fusarium wilt

2. 1. Introduction
• Wide spread and destructive soil borne
disease
• 2-90% yield losses (Gupta et al., 1987;
Swamini et al., 1987; Kanjilal et al., 2000;
Pataky et al., 2000).
• Severe both in green house and field
conditions.

3. 2. Etiology of Fusarium
• Mycelium: Septate, branched, intracellular, hyaline
which later become cream colored in culture.
Microconidia: 1-3 celled, hyaline, ovoid or ellipsoidal
Chlamydospores: 1or 2 celled, round, double walled,
grows within or terminally from the old mycelium or
macroconidia

4. • Macroconidia: Fusiform, hyaline, mostly 2-3 septate,
pointed and curved ends.

5.  Fusarium oxysporium f.sp.psidii, Fusarium solani, Macrophomina
phaseoli, Rhizoctonia bataticola : Guava wilt
 Fusarium oxysporium f.sp. vasinfectum: wilt of cotton
 Fusarium udum: Wilt of Pigeon pea/arhar
 Fusarium oxysporium f.sp.ciceri: Chickpea wilt
 Fusarium oxysporium f.sp.lentis: Wilt of Lentil
 Fusarium oxysporium f.sp.cubense: Wilt of Banana/ Panama wilt
 Anamorph: Fusarium , teleomorph: Gibberella
 Facultative parasite
 Soil and seed borne
 Toxic substance Fusaric acid or Lycomarasmin

6. Symptoms caused by various wilt pathogen

7. Wilt of cotton
 Fungus attacks the host when the plants are 1 to 3 week
old.
 In young affected plant, the basal part becomes black
whereas in mature plants partial discoloration takes place.
 Leaves become yellow and wither at the age of 5 to 6
weeks old, finally plant dries up.
 If the attacked plant is pulled up and examined, vascular
tissues of the roots and stem are blackened because of the
plugging of vessels.
 The transverse section of the affected stem when examined
it is seen that vascular bundles are plugged with fungal
hyphae and a gummy substance.

9. Wilt of Pigeon Pea
After 5-6 weeks after sowing, the plant shows
sign of gradual wilting as if affected by drought.
Wilting causes the foliage the foliage to droop,
plant become yellow and finally plant dries up
If the infected plant is pulled out from the soil,
the blackened longitudinal streaks are seen on
the stem upto sufficient height.
Black streaks represent the vascular bundles of
the infested plant plugged with mycelium and
fructification of the fungus.

11. Wilt of chickpea and lentil
Foliage develops a grayish green chlorosis, typically
affecting lower leaves and extending up to the plant
Leaves turn dull- yellow color, wilt and plant collapses
and dries
ln some cases leaf vein clearing can be seen before
plant wilt.
Necrosis and discoloration may be seen in collar region
Plants can be easily pulled out because of weakening of
root region
In severe wilting condition the plants looks firing when
observed from long distance.

14. Wilt of Guava
• Characteristics symptom include yellowing followed by
browing and wilting of leaves from the tips
• Discoloration of stem, death of branches and complete
wilting of trees within 10-15 days.
• In advance stage wilted fruit dry and stem base cracks
• Two type of wilt noticed:
– in slow wilting leaf color changes from green to yellowish
or reddish, leaves fall, die back start and plant die in few
months
– in rapid wilt plant collapse suddenly especially after rains
and dry the leaves and defoliation occurs

16. Fusarium wilt of Solanaceous crops
•Initial symptoms are yellowing of the foliage,
beginning with the lower leaves and progressing
upward.
•Later, yellowing starts in only one side of a leaf
midrib, one branch, or one side of the affected
plant.
•Infected leaves later show downward curling,
followed by browning and drying.
•Plants infected with Fusarium wilt have a
brown discoloration of the vascular vessels.

18. Epidemiology
1. Fusarium wilt
– Temperature : 70-90°F
– Poorly drained soil
– Application of high amount of nitrogenous
fertilizers, deficiency in potassium and
– Soil acidic conditions(pH 5-6)

19. Disease cycle of Fusarium

20. Management practices
A. Cultural practices
– Use of resistant cultivars.
– Application of FYM, poultry manure and mushroom
spent substrate plus paddy straw with recommended
NPK dose.
– Soil solarization by mulching with white polyethylene.
– Fallowing of infected soil for one or two summers.
– crop rotation with non host crops for two years.
– Selection of planting materials from diseased free field.
– Prevention of leaf cutting or animal browsing in
infested plots.
– Destruction of diseased plant.

21. B. Biological control agent
Fusarium & Verticillium wilt
– Non pathogenic strain of F. oxysporum MT0062
– Bradyrhizobium japonicum
– Pseudomonas putida 89B-27
– P. fluorescens
– Talaromyces flavus
– Streptomyces spp
– Trichoderma spp
– Gliocladium virens
– Bacillus subtilis

22. C. Plant extracts(Botanicals)
• By using plant refuge or root extract of Tagetes
erecta.
• Methanol extract of palmarosa(Cymbopogon
martinii)(1%), Mentha arvensis were effective
against R. solanacearum.

23. D. Chemical control
For fungal wilt:
– Foliar spray of Prochloraz 50% wp and carbendazim
50% wp at 1.5-2 g/lit water.
– Seed treatment with captan at 75 g a.i/kg
– Propineb( Antracol) 75% wp @ 2 g/litre water