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  • From: Allan Balliett <igg AT igg.com>
  • To: Market Farming <market-farming AT lists.ibiblio.org>
  • Subject: [Market-farming] More on those Nematodes
  • Date: Sun, 29 Jan 2006 23:01:31 -0500

from www.biodpectrumindia.com

Indigenous Biopesticide takes on agricultural pests

Rolly Dureha
Friday, November 11, 2005

Indigenous Biopesticide takes on agricultural pests
ICGEB scientists have developed "Bioprahar", a microbe-based biopesticidal formulation effective against a range of pests of agronomic importance.
Scientists at the New Delhibased International Centre for Genetic Engineering and Biotechnology (ICGEB) have developed a bacterial formulation for the control of a range of agricultural pests. Named as "Bioprahar", the formulation is being commercially launched by Nirmal OrganoBiotech Ltd, its industry partner, in 2005. The formulation has been found effective in controlling diamond-back moth in cabbage and cauliflower; white woolly aphids in sugarcane; mealy bugs in grapes, citrus and mango; and white ants in teak plantations.
The active ingredient of the biopesticide formulation developed by ICGEB is Photorhabdus luminescens sub sp. akhurstii, a bacterium, which resides in the intestinal tract of nematode Heterorhabditis indica. This bacterium secretes several extracellular macromolecules, which are lethal to pests.
Due to their mutualistic association with Photorhabdus bacteria, nematodes of the genus Heterorhabditis are well known parasites against insect pests. They are commonly used in pest management programs to control soil borne pests. The modus operandi of this symbiotic pair is that on entering the insect, Photorhabdus is released into the host gut where they multiply rapidly and kill the insect. They also degrade the insect upon which the nematodes feed and multiply.
Taking this lead forward, scientists (Dr Raj Bhatnagar and Dr Raman Rajagopal) of the Insect Resistance Group at ICGEB, isolated and characterized the bacterium strain from a Heterorhabditis nematode species prevalent in the southern part of India and evaluated its efficacy against several pests. In parallel, the researchers purified and studied the insecticidal toxin complex produced by the bacterium. Their studies showed that this complex is lethal to pests and is responsible for the death of the insect.
After having finished this groundwork, came the tricky task of making an effective formulation. Speaking about this uphill task, Dr Bhatnagar said, "The biggest challenge was to make a viable formulation, which does not require a cold chain. Though initial studies showed good results, application in the open fields remained a challenge. We prepared a liquid formulation consisting of the bacterium and the growth medium, but its shelf life was very short. The formulation was then further fine-tuned and stabilized with emulsifiers and stabilizers so that it remains biologically active for a longer duration".
"Presently the biopesticide formulation consists of the bacterium, surfactants and adjuvants. Its shelf life is over a year with no drop in the potency or efficacy of the formulation,"
he added.
The field tests were conducted in agriculture fields together with Dr NGV Rao at Punjabrao Deshmukh Krishi Vidhalaya (PDKV), Akola against the diamond-back moth pest of cauliflower and cabbage; Vasant Dada Sugar Institute, Pune against the white wooly aphids of sugarcane; and the fields of commercial alliance partner Nirmal Biotech against mealy bugs of grapes, mangoes and citrus. A specific regimen of spraying on each crop was developed and the results obtained after two growing seasons revealed excellent control of the targeted pests. Overall the efficacy of the formulation was comparable to any chemical pesticide.
Significantly the application of chemical pesticides in protection of cabbage and cauliflower from pests is second to cotton. It has been shown that "Bioprahar" effectively controls these pests and will thus reduce usage of chemical pesticides in these crops to a large extent.
Similarly, sugarcane production in India has suffered immensely during the last couple of years due to the white wooly aphids. "Our field evaluation data, at six districts in Maharashtra revealed effective control of white wooly aphids. This formulation will minimize the problems faced by sugarcane farmers because of wooly aphids. Nearly 90 percent control of the white wooly aphids was seen in sugarcane fields," explained Dr Bhatnagar.
The effective control of mealy bug in the case of citrus, grape and mango is expected to promote organic farming paradigm and make the production export competent. In addition, the biopesticide displayed excellent control of termites. It was found that the whole colony of white ants collapsed in 24-48 hours.
Simultaneous evaluation of mammalian toxicity at two different independent laboratories, PDKV, Akola and National Toxicology Centre, Pune, demonstrated the safety of formulation based on standard tests. The formulation did not show any allergenicity, toxicity or any other side effects against rabbit, mice or rats.
The patent for "Bioprahar" and "Biowooly Kill", a related formulation for white wooly aphids, has been filed in India and PCT countries in 2004.
Rolly Dureha



  • [Market-farming] More on those Nematodes, Allan Balliett, 01/29/2006

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