Characteristics of pet/virus , plant disease , pest life cycle, regarding and repeating plant disease , selecting treatment methods, Control plant pest / virus .

1. Plant pests and virus
disease
By
Sneha sahu
Msc. 2nd semester
Sant gahira guru University ambikapur chhattisgarh
India

2. Contant
• Introduction
• Definition
• History
• characteristics of pest including virus
. Plant disease and disorder
. Plant pest
. Life cycle of pest
. Recording and repeating plant disease
. Selecting treatment methods
• pest transmission in plant
• control plant pest virus
• list of pest disease.
• Reference

3. Introduction
Pests are unwanted organisms that are a nuisance to
man or domestic animals and can cause injury to
humans , animals , plants , and property . Pests
reduce yield and / or quality in plants ranging from
field crops , fruits , and vegetables , to lawns , trees ,
and golf courses.

4. History
Ivanosk reported in 1892 that extract from infected
leaves were still infectious after filtration through a
Chamberland filtration leaf and he saw their virus in
tobacco called tobacco mosaic virus.
A pests is harmful for plant until the 1940s ,
Chemicals derived from plant And inorganic
composed were the source of pest central.

5. Definition
• Any organism that is detrimental to humans destroys
crops & structures poses threats to human health
and livestock reduces aesthetic and recreational
value.
• Pests include insects , mites , plant pathogens ,
weeds , mollusks , fish , birds and mammals.

6. Characteristics of pest including virus
• Viruses are obligate intrucellular parasites they require a lving cell
ar organiam for ita mutipication It can infet all living forms
induding plants, animals, bacteria et – Viruses can be observed
only under the electran miaroscope
• They am 10 to 100 times malier than bacteria and ita size ranges
hom 20 to 300 nm un thene vinusen can pass aanily thrmugh
bacteriological tites They are fiterable. Size of viruses is mnanure
with the help utratitration, utrucentritugaton anid electron
moRcopy
• Viruses do not have any kind of celular organization –it contans
either DNA or RNA an a nuclear matenat

7. Conti….
• M we know vruses aru an obigate intracelular paraaite and lach
the euuential enzyme tor protein and nucleic acid synthesin.
These viruties depend hast cell for ita repication and
mitipleation
• Vinunes ae unattected by antibictics, therm are many
diterences between micro-organism arid viruees in spite of that
vinases are considersd an micro organism especialy I the feld of
medical microtiology
• Virunes are of great concern in me feld of medical miurobiology
we espensble tfor various human disenses

8. Conti….
• ExamplesVrunes may be enveloped or non eveloped. Envelop is
made up ot hpoproteins and denved from host cel membrane -
Vrses reguire a lving media lke tive enbryoni ega, cell cute or
bacterial cells
• There am two lypes of viruas that arn DNA viruses d RNA
vinunes
• Vrunes may be enveloped or non eveloped. Envelop is made up
ot hpoproteins and denved from host cel membrane – Vrses
reguire a lving media lke tive enbryoni ega, cell cute or bacterial
cells
• There am two lypes of viruas that arn DNA viruses d RNA
vinunes

9. Plant disease and disorder
• Crops need to be protected from loss or
damage from pests and diseases. It is
important to corectly identify the pest,
disease or disorder so that the probiem
can be effectivelytreated Common plant
pests
• Mites
• Scale
• Aphids
• Moths

10. Continue
• Others – including mealybug,
frut ty, weevil, locust micro-
organisms that can cause
disease and these can
classified into 4 groups
• Fungi
• Bacteria
• Viruses
• nematodes

11. Plant pest
• Mites
Belong ta the spider family and live in a wide range of habitats
• Scale
Most scale insects are parasitos of plants, feeding on sap drawn drectly
plant’s vascular system.Adult temale scales are almost always immoble and
permanentty attached to the plant they have parasifised. They secrete a
waxy coating for defence and it is this waxy covecing that makes them quite
resistant to pesticides.
•Aphids
Aphids are small plant-feeding insects. Lke scale, some species of ants farm
aphids, protecting them on the plant they eat, and eating the horeydew that
the aphids release from anus
• Moths
Moths, and their caterpilars, are a major agricultural pest in many parts of
the world

12. Plant disease and disorder
Fungi disease
Fungi are simple plant-like bodies, which do not produce their own food,
and therefore live parasiticallyon living plarts, or saprophytically on dead
rotting material. Examples of fungal diseases attackingthe green tissue of
planta, Le. Leaves and unripe fruit include Powdery mildew, Downy
midew, Black spot, Botrytis and Stripe, Stam and Leaf Rust. Examples of
fungal diseases attacking roots and woody stems include, crown and root
rots, damping off diseases, fusarium root rot, Verticillum wilt or Black
heart and rhizoctonia root rot.
Bacteria
Bacteria are microscopic in size cells with simple nucious and no
chlorophyll. As plart diseases not as important as tungi. Bacteria also play
an important part in the breaking down of plant material and the fixation
of nitrogen from the atmosphere.

13. Conti…
Viruses
These organisms are not celular, but are ribonucieic acid (RNA) particies which can
multiply only within iving cells, by distracting the cells trom their normal function to
produce more virus infected cells, and to produce substancesrequired by the virus
Viruses are usually spread by vectors, such as insects. Infected pollen is another
method hereby viruses can spread.
Nematodes
Nematodes are long eei-like organismis ranging in length from 05 to 3.0mm. They
move through soil via the moisture fims between and around the soil particles. All
nematodes spend time in the soil but some also attack the stems and leaves. They
enter the leaves via the stomata.The disease damage caused by nematodes is a
result of the saliva secreted while the organism feeds. The above ground symptoms
of nematodes are not specific, plants simply lack vigour. Field diagnosis of
nematode damage is based on digging up plant roots and inspecting the nature of
damage. Root knot nematode results in small bead or gall style swelings on the
roots. Lesion nematode results in apen wounds on the root system.

14. Life cycle of plant pest
• To put it plainly, a pest’s life cycle is the time it takes for an egg to grow,
mature, and produce new eggs. Most insects follow three definite stages in
their life cycle: Growth, Maturation, and Reproduction.
Growth
Once an egg is laid, it goes through a growth stage. Pests that have a shorter
life expectancy typically experience rapid growth from egg to reproducing
organism. Mice are a good example of this. Some insect populations have
multiple, distinct intervals within the growth stage, such as Black Widow
spiders. Black widows go through a nymph stage after hatching, prior to
becoming a juvenile, and then finally a fully mature adult. During the growth
stage, pests are at their most vulnerable to predators, but can be more
difficult to target for pest control.

15. Conti….
MATURATION
After initial growth, many insects will experience a juvenile stage. This can be a rapid
process of only a couple of weeks to a 2-3 month period. These sub-adults may have
some of the features of adults of their species, but typically they look physically
different (whether it be size or coloring) and most importantly they lack sexual
maturity. External factors, such as a drought (like we are experiencing from Newcastle
to El Dorado Hills) can also speed up the process. You may have noticed this summer
that there are an awful lot of spiders hanging around.
REPRODUCTION
The successfulcompletion of a pest’s life cycle ends in their full maturity and the
production of offspring. Many pests reach the end of their life cycle when they
reproduce. Some pests will produce multiple generations of offspring over several
years, such as the Wolf spider, increasing their bloodline’s chances of survival. This is all
the more reason to control your local pest population as they can and will grow
exponentially. Understanding the pest life cycle is critical to effective pest control. At
Pro Active Pest Control, we are very familiar with pests local to Sacramento, Roseville,
and EI Dorado Hills. Our knowledge of ea individual pest’s life cycle is how we

16. Continue
Can effectively
treat pest
problems around
your home and
business. Contact
Pro Active Pest
Control today for
helping
controlling your
pests’ life cycles.

17. Regarding and repeating plant disease
• comprehensive report will include:
• Geographic location (Le. mapped site)
• Photographs of the problem, either the observed pest, or the observed
symptom
•A sample placed in a sealed jar or bag
• Plant affected
• Growth stage of the affected plant
• Approximate number of affected plants and the size of the area affected
• Possible source of introduction
• The date and time of the observation of the problem It is preferable to use
as many of these methods as necessary to make sure you can find it again

18. Selecting treatment methods
• Agricultural methods of controlling pests, diseases and disorders include:
• Quarantine
• use of disease free or resistant(or tolerant) planting material
• cultural - for example sanitation and disposing of crop residues
• soil sterilisation
• crop rotation
• provision of alternative hosts
• avoidance or amelioration of unfavourable conditions, for exampie careful
timing of weed, soil and water management operations
• chemical agents such as protectants and eradicants

19. Conti..
• Horticultural methods of controlling pests, diseases and disorders indude:
• Quarantine
• use of disease free or resistant (or tolerant) planting material
• cultural - for example sanitation, the establishmentand maintenance of
standards of hygiene such removing diseased roots, limbs or whole plants; cleaning
pruning and budding and grafting equipment; disposing of crop residues
• soil sterilisation
• provision of alternative hosts
• avoidance or amelioration of unfavourable conditions, for example careful timing
of weed, soil and water management operations biological agents - use enemi
causing organisms, for example, No Gall for Crown Gall in stone fruit
• chemical agents such as protectants and eradicants

20. Plant pest transmission
• With the exception of tobacco mosaicvirus, relatively few viruses or viroids are spread
extensively in the field by contact between diseased and healthy leaves. All viruses that
spread within their host tissues (systemically)can be transmitted by grafting branches or
buds from diseasedplants on healthy plants. Natural grafting and transmissionare
possibleby root grafts and with parasitic dodder(Cuscuta species).
Vegetative propagation often spreads plant viruses. Fifty to 60 viruses are transmitted in
seed, and a few seed-borneviruses, such as sour-cherry yellows,are carried in pollen and
transmitted by insects.
• Most disease-causingviruses are carried and transmitted naturallyby insects and mites,
which are called vectors of the virus. The principal virus-carrying insects are about 200
species of aphids,which transmit mostly mosaic viruses,and more than 100 species
of leafhoppers,which carry yellows-typeviruses. Whiteflies, thrips, mealybugs,plant
hoppers, grasshoppers,scales,and a few beetles also serve as vectors for certain viruses.
Some viruses may persist for weeks or months and even duplicatethemselves in their
insect vectors; others are carried for less than an hour. Slugs, snails,birds, rabbits,
and dogs also transmit a few viruses, but this is not common.

21. Continue
• A small number of plant viruses are soilborne. Viruses causing grape
fanleaf, tobaccorattle, and tobacco and tomato ring spots, as well as
several strawberry viruses, are spread by nematodes feeding
externally (i.e., ectoparasitic) on plant roots. A few soilborne viruses
may be spread by the swimming spores of primitive, soil-inhabiting
pathogenic fungi, such as those causing big vein of lettuce, soilborne
wheat mosaic, and tobacco necrosis.
• Viruses often overwinter in biennial and perennial crops and weeds
(plants that overwinter by means of roots and produce seed in their
second year or during several years, respectively), in plant debris,
and in insect vectors. Plants, once infected, normally remain so for
life.

22. Control plant pest virus
Chemical Control
The most frequently used pesticides are fungicides,
insecticides, herbicides and miticides but there are
also nematicides, molluscicides and petroleum oils.
The way in which a pesticide works is known as its
mode of action. Understanding the modes of action
of pesticides may help in deciding the best pesticide
to use. Understanding the life cycle of pests and the
developmental stagesof crops is vital in terms of
targeting vulnerable stages of pest organisms with
control measures. The decision to use pesticides
should take into account the level of disease or pest
in the plantings, the stage of development of the
plants and weather and other environmental
conditions.

23. Continue
Physical and Mechanical Control
This is one of the oldest methods that has been in
use. It includes measures like the collection of
egg masses and other inactive stages and the
removal of intested parts or whole plants. This
method can prove to be etfective during the
initial stage of the pest incidence and when
practised as a concerted effort by a large number
of farmers in a particular area.
Biological Control
The biological control involves a large scale
multiplication of natural enemies and reiease of
such organisms, or creating conditions under
which the naturally occurring organisms can act
etfectively.

24. Continue
Cultural control in agriculture
Deep ploughing after harvesting the crop (to expose
the hiding and resting insects), adjusting the time of
sowing (to avoid the peak incidence period), clean
cultivation, the removal of alternativewild hosts, catch
crops and suitable rotations are some of the important
measures included under this method of control. Oats
are an important element of crop rotation, suppressing
the wheat disease ‘take-all
Cultural control in horticulture
Proven disease-free planting material should always be
used. Many diseases "carry over" in roots, leaves,
unharvested fruit and infected wood. Diseased wood
should be pruned out and burnt together with normal
pruning's. Pruning and fruit thinning practices that
improve aeration, light penetration and drying of the

25. List of plant disease
1. Apple mosaic Virus (Chestnut mosaic)
• Distribution
Apple mosaie virus is one of the oldest knoun and most widespread apple viruses Occur in
Bangladesh, Japan, Turkey. Africa, North and South America and many European countries.
• Host Range:
65 wordy and herbaceous species in 19 families
• Symptoms
Infected trees develop pale to hright cream spots, bandings or patterns on leaves. These
spots may become necrotic after exposure to summer sun and heat. Premature defoliation
may occur when infection is severe. Except in severe cases, infected trees can prodace a
crop, with yield reductions from no reduction to 50%.
Transmission
• Virus is transmitted by grafting, budding and by vegetative propagated rootstocks
• No reported insect vectors for the virus. Management
• Use healthy propagated material
• For inuctivating the virus, cuttings, heat therapy
• Heat treatment at 36°C for 3 to 10 weeks
• Cross protection

26. 2. Apple ring spot
• Distribution
This disease has been known in New Zealand in 1935. Disease finst described in
1954. occurs only sporadically, so its ecenomic importance is slight
•Host Range:
Malus pumila. Chenopodium quinoa (Seed)
•Symptoms
Small yellow spoits, sometimeschlorotic rings on the leaves Darker green spots or
imegular rings on the fruits The skin around the lesions light green or yellow color
In ripening fruit, the surface of the spots become rough and rusty No internal fruit
symptoms Flavor and storage properties of the fruits are not affected. The spots
decrease their marketability
• Transmission
Virus is transmitted by grafting, budding and by vegetative propagated rootstocks
•Management
• Use healthy propagated material
• Removal of infected trees

27. 3. Mosaic of sugarance
• Distribution
Widely distributed and best known of virus discase. Initially repots in Juva in 1891 • Now occur in
India. North and South America and many Pacific and Atlantic islnds.
• Host range
hs host range is very wide - Sugarcane, Maize. Sorghum, elephant grass ete. • Symptoms
First symptom appear about 6 weeks after planting
• Primary and critical symptom is appearance of pale patches or blotches in green tissue of leaves
• Patches are oval or elongated lying parallel to midrib
• Tillers become erect, stiff and crinkled
• Mottling of stem also occur lead to death of cells
•Transmission
Transmission by disease cane sets used seed About 7 species of aphid are involved in virus
transmission Control measures
• Use of selected healthy sets for seed
Heat therapy is effective against certain strains
• Elimination of the grass hosts Use resistant or tolerant varieties.

28. 4. Apple flat virus
• Distribution
This disease has been known in Spain, New York, America, Eastern Washington and Hood River Oregon. Host
Range: Maluspumila and Cherry
•Symptoms
This may cause cell death at the graft union
The resulting symptoms are those of decline, collapse, or tree breakage.
Fruits are smaller, flatter, and show a tendency for the calyx end to be open.
•Management
Plant virus-indexed trees.
If replantingin virus-infected areas of the orchard, use both rootstocks and scions that are tolerantof the
virus.
•Causativeorganisms and Transmission
Causativeiseasesare caused by Flat Apple Virus.
iseases virus is transmitted by nematodes, Xiphinema americanum
. • Management
Use virus-tested certified material.
Use a disinfoctant on contaminatedpruningor cutting equipment.
Temperature therapy of infected stock

29. 5. Citrus tristeza virus
• Distribution
CTV is one of the well known and most widespread citrus virus. Occur in Spain, France, Japan,
Florida, Australia and US
• Host Range
: CTV infects several species of the plant genus. Citrus, orange sweet orange, grapefruit, lime and
Seville.
•Symptoms
CTV symptoms are associated with viral disruption of phloem and its function.
There are three distinct syndromes of CTV infection: quick decline, stem pitting, and seedling
yellows,
Alfects the cambium layer below the bud union and prevents evelopment of
In severe case, leaving fruit shri veled on the tree and leaves brown and dehydrated.
•Transmission
Ansmissionnriezavirus (CTV) is transmitted by several aphid species in a semi- persistentmanner
•Manegement
Ristezaolerantscion varieties for stem pitting, Avoid illegally import citrus material. Infected trees
must be removed immediately