*Delayed rains, fertilizer shortage and pests [on Bt cotton] are the factors

GUNTUR: Cotton farmers in the district are in disquiet at the worrying prospects over a drastic fall in yield. Ironically, the bad news comes at a time when the remunerative price offered for cotton is at its highest, in the last decade. Cotton Corporation of India (CCI) which commenced purchasing of cotton in the district on Friday offered Rs.3,000 per quintal as M.S.P, but the farmers in the district have been distraught at the prospects of a drastic fall in the production.
 
The agricultural officials and farmers point out two important factors that affected the yield. If the scanty and delayed rainfall hampered the sowing operations, the pest resistant BT cotton crop was ravaged by a variety of pests including, 'Nandedu' pest and 'Pandaku' pest. The non-availability of mixed fertilisers was also another crucial factor that affected the production.

The BT seed, which was introduced recently, was a big draw and the yield was not less that 15 quintals per acre. With the BT variety proving its disease resistant capabilities [GMW: it doesn't have any, Bt confers resistance to a specific cotton pest], most of the farmers have opted for BT seeds.

However, this time, agricultural officials point out that BT Cotton seed, which had proved its resistance against Kaya purugu had become vulnerable as it was affected by a pest known as Rasam purugu. An agricultural official pointed out that it was too late to act and hoped that the yield might be as less as was being predicted now.

Effects of Bt Corn and Cotton on Non-Target Insects - The USDA Agricultural Research Service reports that " ... Non-target insects are probably affected more by conventional insecticides than by crops that contain genes from the soil bacterium Bacillus thuringiensis (Bt) ... The researchers concluded that when it comes to killing non-target insects, no treatment at all has the least impact. Bt crops have considerably less impact on non-target insects than do conventional insecticides. Also, insecticides affect insect populations uniformly, regardless of whether they're in Bt or non-Bt crop fields ...."

Document Title: The title of the November 24, 2008 USDA ARS News Release is "Non-Target Insects Probably Affected More by Insecticides than by Bt Crops"

The title of the May 7, 2008 PLoSOne article is "Bt Crop Effects on Functional Guilds of Non-Target Arthropods: A Meta-Analysis"

Author(s): The authors of the May 7, 2008 PLoSOne article, titled "Bt Crop Effects on Functional Guilds of Non-Target Arthropods: A Meta-Analysis" are

L. LaReesa Wolfenbarger1, Steven E. Naranjo2*, Jonathan G. Lundgren3, Royce J. Bitzer4, Lidia S. Watrud5

1 Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, United States of America 
2 USDA-ARS Arid Land Agricultural Research Center, Maricopa, Arizona, United States of America 
3 USDA-ARS North Central Agricultural Research Laboratory, Brookings, South Dakota, United States of America 
4 Department of Entomology, Iowa State University, Iowa, United States of America 
5 U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Western Ecology Division, Corvallis, Oregon, United States of America

Organization: USDA Agricultural Research Service

Summary: The text of the November 24, 2008 USDA ARS News Release follows

Non-target insects are probably affected more by conventional insecticides than by crops that contain genes from the soil bacterium Bacillus thuringiensis (Bt), according to the findings of a study by Agricultural Research Service (ARS) scientists and cooperators. The findings were published recently in Public Library of Science ONE.

Bt crops such as maize and cotton are genetically engineered to produce insect-specific toxins. They target specific insect pests, but the researchers wanted to determine how these crops influence non-target insects in the environment.

To find out, scientists from ARS collaborated with researchers at the University of Nebraska at Omaha, Iowa State University and the U.S. Environmental Protection Agency. Steven Naranjo, a research leader at the ARS Arid Land Agricultural Research Center in Maricopa, Ariz., and Jonathan Lundgren, an entomologist at the ARS North Central Agricultural Research Laboratory in Brookings, S.D., contributed to the work.

The scientists compared the abundance of groups of non-target insects. They first compared the abundance of these insects in Bt crops and non-Bt crops without any insecticides. They also compared the insect populations in both types of crops treated with insecticides. And they compared the non-target insect populations in Bt crops without insecticides versus the populations in non-Bt crops treated with insecticides.

They formed these groups of non-target insects with data drawn from a modified version of a public database created by Santa Clara University biologist Michelle Marvier and colleagues. The toxins examined included Cry1Ab and Cry3Bb in maize, Cry3A in potato and Cry1Ac and Cry1Ab in cotton.

The researchers observed considerable variability in the effects of Bt cotton and maize crops on non-target insects. However, the data within the groups were fairly consistent. The most influential factor was the insecticide applied. Collectively, insecticides such as pyrethroids, organophosphates, carbamates and neonicotinoids had larger negative impacts on non-target insects than did the Bt crops.

The researchers concluded that when it comes to killing non-target insects, no treatment at all has the least impact. Bt crops have considerably less impact on non-target insects than do conventional insecticides. Also, insecticides affect insect populations uniformly, regardless of whether they're in Bt or non-Bt crop fields.

ARS is a scientific research agency of the U.S. Department of Agriculture.

The text of abstract of the PLosOne article follows

Background

Uncertainty persists over the environmental effects of genetically-engineered crops that produce the insecticidal Cry proteins of Bacillus thuringiensis (Bt). We performed meta-analyses on a modified public database to synthesize current knowledge about the effects of Bt cotton, maize and potato on the abundance and interactions of arthropod non-target functional guilds.

Methodology/Principal Findings

We compared the abundance of predators, parasitoids, omnivores, detritivores and herbivores under scenarios in which neither, only the non-Bt crops, or both Bt and non-Bt crops received insecticide treatments. Predators were less abundant in Bt cotton compared to unsprayed non-Bt controls. As expected, fewer specialist parasitoids of the target pest occurred in Bt maize fields compared to unsprayed non-Bt controls, but no significant reduction was detected for other parasitoids. Numbers of predators and herbivores were higher in Bt crops compared to sprayed non-Bt controls, and type of insecticide influenced the magnitude of the difference. Omnivores and detritivores were more abundant in insecticide-treated controls and for the latter guild this was associated with reductions of their predators in sprayed non-Bt maize. No differences in abundance were found when both Bt and non-Bt crops were sprayed. Predator-to-prey ratios were unchanged by either Bt crops or the use of insecticides; ratios were higher in Bt maize relative to the sprayed non-Bt control.

Conclusions/Significance

Overall, we find no uniform effects of Bt cotton, maize and potato on the functional guilds of non-target arthropods. Use of and type of insecticides influenced the magnitude and direction of effects; insecticde effects were much larger than those of Bt crops. These meta-analyses underscore the importance of using controls not only to isolate the effects of a Bt crop per se but also to reflect the replacement of existing agricultural practices. Results will provide researchers with information to design more robust experiments and will inform the decisions of diverse stakeholders regarding the safety of transgenic insecticidal crops.

Source: November 24, 2008 USDA ARS News Release and access to the study on the PLoSOne www site

Web site: The November 24, 2008 USDA ARS News Release is posted at  http://www.ars.usda.gov/is/pr/2008/081124.htm

The May 7, 2008 article, titled "Bt Crop Effects on Functional Guilds of Non-Target Arthropods: A Meta-Analysis" published on the PLoSOne www site is posted at 
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0002118#abstract0

Contact: Reprints and questions may be directed to Steve Naranjo who is a Research Leader and Entomologist with the USDA ARS Arid-Land Agricultural Research Center in Maricopa, Arizona at 520 316 6333; fax: 520 316 6330; e-mail: Steve.Naranjo@ARS.USDA.gov