This presentation summarizes several diseases that affect the sissoo tree species (Dalbergia sissoo), including leaf spot caused by various fungi which produce yellowish or grayish lesions on leaves, leaf blight caused by Rhizoctonia solani which causes stomata-infected blotches on leaves, powdery mildew caused by Phyllactinia dalbergiae which produces a dense white mycelium on leaves, and rust disease caused by Maravalia achroa which infects seedlings. It also discusses wilt symptoms of flagging leaves and die-back symptoms of thinning foliage and drying branches. Control methods include fungicide applications and sanitation practices.

1. PRESENTATION
ON
DISEASES OF SISSOO
(Dalbergia sissoo)
Course Name: Forest Protection. FOR/3/CC/15
Course In-charge: Dr.S.Kumar
Presented by:
Baniaraplang Syiemiong FOR/15/144
Phibakordor Larisa Badwar FOR/15/145
(M.Sc.Forestry, Batch 2015-2017)
DEPARTMENT OF FORESTRY, MIZORAM UNIVERSITY, AIZAWL

2. DISEASES OF SISSOO
(Dalbergia sissoo)
Dalbergia sissoo is attacked by a number of diseases and the
details are given below:
(a) Leaf spot:
Different fungi viz., Cercospora sissoo, Colletogloeum
sissoo, Phyllachora dalbergiae, Phyllachora spissa, Phyllosticta
sissoo, Mycosphaerella dalbergiae, Myrothesicum
roridum and Alternaria alternata causing leaf spots on this
tree species and recorded from the region this tree species
grows.

3. Symptoms: (Leaf spot)
1. The pathogen, Cercospora sissoo attacks the leaves mostly on the lower
surface, producing yellowish to grayish-green discoloration. Pustules are
mostly intra-epidermal. Stomata are brown with simple or forked
conidiophores (Sydow and Mitter, 1933).
2. The pathogen, Colletogloeum sissoo causes imperceptible leaf spots and
is recorded from Varanasi, Uttar Pradesh (Pavgi and Singh, 1971).
3. The pathogen, Phyllachora dalbergiae attacks the upper leaf surface
and produces shining black cushion-like stromata which may occur
scattered or in clusters (Saccardo, 1883).
4. The pathogen, Phyllachora spissa attacks the leaves and forms densely
aggregated dot-like dark stromata on irregular brownish infection spots
and recorded from Wynaad, Kerala and Meghalaya (Bakshi, 1976);
Khandala, Maharashtra (Ananthanarayanan, 1964)
5. The pathogen, Phyllosticta sissoo causes infection on leaves. The spots
are round to irregular, greyish-brown which sometimes cover the entire
leaf surface. Dark brown pycnidia are produced on lower leaf surface in
densely aggregated groups (Saccardo, 1931).

4. (b) Leaf Blight:
Rhizoctonia web blight of sissoo caused by R. solani an anamorph
of Thanatephorus cucumeris was recorded from Dehra Dun (Mehrotra (1992b).
Symptoms:
1. The disease first appears on leaves close to the ground as water soaked grayish
brown blotches which increase in size with the advancing fungal hyphae and
ultimately the entire leaf blade is invaded by the fungus.
2. The leaflets show stromatid aggregates on the under surface and eventually
turn brown. The infected adjoining leaflets often join together by the fungal
hyphae as if caught in a spider’s web hence the name web blight.
3. Leaflets or entire leaf become detached prematurely but they remain clinging to
the stem for a considerable period as they are invariably joined together by the
fungal hyphae. There is a cluster of hyphae at the base of the petiole or petiole.
4. The disease spreads laterally through contact of overlapping foliage of the
adjoining seedlings resulting in group infection of seedlings in the nursery.

5. Control Measures: (Leaf Blight)
The disease can be effectively managed through proper sanitation, weeding and
foliar application of fungicide solution (Bayleton – 0.1% at fortnightly intervals).
(c) Powdery Mildew:
Phyllactinia dalbergiae causes powdery mildew on sissoo seedlings and recorded
from Dehra Dun and Allahabad (Uttar Pradesh), Pusa (Bihar), Poona, Bombay and
Nagpur (Maharashtra) and Chichrauli and Seonti (Haryana) (Pirozynski, 1965;
Mukerji, 1969; Singh, 1973; Mehrotra, 1992c).
Symptoms:
The fungus produces yellowish, persistent, dense mycelium on the lower
surface of sissoo leaves.
Control Measures:
Application of sulphur based fungicide was found most effective followed by
Baycor, Mortesan and Calixin in controlling powdery mildew disease on D.
sissoo seedlings in nursery.

6. (d) Rust disease:
Maravalia achroa is recorded on seedling in nurseries from Uttar
Pradesh, Bihar, Maharashtra and Assam (Patil and Thirumalachar, 1971;
Bakshi, 1976; Mehrotra, 1987). The disease also occurs on young
plantations but not in as severe form as in the nurseries.
Symptoms:
1. The disease appears in February-March on leaves and juvenile twigs and
continues attacking the foliage and young twigs up to July-August.
2. The infection declines following monsoon rains.
3. The affected parts are killed resulting in die-back and subsequent death
of affected seedlings.
4. The infected leaves are often deformed and the infected plants show
perceptible retardation in growth and look stunted and weak.

7. Control Measures: (Rust disease )
The disease may be effectively controlled
by foliar application of 0.08% Bayleton at
fortnightly intervals (Mehrotra and Pande, 1993).
(e) Wilt:
The term "wilting" or "withering" is applied to cases where the
whole plant dies suddenly from infection of fungus in the roots.
Symptoms
1. The effects produced on trees are more or less of the same type as
those produced by drought or frost, but are distinguished firstly by
the absence of these causes, and secondly by their appearance in
isolated plants or patches in the affected areas
2. This disease is identified by usual symptoms of flagging of leaves,
pods and even tender twigs.

8. (f) Die-back:
1. The die-back disease has more specialised symptoms than wilt.
2. The symptoms are thinning of leaves and crown, drying up of the
ends of the branches, table topped conditions and stag-
headedness in extreme cases.
3. Small dry twigs keep on falling continuously and the tree looks like
a blunt stub containing thick branches.
4. The die-back in a tree takes place in successive stages and is
characterised by progressive death of twigs, branches, shoots or
roots starting at the tips.
5. Staghead is a slow die-back of upper branches of a tree, and the
dead, leafless limbs superficially resemble a stag's head.

9. Control Measures: (Die-back)
1. Avoid Injury
2. Mixed Cropping
3. Sanitary Precautions
4. Deep Planting
5. Ban on Debarking
6. Site Selection
7. Removal of Over-aged Trees
8. Fungicides (Bavistin (carbendazim) and captaf (captan)
fungicides can be very effective against Fusarium solani).

10. References
1. Diseases of Dalbergia sissoo
-(agritech.tnau.ac.in/forestry/forest_disease_sissoo.html)
1. Shisham die-back in pakistan and remedial measures
-M. H. Khan
Pakistan Forest Institute, Peshawar, Pakistan
(http://www.fao.org/docrep/008/ae910e/ae910e07.htm)

11. THANK YOU