Fungal Nematicides

1. Shariqa Jan
Department of Bioresources
Contact: rasoolshariqa@gmail.com

2.  Introduction
 Nematicides
 Types of nematicides
 Nematophagous fungi
 Nematode trapping and its various mechanisms
 Endoparasitic nematode
 Egg parasites
 Root-knot (nematode disease)
 Paecilomyces lilacinus as nematicide

3.  Nematodes are nonsegmented roundworms belonging to the phylum
Nematoda.
 They are colorless and lack appendages.
 Nematodes mat be free-living, predaceous, and parasitic.
 They have a flexible outer cuticle that protects them.
 Move via muscular system.
 Most lay eggs.
 Predominantly pathogenic for plants.
 Some are human parasites and others are animal parasites.
 Enemy_ Nematophagous fungi.

4.  A Nematicide is a type of chemical pesticide
used to kill plant-parasitic nematodes.
 Nematicides have tended to be broad-spectrum
toxicants possessing high volatility or other
properties promoting migration through the soil.
TYPES OF NEMATICIDES
1. Natural Nematicides
 Garlic developed polysulfide product.
 Neem cakes.
 Root exudates of Marigold( Tagetes)
 Nematophagous fungi
Nematophagous fungi

5. 2. Artificial Nematicides
 Fumigants
 Carbamates
 Organophosphates

6.  Eating of Nematodes by Fungi is called Nematophagy.
 Fungi mechanically attack and kill the worms resulting in consumption of
the worm.
 Nematophagous fungi are obligate parasites of Nematodes.
 Majority of them are facultative saprophytes.
 They are used for biological control of plant- parasitic nematodes.
 Nematophagous habitat evolved from lignolytic and cellulolytic fungi as
an adaptation to overcome competition for nutrients in soil.

7. 1.Nematode- trapping fungi
2.Endoparasitic fungi
3.Egg parasites
NEMATOPHAGOUS FUNGI

8. They trap nematode host and kill them.
 They have structural adaptations.
 They are predatory/ endoparasites.
MECHANISM OF TRAPPING
i) Adhesive hyphae
ii) Adhesive branches
iii) Adhesive nets
iv) Adhesive knobs
v) Non- constricting rings

9. ADHESIVE HYPHAE
Nematode contact with fungal hyphae
Worm remains in contact by means of secretions or coated adhesives by fungi
Secretion of yellow, thick chemical
Hyphal outgrowth development
Complete trapping of worm
Inactivation of worm
Worm cell penetration by hyphae
Elongation & nutrient absorption by hyphae
Death of worm

11. ADHESIVE BRANCHES
 Small and simple organ of capture.
 They arise from main hyphae as short laterals and grow as erect branches on
or below the substrate.
 Is coated with a thin film of adhesive material.
 Example of fungi : Dactylella cinopaga

12. ADHESIVE NETS
 They are formed by adhesive fungal hyphae.
 Nets may be single loop like to complex multibranched network.
 Example: Anthrobortrys musiformis

13. ADEHISIVE KNOBS:
 Distant adhesive globose – sub- globose cell
in structure.
 Action:
Production of a thin adhesive film over the
knob surface
Nematode trapping by knob
Attack by several more knobs
Nematode death

14. NON- CONSTRICTING RINGS
 Formed by erect, lateral branches that arise
from the prostrate creeping septate hyphae.
 Action:
i) Slender branch of fungi widens.
ii) Branch curls to form circular structure.
iii)Cell wall of stalk & tip of branch fuses at the
point of contact.
iv)Forms 3- celled ring with stalk.
v) Nematode entry into the ring.
vi)Nematode struggling to escape.
vii) Breakup of weak points of the ring.
viii) Worm carrying ring.
ix) Gradual penetration of nematode by the ring.
x) Nematode death.

15.  Produce mycelium external to nematode body.
 Bring structural modifications to kill their prey.

16.  Contact between fungi and nematode egg.
 Hyphae develops a terminal swollen structure.
 Hyphal narrow infectious tube develops.
 Tube penetrates the egg shall.
 The hyphae consumes the egg nutrients.

17.  Root-knot nematodes are plant- parasitic nematodes from the genus
Meloidogyne.
 They exist in soil in areas with hot climates or short winters.
 Root-knot nematode larvae infect plant roots, causing the development of
root-knot galls that drain the plant’s phoyosynthate and nutrients.
 Infection of young plants may be lethal, while infection of mature plants
causes decreased yield.
Root-knot
disease

18.  Paecilomyces lilacinus acts as a biocontrol fungus as it protects the root
system against diseases caused by plant parasitic nematodes, specifically
root-knot nematodes.
 This bio-agent colonizes the root surface and is strongly parasitic to egg
and egg-masses of plant parasitic nematodes.
 P. lilacinum produces proteases and a chitinase, enzymes that could
weaken a nematode egg shell.

19. DOSAGE:
 5 kg/ha preferably with 2 tons of any organic matter.
NURSERY BED TREARMENT:
 50gm/sq.m
SEED TREATMENT:
 Treat 10gm/kg seed
APPLICATION GUIDELINES:
 Apply near the root zone, preferably leaving a 7 day gap on either side
before applying nematicide.

20. • http://www.plantdiseasehandbooktamu.edu
• http://www.britannica.com
• http://worldwidescience.org
REFRENCES: