Reduction in insecticide usage in cotton,maize etc
It is hard to say.
In China, Pesticides are less than before as many researcher mentioned,but not relevant to Bt-crop extension in some degrees.
The cropping structure is changing rapidly, it is decided the pesticide use such as the pesticide amount, type and spraying methods. In other word, cropping structure can affect the pesticide use. We can not distinguish the effect or interaction between Bt-crop and cropping landscape to influence the amount of pesticides in really. This is not taken into account in this kind of research.
Lu
Hi Shashikant,
According to ISAAA report at website below:( https://isaaa.org/resources/publications/pocketk/5/default.asp ):
"Since 1996, farmers planting biotech crops have reduced pesticide inputs in their fields by 8.8% or over 503 million kg which led to an overall reduction in the environmental footprint of biotech crops by 18.7%.
The largest environmental gain was recognized in fields where HT soybeans were planted. The volume of herbicides used by HT maize farmers has decreased by 203.2 million kg over the past 17 years (1996-2012). Similarly, significant reductions in pesticide loads were experienced by farmers planting insect resistant (IR) maize and cotton."
ISAAA is an organization which provides all kinds of databases, yearly reports and updates related to GM plants. If you have time, you should go and visit its website.
Not only the reduce of using pesticide and herbicide benefits the environment, also very important, it benefits the farmers' health greatly.
See this report [ http://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=13054 ]
A study shows that GM rice significantly decreases pesticide use and adverse effects on farmers' neurological, hematological, and electrolyte system. The study is published in Science China Life Sciences journal.
Results showed that commercialization of GM rice may reduce pesticide use by more than 2/3. This equals a pesticide reduction of more than 196,000 tons in China per year. The authors indicated that about 8% of rice farmers still suffer from acute pesticide-related poisoning. Thus, the estimated 16 million farmers who suffer acute poisoning illnesses each year can benefit from the use of GM technology and the consequent reduction in pesticide exposure. Hence, the commercialization of GM rice is expected to improve the health of farmers in those countries, where pesticide application is necessary to mitigate crop loss.