WHAT ARE BIO CONTROL WHAT ARE BIO CONTROL AGENTS ? AGENTS ?

A system of controlling plant pests, A system of controlling plant pests, nematodes and diseases without the use nematodes and diseases without the use of chemicals, by employing of chemicals, by employing

predators, predators,

microbes, microbes,

parasites that feed upon them. parasites that feed upon them.

http://www.eeb.uconn.edu/people/Samples/GettingStarted/1-Design/index.html

Trichoderma sppTrichoderma spp

The fungal genus The fungal genus TrichodermaTrichoderma contains contains species that have the potential to be of species that have the potential to be of economic importanceeconomic importance

Species in this genus are useful in the Species in this genus are useful in the biological control of soilborne diseases biological control of soilborne diseases (19) and tree decays. (19) and tree decays.

Some species produce useful bio Some species produce useful bio chemicals and antibiotics and others are chemicals and antibiotics and others are involved in plant disease . involved in plant disease .

Evaluation of Trichoderma spp as biocontrol against nematodeThe implementation of Trichoderma in IPM can

be achieved using a soil treatment which reduced amounts of fungicides

Trichoderma harzianum & T. lignorum isolates were tested for their nematicidal activity against the root-knot nematode Meloidogyne javanica It is suggested that the main antinematode activity caused by

T. harzianum takes place in the soil and not within the roots.

MycoparasitismLytic enzyme

chitinase

Induced systemic resistance

AntibiosisTrichodermin , dermadin,

trichoviidin

Competition Solubilization & sequestration of inorganic

plant nutrients

Antagonistic fungus

Many species of Trichoderma viridae Trichoderma harzianum Trichoderma koningi Trichoderma longibrachiatum Trichoderma hamatum

Commercial formCommercial form

Bacteria –Bacteria –PPseudomonasseudomonas fluorescensfluorescens Members of the genus display the following Members of the genus display the following

defining characteristics:defining characteristics:- Rod shaped - Rod shaped - Gram-negative - Gram-negative - One or more polar flagella, providing motility- One or more polar flagella, providing motility- Aerobic, although some species have been - Aerobic, although some species have been

found-to be facultative anaerobes found-to be facultative anaerobes (e.g. (e.g. P. aeruginosaP. aeruginosa) ) - Non–spore forming - Non–spore forming - Positive catalase test- Positive catalase test

BIO FILM FORMATION

Slime production also contributes to surface-colonising biofilms which are difficult to remove from food preparation surfaces

MECHANISM OF ACTIONMECHANISM OF ACTION

Antibiotic-mediated suppressionAntibiotic-mediated suppression -phenazines, tropolone, pyrrolnitrin-phenazines, tropolone, pyrrolnitrin Siderophore – mediated supressionSiderophore – mediated supression -produce fluorescent siderophores which -produce fluorescent siderophores which

link with supression abilitylink with supression ability Induced systemic resistanceInduced systemic resistance -activates multiple defence mechanism-activates multiple defence mechanism

Some keys APPLICATION: - Soil-borne pathogens are controlled with the use of seed

treatments or hopper-box applications and foliar pathogens by spray applications

PRODUCT SPECIFICATIONS: • Storage conditions: - Store in a cool, dry place in a sealed container ENVIRONMENTAL IMPACT AND NON-TARGET

TOXICITY: - P. fluorescens. occurs widely in nature and is not

expected to have any adverse effects on non-target organisms.

P. P. fluorescencefluorescence

Pasteuria penetransPasteuria penetrans

Very effective against root knot nematodes Very effective against root knot nematodes in many crops. in many crops.

The lifecycle has four stagesThe lifecycle has four stages

-spore formation-spore formation

-vegetative growth-vegetative growth

-fragmentation-fragmentation

-sporogenesis-sporogenesis

characterscharacters

Pasteuria penetransPasteuria penetrans and related forms are and related forms are considered as potential biological control agents considered as potential biological control agents of phytoparasitic nematodes.of phytoparasitic nematodes. Host adhesion is one of the most critical steps Host adhesion is one of the most critical steps in the life-cycle of in the life-cycle of PasteuriaPasteuria.. The endospores are released in soil by The endospores are released in soil by decaying hosts decaying hosts The endospore represents the parasite durable The endospore represents the parasite durable stage as well as the infective propagule stage as well as the infective propagule responsible for transmission. responsible for transmission.

Endospore formationEndospore formation

Pasteuria Pasteuria endospore endospore from from Helicotylenchus Helicotylenchus lobuslobus

Pasteuria Pasteuria endosporesendospores

adhering to the cuticleadhering to the cuticle

of of Hoplolaimus galeatusHoplolaimus galeatus

AM Arbuscular MycorrhizaeAM Arbuscular Mycorrhizae

A symbiotic relationship with legumious A symbiotic relationship with legumious plants.plants.

The VAM fungi penetrate the living cells of The VAM fungi penetrate the living cells of plants without harming them, and form the plants without harming them, and form the typical organs, such as vesicles and typical organs, such as vesicles and arbuscles, in the root .arbuscles, in the root .

VAM fungi-infected plants have high VAM fungi-infected plants have high potential of resistance to soil potential of resistance to soil environmental stresses. environmental stresses.

ROLEROLE

The known functions of VAM fungi on The known functions of VAM fungi on plants are thatplants are that

1) the absorption of minerals, especially P, is 1) the absorption of minerals, especially P, is promoted, promoted,

2) growth is stimulated, 2) growth is stimulated, 3) high quality of fruits is produced every year, 3) high quality of fruits is produced every year, 4) resistance to environmental stresses is 4) resistance to environmental stresses is

enhanced, and enhanced, and 5) resistance to soil disease is enhanced 5) resistance to soil disease is enhanced

CONSIDERATIONS

While using care for

Cut down the amount of agrochemicals and chemical fertilizers applied.

Use fermented organic matter.

Use soil conditioners, such as charcoal and zeolite.

Consider the effectiveness of grasses

. Improve soil pH and aeration.

Commercial formCommercial form

VAM fungiVAM fungi

Characters of desirable Characters of desirable bio control agentsbio control agents

An desirable bio control agents should An desirable bio control agents should have following characteristicshave following characteristics

It should not be pathogenic to plants, animals, It should not be pathogenic to plants, animals, human beings and microorganisms.human beings and microorganisms.

It should have broad spectrum of activity in It should have broad spectrum of activity in controlling many types of diseases and must be controlling many types of diseases and must be genetically stable.genetically stable.

It should have fast growth and sporulationIt should have fast growth and sporulation It must be cultured under artificial mediaIt must be cultured under artificial media

Contd ……….Contd ……….

The innoculam must be capable of abundant The innoculam must be capable of abundant production using conventional methods such production using conventional methods such as liquid fermentation and withstanding term as liquid fermentation and withstanding term storage until applicationstorage until application

It should be amenable for inexpensive mass It should be amenable for inexpensive mass multiplication and economically viable.multiplication and economically viable.

It should have long shelf lifeIt should have long shelf life It must be efficacious under different It must be efficacious under different

environmental conditions.environmental conditions. It should be compatable with bio fertilizersIt should be compatable with bio fertilizers

Contd….Contd….

It have host susceptibility to the action It have host susceptibility to the action by the seed treating chemicalsby the seed treating chemicalsIt should not be toxic to beneficial It should not be toxic to beneficial organisms in or on the target area.organisms in or on the target area.It should be easily formulated and It should be easily formulated and method of application must be method of application must be convenient and compatible with convenient and compatible with common cultural practices.common cultural practices.

Contd…

It should easily establish in the soil with high persistence and survival capacity

It should be biologically competitive with microorganisms

REFERENCE nematologists.org.au/Jan01/paecilomyces. htm Biological control of crop diseases - D. Dinakaran, G.Arjunan, G.Karthikeyan.

www.ibioc.com/biocontrol

nematode.unl.edu/wormepns.htm - www.nysaes.cornell.edu/ent/biocontrol/pathogens/nematodes.html