Medicinal plants are
considered as rich resources of ingredients which can be used in drug
development. Apart from medicinal uses,
they are also used in natural dye, pest control, food, perfumes, and tea and so
on. It also reduces such as diarrhea, constipation, hypertension, low sperm
count, dysentery, piles, coated tongue, menstrual disorders, bronchial asthma
etc. Most of the medicinal plants get diseased because of this, there is an
economic loss caused as well as it also affects the diversity of rare,
endangered, endemic, native, vulnerable plant species.
Medicinal plants have long played
important roles in the treatment of diseases all over the world. Medicinal
plants are a source for a wide variety of natural antioxidants and are used for
the treatment of diseases throughout the world. Some of these properties are
antimicrobial, anticancer, antidiabetic, antiantherosclerosis, immunomodulatory
and even renoprotection or hepatoprotective effects.
Most of the medicinal plants have specific compounds other than
antioxidants, which are effective in the treatment or prevention of diseases.
In this regard medicinal plants have also been a reliable source of preparation
of new drugs. The herbal products today
symbolize safety in contrast to the synthetics that are regarded as unsafe to
human and environment. There are 2, 50,000 higher plant species on earth, more
than 80,000 are medicinal. India is one of the word’s 12 biodiversity centres
with the presence of over 45,000 different plant species. In
India, drugs of herbal origin have been used in traditional systems of
medicines such as Unani and Ayurveda, since ancient times. The drugs are derived either from the whole
plant or from different organs, like leaves, stem, bark, root, flower, seed
etc. Some drugs are prepared from excretory plant
products such as gum, resin, and latex. Even
the Allopathic system of medicine has adopted a number of plant derived drugs.
Some important chemical intermediates needed for manufacturing the modern drugs
are also obtained from plants.
India
is floristically rich and ranking 10th among the plant resources
rich nations of the world and 4th among the countries of Asia. India is the 7th
largest country in the world and Asia’s 2nd largest nation with an area of
3,287,263 Sq.Km. and is an example of diverse ecosystems. Damping-off disease is caused by a soil-borne
fungus Rhizoctonia solani that attacks germinated seedlings that have
not yet emerged or have just emerged.
Damping-off of seedling is very common all over the world. It occurs in agriculture and forest soils, in
tropical and temperate climates and in almost every greenhouse or nursery. Damping-off can be of two types, that is,
pre-emergence damping-off in which the seeds and radical rot before the
seedlings emerge from the soil and the post -emergence damping-off in which the newly emerged seedlings are
killed at ground level after they emerge from the soil, causing them to
collapse. This is a common symptom of
post- emergence damping-off.
Medicinal plants are also
suffered fungal diseases like any other food and fodder crops but are not given
that much of importance likes other commercially important crops. Medicinal plants also causes diseases such as
damping-off seedling, seedling blight, root rot, stem rot, leaf spot diseases
etc. There are various types of fungal
diseases of herbal medicinal plants viz. Phytophthora stem blight and
root rot. Aerial stem blight and root rot are caused by Phytophthora
nicotianae and occasionally other species.
Pythium root rot, this pathogen doesn’t cause branch blight, only root
rot and damping-off of seedlings. Rhizoctonia
stem and root rot, Rhizoctonia species sometimes causes stem rot
turn yellow, wilt and collapse. Affected
plants are stunted; their roots have brown lesions, leaves turns yellow and
plants wilt even when soil moisture is sufficient. Gray-mold Botrytis Blight, this disease
caused by Botrytis cineria is seen occasionally during cool, moist
spring weather. The pathogen usually
builds-up on dead plant parts and disease develops when these come into contact
with living tissue. Symptoms progress
rapidly and can include leaf spots and blights, stem cankers, stem rots and
damping-off of seedlings. Black root
rot, is caused by the fungus Thielaviopsis basicola. The major root problems in Asparagus
include Fusarium crown and root rot and Phytophthora rot. Damping-off disease is caused by soil-borne
fungus Rhizoctonia solani that attacks germinated seedlings that have
not yet emerged or have just emerged.
Fennel crop suffer from many diseases causing by fungi pathogens, such
as Rhizoctonia solani, Pythium aphanidermatum, Cercospora
sp., Sclerotinia sclerotiorum, Alternaria alternate and Fusarium
oxysporum.
There are various
medicinal plants occurred such as Adhatoda zeylanica, Aegle marmelos, Areca catechu, Azadirachta indica,
Asparagus racemosus, Withania somnifera, Bidens pilosa, Butea monosperma, Calotropis
gigantea, Canna indica, Cassia tora, Cleom viscosa, Emblica officinalis, Saraca
asoca, Phyllanthous amarus(Bhumi Amla), Bacopa monnieri (Brahmi), Swirtia
chiraita(Chiraita), Gymnema sylvestre (Gudmar), Commiphora
wightii (Guggul), Tinospora cordifolia(Gulvel), Gloriosa superb(Calihari),
Andrographis paniculata (Kalmegh, Bhui neem), Solanum nigrum (Makoi),
Rauvolfia serpentina ( Sarpagandha), Casia augstifolia (Senna),
Ocimum sanctum (Tulsi), Mentha piperita(Peppermint) Lawsonia
innermis ( Henna, Mehndi), Aloe vera(Korphad), Catharanthus
roseus (Periwinkle,Sadafuli), Plumbago zeylanica (Swet Chitrak), Strychinos
nuxvomica (Kochila), Terminalia chebula (Hirda), Terminalia
bellerica (Behda), Tribulus terrestris (Gokhru), Macuna pruriens (
Khajkuhili) etc.
Most of the medicinal plants dies because of disease
attack. There are many reasons to cause
diseases viz- air-borne fungi, weather change, soil-borne fungi etc. Very few
information is available about the incidence, prevalence, epidemiology, and
management of medicinal plants diseases.
There is little information or research work is available on diseases of
medicinal plants. The amount of damage the disease causes to
plant is depends on the fungus, host tolerance/susceptibility, soil moisture
and temperature. Seedlings may die
before or after they emerge from the soil (pre-emergence and post-emergence
damping-off respectively). Seedlings in
seedbeds often are completely destroyed by damping-off or they die after
transplanting. Hence, try to investigate
ecofriendly management practices hence it will reduces the hazardous effects
causes by the environmentally harmful management practices. In that uses of Biorational pesticides; these
pesticides are defined as products that are considered to be environmentally
friendly because they have minimal harmful effects on non-target organisms and
the environment; they are frequently more “user friendly” than traditional
pesticides (Biochemicals which include plant products such as essential oils
and various compounds synthesized by other organisms such as chitin and
chitosan). Indeed, these biopesticides
present many advantages in term of sustainability, mode of action and toxicity
compared to chemical pesticides. By
using antagonism or biological pesticides it is also called as antibiosis-these
pesticides are living agents that are also called biological control
agents. For example, by using certain
bacteria, fungi it can be controlled ecofriendly. But including these things there are certain
drawbacks of biocontroling agent, is that, they are having certain limitations
means they resist the growth of pathogen at the certain level while
biocontroling agents are affected by environmental changes but on the other
hand chemical fungicides does not affected by environmental changes hence, try
to uses of chemical fungicides that causes minimal effect on host and its
residual affects does not persist for long period. Majority of herbal medicinal plants dies due
to disease attack and it losses generally on the nursery bed whenever economic
losses takes place because the whole plant get destroyed . Hence, to overcome this problem after
transplantations and avoid the economic losses.