Measures of Dispersion and Variability: Range, QD, AD and SD
Pathology of oak
1.
2. OAK:
Oak is a tree or a shrub and
have approximately 6oo species.
It have spirally arranges leaves with lobate
margins in may species .some have entire
leaves. Single oak produces male and
female flowers. Fruit is nut like acorn borne
in a cup like structure called cupules which
have one seed and rarely 2 or 3 seeds.
3. Uses:
1) It is used for construction of furniture.
2) Its bark is also rich in tannin and used for
tanning leather.
3) bark of this tree is also used in making
wine stoppers ( cork ).
4) Oak tree produces acorn which is use to
flaver the coffee
4. 5) Oak have also medical application. White
oak is use in creams because it contain zinc,
calcium, iron and vitamin B12.
Tea made from white oak has also been
used in curing gallstones and kidney stones.
5. DISEASES OF OAK PLANT
FUNGAL DISEASE:
GANODERMA ROOT ROT:
Ashelf like
fruiting structure form singly on the base of
the tree or near the soil line. It is brown or
reddish brown on the top with the cream or
white margin. The white portion appear to
have been varnished. The underside of the
6. shelf Is light colored with tiny pores in
which spores are present . It is also
called artist's conk.
Spores Ganoderma
9. Causative agent:
Ganoderma applanatum
SYMPTOMS:
1) infected trees slows growth rate.
2) they have dying branches with small
yellow leaves.
3) Trees affected by fungus rot may
exhibit yellowing, wilting, or
undersized
10. leaves and dead branches.
4) The first visible sign of infection is
often the formation of fruiting bodies
on the lower trunk and exposed root
areas.
Trees fall due to severe decay of roots
11. SPORES : ( 4.5-6µm)
Spores are oval in shape and brown in
color.
ODOUR / TASTE :
Amashroomy odour and bitter taste.
SEASON :
Perennial but releasing spores in late
summer and autumn.
12. HOSTS:
1) oak
2) maple
3) apple
4) elm
5) willow
GANODERMAAS A HOST:
a fungus called forked fungus beetle
feed on it. This fungus is edible but due to
its bad taste its not eaten by humans.
13. Management:
1) Although it may require several year for
the tree to die.And infected tree possess a
hazard.Atree with fungal fruiting structure
on it should be removed it.
2) Also remove the cutted parts of the tree
as it contain the spores which may infect the
healthy trees.
14. GANODERMA LIFECYCLE:
1) Spores released during summer humid
period.
2) Spores infect open wound of the root
and lower trunk.
3) Spores germinate .
4) the conk produce each year.
5) the amount of the decay wood increases
year after year resulting in the soft spongy
wood, the area where the plant anchor.
16. BACTERIAL DISEASE:
BACTERIAL LEAF SCORCH:
Browning of oldest leaves along their
margin begin in mid to late summer on one
branch or few branches.
Causative agent:
Xylella fastidiosa
- gram –ve bacteria
- rod shape
-genome consist of circular chromosome
and 2 plastids.
17. HOSTS:
X. fastidiosa has a very wide host
range that encompasses over 30 plant
families. Hosts trees include elm,
sycamore, bur, pin, oak, sugar and
red maple, mulberry and sweet gum.
Bur plant pin plant
18. SYMPTOMS:
1) The browning of leaves progress to
include more leaves towards
the end of branches.
2) Branches and entire tree die.
19. 3)Awaxy reddish brown band
sometimes develop between the brown
and green tissues of leaf.
20. DISEASE CYCLE:
The bacterium has been found in a large
number of herbaceous and woody plant host.
Xylem-feeding sharpshooter leafhoppers and
spittlebugs are known to spread the bacterium
in grape , OAK and peach and are believed to
be the vectors . In some hosts, the pathogen
can spread through root grafts.
21. MANAGEMENT:
Oxytetracyclin injections can alleviate
the symptoms the year the tree is injected
but it doesn’t cure the diseased tree.
Symptoms will reappear in the year in
which no injection is given.
22. VIRAL DISEASE:
SUDDEN OAK DEATH (SOD):
This disease kills the whole tree. It
was first discovered in California. It effect
23 species in 12 plant families. E.g.
Ericaceae .
In 2000 the pathogen causing SOD was
isolated was named as Phytophthora
ramoram.
25. SYMPTOMS:
1) The first symptom is red to black color
thick sap bleeding from the surface of the
bark. these are termed as bleeding cankers.
26. 2) The disease can be recognize by the
wilting new shoots, and
older leaves become pale.
After two or three weeks
foliage become brown.
3) In many cases the tree die.
27. MANAGEMENT:
1) Removing of infected oaks.
2) Removing of plant debris.
3) Replanting after removal of infected
trees.
4) One phosphonate fungicide,Agri-Fos, is
registered as a preventative treatment for P.
ramorum