate of disease incidence and the status of the
plants growth. Several investigators working with different crops
have also demonstrated the effectiveness of the Neem and Usher
as fungicides in controlling M. phaseolina and other pests of
potato. For instance, Keltar (1976) reported that the Neem
products have been tested on 133 species of insects, 3 species of
mites, 8 species of nematodes, 6 species of fungi.
In Sudan, Siddig (1987) reported that Neem seeds and
leaves water extracts at 1 kg/40 liter of water repelled foliage
pests of potato and increased yield. Neem seeds water extracts
and organic extracts efficiently controlled powdery mildew on
cucumber as shown by trials executed by Mukhtar (1997).
In this study, it was apparent from the cross inoculation
experiment that the two isolates of M. phaseolina under study
were not specialized parasites as they could equally infect the
lxvii
two hosts. It is evident from the above study that charcoal-rot of
potato can be effectively controlled by Neem seeds powder as
fungicide and significantly minimized by the Usher leaves
powder.
However, there are more aspects of the study that need
more investigation. For instance, as the infection starts from the
field, different harvesting and handling methods of potato should
be evaluated. Other cultural practices such as planting dates,
clean seeds, … etc; on the incidence of charcoal-rot disease of
different crops in the Sudan need to be examined.
M. phaseolina is soil-borne and often found associated with
soil adhering to the tubers. So study of the role of soil inoculum
on the development of the rot is very important.
lxviii
REFERENCES
Abdon, Y.A.M.; Elsharkawy, T.A.; Osman, A.R. and Ragab, M.M.
(1985).
In-vitro
test
for
the
control
of
Sclerotinia
solerotiorum. Egyptian Journal of Phytopathology, 14:87-92.
Agarwal, V.K.; Mathur, S.B. and Neergaard, P. (1973). Some
aspects of seed health testing with respect to seed-borne
fungi of rice. Indian Phtopath., 25:91-100.
Ahmed, M.S. (1968). Studies on cotton stem canker caused by
Macrophomina phaseolina (Maulb) Ashby in the Sudan.
M.Sc. Thesis, University of Khartoum, Sudan.
Al-Ani, H.Y.; Natour, R.M. and El-Behadli, A.H. (1970). Charcoal-rot
of sesame in Iraq. Phytopath. Mediterranean, 9(1):50-53.
Andrews, F.W. (1952). Description of Usher plant character. The
flowering plants in Sudan, vol. 11:404.
Anon (1978). FAO Production Yearbook. Vol. 32:107-108.
ARC/ICRISAT Collaboration Sorghum Improvement Programme
(1983). Application for release of the first sorghum hybrid in
Sudan. Proceedings of Technical Committee for Plant
Propagation and Variety Release, ARC, Sudan.
Ashby, S.F. (1927). Macrophomina phaseolina (Maubl) Comb. Nov.
The pycnidial of Rhizoctonia bataticola (Taub) Bull. Trans.
Brit. Mcol. Soc., 12:141-147.
Atherton, J.G. and Rudich, J. (1986). The tomato crop, A scientific
basis for improvement. PP:455, 661.
Bekesi, P.; Voros, J. and Calvert, O.H. (1970). Macrophomina
phaseolina in Hungary sunflower. Plant Disease Report,
51:286-287.
lxix
Bhowmik, T.P. and Singh, (1977). Combined effect of Rhizoctonia
root-rot and Alternaria leaf blight on sunflower. Indian
Phytopathology, 30:195-197.
Boyd, A.E.W. (1949). Problems associated with potato. Ann. App.
Biol., 34:622-636.
Butler, E.J. (1918). Fungi and disease in plants. (E.J. Butler ed.)
PP:547. Calcutta and Simla, India.
Chan, J.Y.H. and Sackston, (1973). Non specificity of necrosis
inducing toxin of solerotiorum bataticola. Canadian Journal
of Botany, 51:690-692.
Chupp, C. and Chof, A.F. (1960). Vegetable diseases and their
control. Ronall Press, New York.
Dhingra, O.D. and Sinchair, J.B. (1977). An annotated bibliography
of M. phaseolina, 1905-1975. Universidads Federal de
Vicosa, Vicosa, MG, Brazil and University of Illinois, Urban,
IL, USA.
Dohroo N.P.; Sharma, S.L. (1984). Biological control of rhizome
rot of Ginger in storage with Trichoderma viride. Indian
Journal of Plant Pathology, 2:185-186.
Edmunds, L.K. (1964). Combined relation of plant maturity.
Temperature
and
soil
moisture
to
charcoal
stalk-rot
development in grain sorghum. Phytopathology, 54:514-517.
Ehteshamal, H.S. and Ghaffar, A. (1993). Use of Rhizobia in
control of root-rot disease of sunflower, okra, soybean and
mugbean. Journal of Phytopathology, 138(2):157-163.
Elad, Y.; Zviel, Y. and Chet, I. (1986). Biological control of
Macrophomina
phaseolina
(Tassi)
harzianum. Crop Protection, 65:288-292.
lxx
by
Trichoderma
Evelyn, S.H. (1951). Sorghum breeding in the Sudan. World Crops,
3:65-68.
Fawzia, A.M. (1987). Comparative studies on three isolates of M.
phaseolina (Tassi) Goid. on millet, sesame and potato. M.Sc
Thesis, University of Khartoum, Sudan.
Francl, L.J.; Wyllie, T.D. and Rosenbrock, M. (1988). Influence of
crop rotation on population density of M. phaseolina in soil
infested with Heterodera glycines. Plant Dis., 72:760-764.
Gray, S.P.; Bhushan, R. and Metha, R. (1983). A survey for
alkaloids in Rajastan desert plants. Trans. Indian Soc.
Desert Technol. Univ. Cont. Desert Stud. 5:62-64.
Goth,
R.W.
and
Ostazeski,
S.A.
(1965).
Sporulation
of
Macrophomina phaseolina on propylene oxid-sterilized leaf
tissues. Phytopathology, 55:1156.
Hagedron, D.J. (1991). Ashy stem blight in: R. Hall (ed.),
compendium
of
bean
disease.
PP:17-18.
American
Phytopathological Society, Minnesota, USA.
Hajra, K.K.; Khatua, D.C.; Mukherjee, N. (1992). Antagonistic
bacteria
against
fungal
pathogen.
Journal
of
Mycopathological Research, 30(1):65-70.
Hesse, G. and Reicheneder, F. (1936). African arrow poisons
calotropin. Ann. Chem., 526(1):252-276.
Hesse, G.; Ludwig, G. (1960). African arrow poisons vix
varuscharine, a second sulfur containing heart poison
Calotropis procera. Ann., 632:159-171.
Hussein, M. and Ahmed, G.A. (1960). Studies on the sporulation of
Macrophomina phaseolina (Maubl) Ashby, causing stem rot
disease on jute, with reference to the possible causes of
lxxi
outbreak of the disease in nature. Pak. J. Sci. Ind. Res.,
3(4):219.
Ilyas, M.B. and Sinclair, J.B. (1974). Effect of plant age upon the
development
in
soybean
infected
by
Macrophomina
phaseolina. Phytopathology, 64:156-157.
Jacobson, H. (1977). Isolation and identification of toxic agent
from plant, in host plant, in host plant resistance to pest.
Ace. Symp. Ser., 62:153-154.
Jones, P.S.; Ley, S.V.; Morgan, E.D. and Santafianas, D. (1989).
The chemistry of the neem tree, focus on phytochemicol
pesticides. The Neem Tree, Boca Raton vol. 1, ARC Press,
19-45.
Ketkar, C.M. (1976). Utilization of neem (Azadirachta indica A.
Juss.) and its products. Report of the Modified Neem Cake,
Manurial Project. P:234.
Ladd, T.L.; Jacobson, M. and Buriff, C.R. (1978). Japanese
beetles: Extracts from neem tree seed as feeding deterrents.
J. Econ. Ent., 71:810-813.
Ludwig, C.A. (1925). Plant diseases. South Carolina Agric. Expt.
Sta. Ann., 38:51-55.
Luttrell, E.S. and Garren, K.H. (1952). Blights of snap bean in
Georgia. Phytopathology, 42:607-613.
Mahmoud, M.A. (1977). An application for approval of release of
two varieties of grain sorghum. Proceedings of Sudan
National Variety Release Committee.
Maublance, A. (1905). Macrophomina phaseoli. Especes Novrelles
de Champignons inferieurs. Soc. Mycol. De France Bul.,
21:87-94.
lxxii
Mohamed, B.E.; El-Eraki, S. and El-Ginid, A.Y. (1991). Interaction
of Meldogyne incognita and M. phaseolina under different
pesticide treatments. Agricultural Research Review, 68:581587.
O’Brien, M.J. and Rich, A.E. (1976. Potato disease. US, Dept.
Agric. Handbook. PP:474.
Omer, A.D. (1986). Incidence of potato viruses, their effect on
potato production in the Sudan. M.Sc. Thesis, University of
Khartoum, Sudan.
Osman, E.I. and Mahmoud, M.A. (1992). Improved sorghum
genotypes suitable for irrigated and rainfed lands of Sudan.
Proceedings of Sudan National Variety Release Committee.
Park, M. (1933). Report on the work of the mycological division.
Ceylon Dept. Agric. Adm. Rpt. Dir. Agr. D116-D122.
Pawar, M.N.; More, B.B. and Utikar, P.Q. (1978a). Host range of M.
phaseoli (Maubl) Ashby inciting charcoal-rot of sunflower.
Food Farming and Agriculture, 10, 20.
Pushkarnath (1964). Potato in India. Indian Council of Agricultural
Research. New Delhi. Charcoal-rot (3) plant characters and
their range of variability. PP:55.
Pushkarnath (1976). Potato in Sub-Tropic Orient. Longman Ltd.
New Delhi. PP:289.
Quadrat, I.; Khuda, M. and Amir, S.M. (1969). Isolation and study
of a polysaccharide from Calotropis procera. Soc. Res.
(Dekka, Pakistan), 6:23-24.
Radwanski,
S.
(1977).
characteristics
and
Neem
Tree:
commercial,
distribution.
Livestock, 90:62-63; 65-66.
lxxiii
World
potential,
Crops
and
Reddy, G.R. (1991). Effect of certain seed-borne fungi on seed
germination of groundnut. Journal of Research, APNU,
19:77-78.
Reichert, I. and Hellinger, E. (1947). On the occurrence,
morphology
and
parasitism
of
Sclerotium
bataticola.
Palestine J. Bot. Rehovotser, 16:107-147.
Rod, J. (1984). Antagonistic effect of some fungi on fungal
pathogens causing storage rots of onion. Ceska Mykologie,
38:235-239.
Roger, L. (1953). Phytopathologie des pays Chauds. Vol. 1, Paris,
Paul Lecharalier.
Sahai, D.; Dutt, B.L. and Paharia, K.D. (1970). Reaction of some
wild
and
cultivated
potato
varieties
to
charcoal-rot.
American Potato Journal, 47:427-429.
Satti, A.A. (1997). Cucurbits insect pest complex, seasonal
abundance, host preference and control with emphasis on
botanical extracts. M.Sc. Thesis. University of Khartoum,
Sudan.
Schmuterer. H. (1995). The neem tree, source of unique natural
product for integrated pest management. Published by VCH
Germany.
Sharma, G.K. (1934). Calotropis procera. Ind. J. Vet. Sci., 4:63-74.
Seiber, I.N.; Nelson, C.J. and Lee, S.M. (1982). Cardendides in the
latex and leaves of seven asclepias species and Calotropis
procera. Phytochemistry, 21:2342-2348.
Semeniuk, G. (1944). Seedling infection of Dent maize by
Sclerotium bataticola Taub. Phytopathology, 34:838-843.
lxxiv
Siddig, S.A. (1987). An integrated pest management programme
including neem treatment for combating potato pest in the
Sudan. Proc. 2nd Int. Neem Conf. Nairobi, Kenya, 1988.
Siddig, S.A. (1993). An integrated pest management approach
including neem treatments for control of potato pests under
high
soil
conditions
in
Sudan.
Proc.
World
Neem
Conference. Bengator, India, 24-28 Dec.
Sinha, O.K. and Khare, M.N. (1977). Macrophomina phaseolina
(Tassi) (Coid). The root-rot causing pathogen is commonly
found in many seeds. Indian Phtopathology, 30:337-340.
Singh, R.S. and Chohan, J.S. (1972). Charcoal-rot of Ridge-gourd.
Apycnidial strain of M. phaseolina (Maulb) Ashby from India.
Indian Phytopathology, 25:463-464.
Singh, R.P. and Kataria, P.K. (1985). Toxicity of some plants
extract to mesquite larvae. Indian J. Int., 14:401-404.
Singh, S.K.; Nene, Y.L. and Reddy, M.V. (1990). Influence of
cropping systems on M. phaseolina population in the soil.
Plant Dis., 74:812-814.
Small, W. (1928). Further notes on Rhizoctonia bataticola (Taub.)
Butler. Trop. Agr. (Ceylon) 67:94-95.
Smith, R.S. (1964). Effect of diurnal temperature fluctuation on the
charcoal-rot disease of Pinus lambertiana. Phytopathology,
55:61-64.
Tarr, S.A.J. (1962). Inflorescence and grain disease. The
Commonwealth Mycological Institute. Kew, England, P. 196252.
Thakur, Ji. (1979). Chemical control of Macrophomina root-rot of
jute. Indian Phyopathology, 32:280-281.
lxxv
Thirumalachar, M.J. (1953). Pycnidial stage of charcoal-rot
inciting fungus with a discussion on its nomenclature.
Phytopathology, 43:608-610.
Thirumalachar, M.J. (1955). Incidence of charcoal-rot of potato in
Bihar
(India)
in
relation
to
cultural
conditions.
Phytopathology, 45:91-93.
Thirumalachar, M.J.; Neergaard, P. and Fakir, G. (1977). Methods
for pathogenicity test of seed-borne M. phaseolina isolated
from different hosts. Phytopathology, 88:234-237.
Tompkin, C.M. and Gardner, M.W. (1935). Relation of temperature
to infection of bean and cowpea seedling by Rhizoctonia
bataticola. Hilgardia, 9:219-230.
Turkensteen,
L.J.
and
Hooker,
W.J.
(1981).
Charoal-rot.
Compendium of Potato Disease, 56-57.
Watson, R.D. (1943). Charcoal-rot of potatoes. Phytopathology,
33:1120.
Young, P.A. (1949). Symptoms and resistance of crop plants to
charcoal-rot and Ashy stem blight. Phytopathology, 39:27.
Zaki, M.I. and Mgbool, M.A. (1993). Seed-borne fungi of bottle
gourd from Faisalabad and their control. Pakistan Journal of
Phytopathology, 4:54-57.
Zenab, A.E. (1997). Neem aqueous and organic extracts for the
control of powdery mildew on cucurbits. M.Sc. Thesis,
University of Khartoum, Sudan.
Zimmerman, G. (1985). Studies on biological control of Dutch Elm
disease with Trichoderma pellets. Nachrichtenblalt des
Deutschen pflan zen schutzsionstu, 37:113-117.
lxxvi
APPENDIX I
GENERAL
[1] Potato Dextrose Agar (PDA) Medium
*
Components
Pleeled sliced potatoes
200 g
*
Agar
15 g
*
Dextrose
20 g
*
Distilled water
100 g
Preparation
200 g pleeled potatoes were cut into small pieces, distilled
water added and heated for 20 minutes and then strained through
muslin. Dextrose and agar were then added to the extract, and the
volume made-up to one litre with distilled water. The prepared
medium was sterilized by autoclaving at 120°C for 20 minutes.
[2] Chemical Constituents of Neem
All parts of Azadirachta indica A. Juss. tree (i.e. bark, leaves,
fruits and seeds) have been examined by chemists. All of the well
characterized compounds identified in Neem tree belong to the
class
Triterpenoids
Azadirachtin
is
the
most
interesting
Triterponoid from Neem tree. Other active compounds contained
in the kernel are salannin, salannol, salannolacetate, 3-deactyl
salannin, 4-epoxyazaradion, nimbinen and deacetylnimbinen.
lxxvii
APPENDIX II
STATISTICAL ANALYSIS OF
VARIANCE
N.B: For all tables:
D.F
=
Degree of freedom
S.S
=
Sum of squares
M.S
=
Mean square
F
=
Variance ratio
*
=
Significant
**
=
Highly significant
n.s
=
Non-significant
Between
=
Treatments
Within
=
Error
lxxviii
APPENDIX II-A
Effect of the two isolates of M. phaseolina on the height
of sorghum plant (season 1999/2000)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
295.9
147.96
6.07*
Error
9
219.5
24.39
Total
11
515.4
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
376.0
188.01
3.04n.s
Error
9
556.3
61.81
Total
11
932.3
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
103.9
51.97
0.90n.s
Error
9
521.8
57.98
Total
11
625.7
lxxix
APPENDIX II-B
Effect of the two isolates of M. phaseolina on the height
of sorghum plant (season 2000/2001)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
370.9
185.45
10.35*
Error
9
161.6
17.96
Total
11
532.5
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
408.7
204.33
2.45n.s
Error
9
750.5
83.39
Total
11
1159.2
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
184.7
92.33
1.60n.s
Error
9
518.0
57.56
Total
11
702.7
lxxx
APPENDIX II-C
Effect of the two isolates of M. phaseolina on the height
of sorghum plant (season 1999/2000)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
571.0
285.5
41.25**
Error
9
62.3
6.92
Total
11
633.3
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
889.7
444.85
10.24**
Error
9
391.0
43.44
Total
11
1280.7
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
485.2
262.62
5.64*
Error
9
387.5
43.06
Total
11
872.7
lxxxi
APPENDIX II-D
Effect of the two isolates of M. phaseolina on the height
of sorghum plant (season 2000/2001)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
738.6
369.28
24.71**
Error
9
134.5
14.95
Total
11
873.1
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
1203.9
601.94
17.89**
Error
9
302.8
33.64
Total
11
1506.7
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
753.2
376.58
18.73**
Error
9
180.9
20.10
Total
11
934.1
lxxxii
APPENDIX II-E
Effect of the two isolates of M. phaseolina on the height
of potato plant (season 1999/2000)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
279.4
139.7
20.04**
Error
9
62.7
6.97
Total
11
342.1
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
414.5
207.25
16.61**
Error
9
112.3
12.48
Total
11
526.8
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
581.3
290.66
20.98**
Error
9
127.7
13.86
Total
11
706.0
lxxxiii
APPENDIX II-F
Effect of the two isolates of M. phaseolina on the height
of potato plant (season 2000/2001)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
211.7
105.83
29.45**
Error
9
32.3
3.59
Total
11
244.0
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
578.8
289.39
67.10**
Error
9
38.8
4.31
Total
11
617.6
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
103.9
51.97
0.90n.s
Error
9
521.8
57.98
Total
11
625.7
lxxxiv
APPENDIX II-G
Effect of the two isolates of M. phaseolina on the height
of potato plant (season 1999/2000)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
296.0
147.99
59.67**
Error
9
22.3
2.48
Total
11
318.3
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
189.3
94.65
22.61**
Error
9
37.7
4.19
Total
11
227.0
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
380.4
190.18
28.31**
Error
9
60.5
6.72
Total
11
451.1
lxxxv
APPENDIX II-H
Effect of the two isolates of M. phaseolina on the height
of potato plant (season 2000/2001)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
2
231.4
115.7
43.31**
Error
9
24.0
2.67
Total
11
255.4
60 days
Source of variation
D.F
S.S
M.S
F
Between
2
568.3
284.16
166.39**
Error
9
15.4
1.71
Total
11
583.7
90 days
Source of variation
D.F
S.S
M.S
F
Between
2
693.1
346.53
141.54**
Error
9
22.0
2.45
Total
11
715.1
lxxxvi
APPENDIX II-I
Effect of the two isolates of M. phaseolina on the root
length of sorghum and potato plants (season 1999/2000)
ANOVA TABLE:
Sorghum
Source of variation
D.F
S.S
M.S
F
Between
2
49.9
24.96
45.11**
Error
9
5.0
0.55
Total
11
54.9
Potato
Source of variation
D.F
S.S
M.S
F
Between
2
60.1
30.01
47.94**
Error
9
5.6
0.63
Total
11
65.7
lxxxvii
APPENDIX II-J
Effect of the two isolates of M. phaseolina on the root
length of sorghum and potato plants (season 2000/2001)
ANOVA TABLE:
Sorghum
Source of variation
D.F
S.S
M.S
F
Between
2
32.8
16.42
17.34**
Error
9
8.5
0.95
Total
11
41.3
Potato
Source of variation
D.F
S.S
M.S
F
Between
2
45.8
22.90
39.79**
Error
9
5.2
0.58
Total
11
51.0
lxxxviii
APPENDIX II-K
Effect of the two isolates of M. phaseolina on the root
length of sorghum and potato plants (season 1999/2000)
ANOVA TABLE:
Sorghum
Source of variation
D.F
S.S
M.S
F
Between
2
28.1
14.04
22.81**
Error
9
5.5
0.64
Total
11
33.6
Potato
Source of variation
D.F
S.S
M.S
F
Between
2
41.4
20.69
32.17**
Error
9
5.8
0.64
Total
11
47.2
lxxxix
APPENDIX II-L
Effect of the two isolates of M. phaseolina on the root
length of sorghum and potato plants (season 2000/2001)
ANOVA TABLE:
Sorghum
Source of variation
D.F
S.S
M.S
F
Between
2
21.9
10.94
8.55*
Error
9
11.5
1.28
Total
11
33.4
Potato
Source of variation
D.F
S.S
M.S
F
Between
2
67.3
33.66
75.93**
Error
9
4.0
0.44
Total
11
71.3
xc
APPENDIX II-M
Pathogenicity of M. phaseolina isolates tested in tubers
of cv. Alpha
ANOVA TABLE:
7 days
Source of variation
D.F
S.S
M.S
F
Between
2
140.8
70.40
82.53**
Error
9
7.7
0.85
Total
11
148.5
14 days
Source of variation
D.F
S.S
M.S
F
Between
2
471.4
235.7
132.63**
Error
9
16.0
1.78
Total
11
487.4
21 days
Source of variation
D.F
S.S
M.S
F
Between
2
960.0
480.01
71.67**
Error
9
60.3
6.71
Total
11
1020.3
xci
APPENDIX II-N
Effect of the neem seeds powder against M. phaseolina
on the height of potato plants (season 2000/2001)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
5
244.56
48.91
23.003**
Error
18
38.28
2.13
Total
23
282.84
45 days
Source of variation
D.F
S.S
M.S
F
Between
5
279.0
55.80
6.04*
Error
18
166.0
9.22
Total
23
495.0
60 days
Source of variation
D.F
S.S
M.S
F
Between
5
359.72
71.94
8.78*
Error
18
147.42
8.19
Total
23
507.14
xcii
APPENDIX II-O
Effect of the neem seeds powder against M. phaseolina
on the height of potato plants (season 2001/2002)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
5
283.26
56.65
11.19**
Error
18
91.15
5.06
Total
23
374.41
45 days
Source of variation
D.F
S.S
M.S
F
Between
5
261.7
52.34
19.68**
Error
18
47.88
2.66
Total
23
309.58
60 days
Source of variation
D.F
S.S
M.S
F
Between
5
315.94
63.19
20.34**
Error
18
55.91
3.11
Total
23
371.85
xciii
APPENDIX II-P
Effect of the Usher leaves powder against M. phaseolina
on the height of potato plants (season 2000/2001)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
5
356.36
71.27
32.44**
Error
18
39.55
2.20
Total
23
395.91
45 days
Source of variation
D.F
S.S
M.S
F
Between
5
515.81
103.16
8.28*
Error
18
224.23
12.46
Total
23
740.04
60 days
Source of variation
D.F
S.S
M.S
F
Between
5
586.2
117.24
9.96*
Error
18
211.79
11.77
Total
23
797.99
xciv
APPENDIX II-Q
Effect of the Usher leaves powder against M. phaseolina
on the height of potato plants (season 2001/2002)
ANOVA TABLE:
30 days
Source of variation
D.F
S.S
M.S
F
Between
5
413.53
82.71
11.82**
Error
18
125.98
6.998
Total
23
539.51
45 days
Source of variation
D.F
S.S
M.S
F
Between
5
535.77
107.15
13.21**
Error
18
146.03
8.11
Total
23
681.80
60 days
Source of variation
D.F
S.S
M.S
F
Between
5
527.08
105.42
5.91*
Error
18
320.86
17.83
Total
23
847.94
xcv
APPENDIX II-R
Effect of the Neem seeds powder against M. phaseolina
on the fresh and dry weights of potato plants
ANOVA TABLE:
Dry weight
Source of variation
D.F
S.S
M.S
F
Between
5
1.55
0.31
2.12n.s
Error
18
2.64
0.15
Total
23
4.19
Fresh weight
Source of variation
D.F
S.S
M.S
F
Between
5
54.62
10.92
30.47**
Error
18
6.45
0.36
Total
23
61.07
xcvi
APPENDIX II-S
Effect of the Usher leaves powder against M. phaseolina
on the fresh and dry weights of potato plants
ANOVA TABLE:
Dry weight
Source of variation
D.F
S.S
M.S
F
Between
5
4.19
0.84
4.16*
Error
18
3.62
0.20
Total
23
7.81
Fresh weight
Source of variation
D.F
S.S
M.S
F
Between
5
68.47
13.68
27.74**
Error
18
8.88
0.49
Total
23
77.30
xcvii
APPENDIX II-T
Effect of the Neem seeds powder against M. phaseolina
on the final tuber yield of potato plants
ANOVA TABLE:
Season 2000/2001
Source of variation
D.F
S.S
M.S
F
Between
5
360.64
72.13
90.75**
Error
18
14.31
0.79
Total
23
374.95
Season 2001/2002
Source of variation
D.F
S.S
M.S
F
Between
5
216.50
43.30
116.49**
Error
18
6.69
0.37
Total
23
223.19
xcviii
APPENDIX II-U
Effect of the Usher leaves powder against M. phaseolina
on the final tuber yield of potato plants
ANOVA TABLE:
Season 2000/2001
Source of variation
D.F
S.S
M.S
F
Between
5
191.45
38.29
30.73**
Error
18
22.43
1.25
Total
23
213.88
Season 2001/2002
Source of variation
D.F
S.S
M.S
F
Between
5
204.07
40.81
42.74**
Error
18
17.19
0.95
Total
23
221.26
xcix
‫ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ‬
‫ﺧﻼﺻﺔ اﻷﻃﺮوﺣﺔ‬
‫دراﺳﺔ ﺗﺄﺛﻴﺮ ﻣﺴﺤﻮق ﺑﺬور اﻟﻨﻴﻢ وﻣﺴﺤﻮق أوراق اﻟﻌﺸﺮ ﻋﻠﻰ‬
‫ﻓﻄﺮ ‪ Macrophomina phaseolina‬اﻟﻤﺴﺒﺐ ﻟﻤﺮض اﻟﺘﻔﺤﻢ ﻓﻰ‬
‫اﻟﺬرة واﻟﺒﻄﺎﻃﺲ‬
‫ﻣﻦ اﻟﻤﻌﺮوف ﻋﻦ ﻓﻄﺮ‬
‫‪M. phaseolina‬‬
‫أﻧﻪ ﻳﺴﺒﺐ أﺿﺮارًا ﺑﺎﻟﻐ ًﺔ‬
‫ﻋﻠﻰ اﻟﻌﺪﻳﺪ ﻣﻦ اﻟﻤﺤﺎﺻﻴﻞ اﻟﻬﺎﻣﺔ ﻣﺜﻞ اﻟﻘﻄﻦ‪ ،‬اﻟﺬرة‪ ،‬اﻟﺒﻄﺎﻃﺲ‪،‬‬
‫اﻟﺴﻤﺴﻢ واﻟﺪﺧﻦ ﻣﻤﺎ ﻳﺆدى إﻟﻰ ﻋﺪم إﻧﺒﺎت اﻟﺒﺬور أو ﺗﻌﻔﻦ اﻟﺒﺎدرات‬
‫اﻟﻄﺮى أو ﺗﻘﺮح اﻟﺴﻴﻘﺎن اﻟﺬى ﻳﺆدى ﺑﺪورﻩ إﻟﻰ ﺧﺴﺎﺋﺮ آﺒﻴﺮة ﻓﻰ‬
‫اﻟﻤﺤﺼﻮل‪ .‬ﻓﻰ اﻟﺴﻮدان ﺗﻤﺖ اﻹﺷﺎرة إﻟﻰ اﻷﺿﺮار اﻟﻜﺒﻴﺮة اﻟﺘﻰ‬
‫ﻳﺴﺒﺒﻬﺎ هﺬا اﻟﻔﻄﺮ ﻋﻠﻰ ﻣﺤﺼﻮﻟﻰ اﻟﻘﻄﻦ واﻟﺬرة ﺑﻮاﺳﻄﺔ اﻟﻌﺎﻟﻢ‬
‫ﻋﺎﻣﻰ‬
‫‪1956‬‬
‫و‪1962‬م‪.‬‬
‫ﺗﻬﺪف هﺬﻩ اﻟﺪراﺳﺔ إﻟﻰ ﻋﺰل اﻟﻔﻄﺮ‬
‫ﻣﺤﺼﻮﻟﻰ‬
‫‪Tarr‬‬
‫اﻟﺬرة‬
‫واﻟﺒﻄﺎﻃﺲ‬
‫وإﺧﺘﺒﺎر‬
‫اﻟﻘﺪرة‬
‫‪M. phaseolina‬‬
‫اﻹﻣﺮاﺿﻴﺔ‬
‫ﻟﻪ‬
‫ﻣﻦ‬
‫ﻋﻠﻰ‬
‫اﻟﻤﺤﺼﻮﻟﻴﻦ‪ ،‬وآﺬﻟﻚ دراﺳﺔ ﺗﺄﺛﻴﺮ ﻣﺴﺤﻮق ﺑﺬور اﻟﻨﻴﻢ وﻣﺴﺤﻮق أوراق‬
‫اﻟﻌﺸﺮ ﻋﻠﻰ اﻟﻔﻄﺮ‬
‫‪M. phaseolina‬‬
‫وذﻟﻚ ﺑﻐﺮض إﺳﺘﻌﻤﺎل اﻟﻤﺴﺘﺨﻠﺼﺎت‬
‫اﻟﻄﺒﻴﻌﻴﺔ ﻓﻰ ﻣﻜﺎﻓﺤﺔ اﻵﻓﺎت ﻧﺴﺒ ًﺔ ﻟﻤﺎ ﺗﺴﺒﺒﻪ اﻟﻤﻮاد اﻟﻜﻴﻤﻴﺎﺋﻴﺔ‪-‬‬
‫اﻟﻤﺴﺘﻌﻤﻠﺔ ﺣﺎﻟﻴ ًﺎ ﻓﻰ اﻟﻤﻜﺎﻓﺤﺔ‪-‬ﻣﻦ أﺿﺮا ٍر ﺑﺎﻟﻐ ٍﺔ ﺑﺎﻹﻧﺴﺎن واﻟﺤﻴﻮان‬
‫واﻟﺘﺮﺑﺔ واﻟﺒﻴﺌﺔ ﻋﻤﻮﻣ ًﺎ‪.‬‬
‫ﻓﻰ ﺗﺠﺎرب اﻟﻘﺪرة اﻹﻣﺮاﺿﻴﺔ ﻟﻠﻔﻄﺮ‬
‫‪M. phaseolina‬‬
‫وﺟﺪ أن‬
‫اﻟﻌﺰﻟﺘﻴﻦ اﻟﻤﺄﺧﻮذﺗﻴﻦ ﻣﻦ اﻟﺬرة واﻟﺒﻄﺎﻃﺲ ﻟﻬﻤﺎ ﻧﻔﺲ اﻟﻘﺪرة ﻋﻠﻰ‬
‫إﺣﺪاث اﻟﻤﺮض ﻋﻠﻰ أى ﻣﻦ اﻟﻤﺤﺼﻮﻟﻴﻦ وﻇﻬﻮر ﻧﻔﺲ اﻷﻋﺮاض‬
‫‪c‬‬
‫واﻟﺘﻰ ﺗﺘﻤﺜﻞ ﻓﻰ ﺗﻌﻔﻦ اﻟﺒﺎدرات اﻟﻄﺮى وﺗﻘﺮح اﻟﺴﺎق وﺗﻘﺰم اﻟﻨﺒﺎت‪،‬‬
‫أﻣﺎ اﻟﺠﺬور ﻓﺘﺘﺤﻮل إﻟﻰ اﻟﻠﻮن اﻟﺒﻨﻰ اﻟﺪاآﻦ ﺛﻢ ﻳﺴﻮد ﻓﻰ اﻟﻤﺮاﺣﻞ‬
‫اﻟﻤﺘﻘﺪﻣﺔ ﻣﻦ اﻹﺻﺎﺑﺔ‪ .‬وﻓﻰ ﺣﺎﻟﺔ إﺷﺘﺪاد اﻹﺻﺎﺑﺔ ﺗﺠﻒ اﻟﻨﺒﺎﺗﺎت‬
‫وﺗﺮﺗﻔﻊ ﻧﺴﺒﺔ اﻟﻤﻮت ﻓﻴﻬﺎ‪.‬‬
‫وﻟﻘﺪ أﻇﻬﺮت اﻟﺪراﺳﺔ ﻓﻌﺎﻟﻴﺔ ﻣﺴﺤﻮق ﺑﺬور اﻟﻨﻴﻢ ﻓﻰ ﺗﻘﻠﻴﻞ ﻧﺴﺒﺔ‬
‫اﻹﺻﺎﺑﺔ ﺑﺎﻟﻤﺮض ﺑﺪرﺟ ٍﺔ ﺗﻤﺎﺛﻞ ﻧﺘﺎﺋﺞ ﻣﻌﺎﻣﻠﺔ اﻟﻘﻴﺎس )‪ ،(Control‬ﺑﻴﻨﻤﺎ‬
‫آﺎن ﻣﺴﺤﻮق أوراق اﻟﻌﺸﺮ أﻗﻞ ﺗﺄﺛﻴﺮًا ﻓﻰ اﻟﺘﻘﻠﻴﻞ ﻣﻦ ﻧﺴﺒﺔ اﻹﺻﺎﺑﺔ‬
‫ﺑﺎﻟﻤﺮض‪ .‬آﻤﺎ أﻇﻬﺮت اﻟﺪراﺳﺔ زﻳﺎد ًة ﻓﻰ إﻧﺘﺎج ﻣﺤﺼﻮل اﻟﺒﻄﺎﻃﺲ ﻋﻨﺪ‬
‫إﺳﺘﻌﻤﺎل ﻣﺴﺤﻮق ﺑﺬور اﻟﻨﻴﻢ ﻓﻰ ﻣﻜﺎﻓﺤﺔ اﻟﻔﻄﺮ ‪ ،M. phaseolina‬وﻗﺪ‬
‫أﺷﺎر ﻟﺬﻟﻚ اﻟﺪآﺘﻮر ﺻﺪﻳﻖ )‪ (1987‬ﻓﻰ دراﺳ ٍﺔ ﻋﻦ ﻣﻜﺎﻓﺤﺔ ﺁﻓﺎت‬
‫اﻟﺒﻄﺎﻃﺲ ﻓﻰ اﻟﺴﻮدان ﺑﻤﺴﺘﺨﻠﺼﺎت ﻧﺒﺎت اﻟﻨﻴﻢ‪.‬‬
‫أﻇﻬﺮت هﺬﻩ اﻟﺪراﺳﺔ اﻟﺤﺎﺟﺔ اﻟﻤﺎﺳﺔ ﻟﻠﻤﺰﻳﺪ ﻣﻦ اﻟﺪراﺳﺎت‬
‫ﻟﻠﻨﺒﺎﺗﺎت اﻟﻄﺒﻴﻌﻴﺔ وﻣﺴﺘﺨﻠﺼﺎﺗﻬﺎ ﻓﻰ ﻣﻜﺎﻓﺤﺔ اﻵﻓﺎت اﻟﺘﻰ ﺗﺼﻴﺐ‬
‫اﻟﻤﺤﺎﺻﻴﻞ اﻟﻬﺎﻣﺔ وذﻟﻚ ﻟﻠﺘﻘﻠﻴﻞ أو اﻟﺘﺨﻠﺺ ﻧﻬﺎﺋﻴ ًﺎ ﻣﻦ إﺳﺘﻌﻤﺎل‬
‫اﻟﻤﺒﻴﺪات اﻟﻜﻴﻤﻴﺎﺋﻴﺔ اﻟﺘﻰ ﺛﺒﺖ أن ﻟﻬﺎ أﺿﺮارًا آﺒﻴﺮ ًة ﻋﻠﻰ اﻹﻧﺴﺎن‬
‫واﻟﺤﻴﻮان واﻟﺘﺮﺑﺔ واﻟﺒﻴﺌﺔ‪.‬‬
‫‪ci‬‬