22 April 2002
BT COTTON AND AGRICULTURAL PROBLEMS
from SCOPE's GMF-science email list
***
1. Bollworm can go out of hand - thanks BT cotton
2. High N challenges defence of plants
***
1. Sub: Bollworm can go out of hand - thanks BT cotton
Fertility of land will further go down due to more usage of Urea and other chemical fertilizers will also increase
Due to increasing usage of urea and other chemical fertilizers in agricultural crops, agricultural pests including american bollworm are going out of hand especially in cotton. The situation is so alarming that the multinational companies like Monsanto in connivance of local scientists have virtually declared our indigenous seeds worthless and have got the BT Cotton (which comes under dangerous substances under Environment Protection Act, 1986 and handling, buying, selling of these type of seeds is punishable under section 15 of the same act) cleared from the Indian Government on 26 March, 2002. Monsanto has made false claims of controlling bollworm in cotton.
The resistance of BT Cotton against bollworm and related pests of butterfly family is due to a protein [called Cry 1 A(c)]. As revealed by research at international level (for example see the Research Paper by Dr C E Coviella and his two colleagues R D Stipanovic, J T Trumble : Journal of Experimental Botany February 2002; Volume 53(367):323-31; Title of the Research Paper: Plant allocation to defensive compounds: interactions between elevated CO(2) and nitrogen in transgenic cotton plants. The abstract of this paper is enclosed at the end of this letter) the fertilizer requirement of this dangerous plant is very high which may further deteriorate fertility of our lands. It is known that due to the use of high dosage of nitrogenous and other fertilizers the carbon content of plants decrease compared to nitrogen, which results in lowering in concentration of natural defence molecules like tannins, gossypol, etc., which adversely affects the natural control mechanisms of insects in cotton.
I am worried that as shown by extensive available research due to BT cotton the damage due to bollworm and other insects will increase and heavy dosage of fertilizers will become more prevalent and we will lose the remaining fertility of soils very fast.
We are advising the farmers to grow only the indigenous seeds of cotton, which are well suited to local climatic conditions at a distance of 3 to 5 feet so that natural defence mechanisms based on secondary metabolites like gossypol, tannins, etc. is efficiently utilised. we are requesting farmers to use of organic manures like vermicompost, green manuring, etc. instead of harmful chemical fertilizers which lead to lowering of the defence mechanisms based on secondary metabolites.
(S K Kaura)
Co-ordinator, ECO-India
***
ECO-India, 10-C Friends Colony, Hisar-125 001; India
Telephone: 91-16 62-291 63; Email: ecoindia@mailcity.com
Web site: www.geocities.com/ecoindia
ECO-India is a voluntary & non-profit organisation working in the field of environment protection and natural farming
***
2. The abstract of the paper mentioned above:
High N challenges defence of plants: J Exp Bot 2002 Feb;53(367):323-31
Plant allocation to defensive compounds: interactions between elevated CO(2) and nitrogen in transgenic cotton plants.
Coviella CE, Stipanovic RD, Trumble JT.
Department of Entomology, University of California at Riverside, Riverside, California 92521, USA. coviella@ucrac1.ucr.edu
Plant allocation to defensive compounds in response to growth in elevated atmospheric CO(2) in combination with two levels of nitrogen was examined. The aim was to discover if allocation patterns of transgenic plants containing genes for defensive chemicals which had not evolved in the species would respond as predicted by the Carbon Nutrient Balance (CNB) hypothesis. Cotton plants (Gossypium hirsutum L.) were sown inside 12 environmental chambers. Six of them were maintained at an elevated CO(2) level of 900 micromol mol(-1) and the other six at the current level of approximately 370 micromol mol(-1). Half the plants in each chamber were from a transgenic line producing Bacillus thuringiensis (Bt) toxin and the others were from a near isogenic line without the Bt gene. The allocation to total phenolics, condensed tannins, and gossypol and related terpenoid aldehydes was measured. All the treatments were bioassayed against a non-target insect herbivore found on cotton, Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae). Plants had lower N concentrations and higher C:N ratios when grown in elevated CO(2). Carbon defensive compounds increased in elevated CO(2), low N availability or both. The increase in these compounds in elevated CO(2) and low N, adversely affected growth and survival of S. exigua. The production of the nitrogen-based toxin was affected by an interaction between CO(2) and N; elevated CO(2) decreased N allocation to Bt, but the reduction was largely alleviated by the addition of nitrogen. The CNB hypothesis accurately predicted only some of the results, and may require revision. These data indicate that for the future expected elevated CO(2) concentrations, plant allocation to defensive compounds will be affected enough to impact plant-herbivore interactions.