ECOLOGICAL PEST MANAGEMENT

In organic farming systems pest control strategies are largely preventive, rather than reactive. Organic farming is not single method but rather a variety of techniques which are aimed at reducing costs, preserving the environment and protective human health by eliminating the toxic farm chemicals. Pest-insect, diseases causing pathogens, weeds and nematodes are estimated to cause an annual loss of about 33-35 percent of potential food production world wide.

Harmful Effects of Conventional Agriculture for the Use of Chemical Fertilizers  

1.    Killing of useful insects

2.    Residual effect on human and animal body

3.    Residual effect on environment

4.    Unavailability and high price

Due to the dangers of using chemical pesticides, there has been a considerable resurgence of interest amongst the scientists to look for alternative methods of pest control. Slowly but steadily there has been growing appreciation about the role of pest resistant cultivars, biological control agents and cultural methods in pest control. These non-chemical or ‘bio-environmental’ methods are the major components in the integrated management of pests.

The non-chemical methods of pest management certainly from the major components of Organic farming. Management for integration of non-chemical methods of controlling insect pests, disease, weeds and nematodes, is essential for successful organic farming.

1. Cultural Control

Cultural control is the deliberate manipulation of the environment to make it less favourable for pests by disrupting their reproductive cycles, eliminating their food of making it more favourable for their natural enemies.

1.1. Sanitation

1.2. Tillage

1.3. Application of Manures and Soil Amendments

1.4. Crop Rotation

1.5.Trap cropping

1.6 Intercropping

1.7 Strip farming

1.8 Time of planting

1.9 Water management

1.10 Crop competition

2.  Physical and Mechanical Control

2.1 Manual control

2.2 Burning

2.3 Solarisation

2.3 Flooding

3.  Biological control

Biological control is gaining world recognition as a primary and often essential components of successful pest management. Classical biological control involves deliberate introduction and establishment of natural enemies in areas where they did not  previously occur. Biological control agents for insect pests are available in nature abundantly.Virus like  nuclear polyhedrosis virus,granulosis virus and bacteria like Bacillus thuringensis  ,fungi like Verticillium  and protozoa cause diseases in insects and destroy them.

3.1 Conservation of natural enemies

4.  Host resistance

The use of plant varieties tolerant of or resistant to pest attack is a proven, effective, economical and safe method of pest control. Plants have diverse means to avoid , tolerate or recover from attack of other organisms. This trait is particularly important on low value crops.

*Cucumber,oat, sunflower has great availability to suppress weed

*Some crops have allelopathic effect which can suppress the weed and it is consider as a very modern technique for weed management.

The breakdown of plant resistance has become a greater problem with diseases as compared to insect pests, where it is fortunately much less common. Thus every effort should be made to use genes for resistance and tolerance obtained form diverse sources and to add them to the genes for specific resistance.

5.  Others  

5.1 Behavioural control

 a)Pheromones

  *Sex pheromones

  *Trial pheromones –helping the other individual to follow the trial left by other

  *Aggression pheromones-invoking aggression behaviour

 

Pheromones are extremely selective, non toxic, highly biodegradable and effective at very low application rates. At present all pheromones which are used in the field are mostly synthetic.eg. Synthetic sex hormones are used for lepidopterous insect.

b)Fairmones

Pheromones are volatile compounds that evoke behavioural control and released either by the host plant or by the host insects.It is used increase the efficiency of predator and egg parasitoid.