So let's run some numbers....
Japanese researchers have inserted a gene from the human liver into rice to enable it to digest pesticides and industrial chemicals. The gene makes an enzyme, code-named CPY2B6, which is particularly good at breaking down harmful chemicals in the body.
Present GM crops are modified with genes from bacteria to make them tolerate herbicides, so that they are not harmed when fields are sprayed to kill weeds. But most of them are only able to deal with a single herbicide, which means that it has to be used over and over again, allowing weeds to build up resistance to it.
But the researchers at the National Institute of Agrobiological Sciences in Tsukuba, north of Tokyo, have found that adding the human touch gave the rice immunity to 13 different herbicides. This would mean that weeds could be kept down by constantly changing the chemicals used.