The water in the container on the right is black with nanotubes, and the tomato plant that germinated and grew inside the container is bigger than the one on the left, which wasn't exposed to nanotubes. Credit: ACS/ACS Nano

Researchers at the University of Arkansas at Little Rock Nanotechnology Center have found that exposing tomato seeds to carbon nanotubes makes tomato plants sprout earlier and grow more quickly. They write in the journal ACS Nano that these results, though preliminary, suggest that carbon nanotubes could be a boon for the agriculture and biofuel industries and lead to new types of fertilizers:

Here, we demonstrated that the exposure of carbon nanotubes to seeds of valuable crops, such as tomatoes, can increase the germination percentage and support and enhance the growth of seedlings. Furthering these findings could result in significant developments of improved plants for the area of energy, by taking advantage of the enhancement in the biomass of the plants when they are exposed to nanosized materials and fertilizers.

It seems that the long, skinny, strawlike structures promote water uptake, because seeds exposed to carbon nanotubes contained more moisture.

This is certainly cool, but it's hard to say whether it's good news or bad. Using carbon nanotubes as fertilizer could have unintended consequences. The effects of nanomaterials on the environment, and the ways they move through organisms and the food chain, aren't very well understood. Some studies of these effects have had alarming results. In one, single-walled nanotubes were found to be toxic to fruit flies; another showed that multilayered nanotubes, the kind used in the tomato-plant study, have the same carcinogenic effects as asbestos in the lungs of mice.