Question

Collect information on alternative to pesticides and organic farming prepare a report

Answer 1

Answer:

It is defined by the use of fertilizers of organic origin such as compost manure, green manure, and bone meal and places emphasis on techniques such as crop rotation and companion planting. Biological pest control, mixed cropping and the fostering of insect predators are encouraged.

Answer 2

Answer:

Explanation:

1. Biological control of pest and disease helps to control excessive use of chemical pesticides and is a good alternative to it.

Examples of biocontrol:

• Ladybird: a beetle which is useful in controlling aphids.
• Dragonflies: used to get rid of mosquitoes.
• Bacillus thuringiensis (Bt): is a microbial biocontrol that are introduced to control cotton bollworm and butterfly caterpillars.
• Tricoderma: it is a fungus used in treatment of plant disease.
• Baculoviruses: they are the pathogens which attack other insects and arthropods.

        eg: Nuecleopolyhedrovirus (NPV)

• Biopesticides: includes bioherbicides and bioinsecticides.

    2.Organic farming is raising crops through the use of biofertilisers that

        provides optimum nutrients to crop plants.

        Biofertilisers are organisms that enrich the nutrient quality of soil.

The main source of biofertilisers are:

• Bacteria:

        (I) Rhizobium forms symbiotic association with root nodules of  

          leguminous plants. they fix atmospheric nitrogen into organic form.

       (II) Bacteria like Azospirillum and Azotobacter can fix atmospheric  

          nitrogen while free living in soil .

• Fungi:

       Fungi forms symbiotic association with roots of higher plants known as  

       Mycorrhiza. The fungal symbiont absorbs phosphorus from the soil

       and passes it to plants. Plants with such an association shows

       resistance to root borne diseases, tolerance to salinity and drought,  

       and overall increase in plant growth and development.

Types of Mycorrhiza:

      (I) Ectomycorrhizae (Ectotrophic or Ectophytic): Hyphae of fungus only  

      forms mantle on the outer surface of the roots , increasing absorption  

      of water  and minerals eg. pinus, oak etc. Mycorrhiza stores nitrogen,

      phosphorus, pottasium and calcium.

     (II) Endomycorrhizae (Endotrophic or Endophytic): Hyphae penetrate

     into cortex of roots eg. orchids, coffee and woody plants. They are also

     known as Vesicular Arbuscular Mycorrhiza (VAM). It has significant role

     in phosphorus nutrition in plants.

• Cyanobacteria:

       Cyanobateria are autotrophic microbes and can fix nitrogen as they

       have special cells known as heterocyst which is meant for nitrogen

       fixation. eg. Anabaena, Nostoc, Oscillatoria etc

       In paddy field cyanobacteria serve as an important biofertiliser.

       Blue green algae(BGA) also increases the fertility of soil  and reduces

       alkalinity.

I HOPE THIS IS HELPFUL

THANKS