The old adage that everything is good in moderation might even come into play with deadly hydrogen sulfide gas, according to research from the University of Washington, which reports that the pungent gas implicated in several global mass extinctions will actually help plants grow if administered in low doses.

Enhanced plant growth could lead to a sharp increase in food supplies and surplus stocks of vegetation to be used in biofuels, the University reports.

"We found some very interesting things, including that at the very lowest levels plant health improves," said Frederick Dooley, a UW doctoral student who led the research. Surprisingly, Dooley added that his find was rather unexpected, since he wasn't even looking for it.

Initially he planned to examine the toxic effects of hydrogen sulfide on plants, but mistakenly used only one-tenth the amount of the toxin he intended. He thought the results were unbelievable, so he repeated the experiment, again and again, coming up with the same results so often that they are "now certainly" he said.

Testing the process on wheat seeds resulted in germination in one or two days instead of four or five. With peas and beans, the typical germination rate rose from 40 percent to as much as 70 percent for the gassed seeds.

"They germinate faster and they produce roots and leaves faster. Basically what we've done is accelerate the entire plant process," he said.

At high concentrations - levels of 30 to 100 parts per million in water - hydrogen sulfide can be lethal to humans. At one part per million it emits a telltale rotten-egg smell. Dooley used a concentration of 1 part per billion or less to water seeds of peas, beans and wheat on a weekly basis.

It was not specifically mentioned in the report whether the hydrogen sulfide-treated plants were safe to eat.