Resource Book on Horticulture Nursery Management

At present, more than 21,500 naturally occurring microbes or their metabolites are
known to possess pesticidal properties. The sale of agrochemicals through out the world
is currently estimated to be $ 26,800 million, whereas biopesticide sales are around $ 120
million. Biopesticides sales, however, are estimated to increase at a rate of 10 to 25 per
cent per annum in contrast to static or shrinking world agrochemical market.
Viral Biopesticides:
Viral biopesticides of baculovirus group namely Nuclear Polyhedrosis Viruses
(NPVs) and Granulosis Viruses (GVs) offer great scope as crop protection agents on high
value crops such as cotton and vegetables against lepidopteran pests like Helicoverpa
armigera Hbn. and Spodoptera litura Fabr. More than 500 baculovisurses (BVs) have
been reported so far. Some of the insect pests from which occlusion viruses have been
reported in India have great potential in IPM.
HNPV infected Catterpilar of Tomato Fruit Borer
Bacterial Biopesticides:
Many spore forming and non-spore forming bacteria are known to be effective
against a wide spectrum of insects and pests. The crystalliferous Bacillus thuringiensis
(Bt) has been found to be effective against several species of lepidopteran pests. Its
insecticidal activity is primarily caused by parasporal crystal (delta endotoxin) produced
during sporulation. The discovery of isolate capable of acting against coleopterans (B.
thuringiensis tenebrionis and B. sphaericus against mosquito and B. moritai against
dipteran insects has further extended the scope of bacterial insecticides. Several bacteria
like, Pseudomonas fluorescens, Bacillus subtilis, Streptomyces nigrifaciens,
Agrobacterium radiobacter and Azotobacter spp. are known to be potential bio-agents
against several plant pathogen. Most of these bio-control bacteria are, however, in the
stage of empirical application, either in the green house or in the field with a few
exceptions. There are reports of bacterial bio-agents in enhancing the growth and greater
root volumes of crop plants when applied as seed treatment or soil application. This
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