1.   A tillage method involving no weeding or tilling before planting has increased the use of Roundup, a chemical herbicide.

2.   But what is driving its success is a conventional chemical herbicide developed more than two decades ago.

3.   In both cases, their appetites allow states to reduce the use of chemical herbicides.

4.   In turn, farmers have grown more dependent on chemical herbicides and synthetic fertilizers, which boost yields and make it easier to farm more land.

5.   Proponents of fungal herbicides say they may prove to be much less damaging to the environment than chemical herbicides that are now typically used to fumigate drug fields.

6.   Until there is firm proof that chemical herbicides are to blame, the United States says it cannot take responsibility.

7.   What keeps Monsanto healthy is Roundup, a chemical herbicide developed more than two decades ago.

8.   What keeps Monsanto healthy is Roundup, a conventional chemical herbicide developed more than two decades ago.