Bountiful Plant Transpiration

Guy Kyser on Plant Transpiration, Phytoremediation

By Patrick Cavanaugh, Deputy Editor

When plants get irrigated, not only do they provide food, but all plants transpire. Guy Kyser, a specialist at the UC Davis Plant Sciences Department, explained how plant transpiration transforms carbon dioxide into “food” for plants to grow.

“Water in the shallow soil is either going to evaporate, or it’s going to be transpired,” Kyser said, “which means it’s going to pass through a plant from the soil to the atmosphere. The transpiration process helps the plant fix CO2 and convert it into food or plant material. The plant is really a little solar powered machine that catches CO2 out of the atmosphere and turns it into something solid so it’s not a greenhouse gas anymore.”

Kyser also explained the phytoremediation* process that occurs in plants grown in less-than-ideal soil and water conditions, in which these plants take up polluted water from its roots while removing impurities from the soil, retain the impurities, and release pure water into the atmosphere. Kyser said, “So, with phytoremediation, you can use the plants to purify poor soil or water situations, then mow off the plant material when the process is done. All the toxins stay in the plant, and only the pure water goes through.” Despite being a slow process, phytoremediation is effective in toxin removal, environmentally friendly, and does not harm soil health.

*Phytoremediation: Ancient Greek for “plant” and Latin for “restoring balance”

UC Research on Effects of Herbicide Milestone

Milestone, a herbicide from Dow AgroSciences, was registered about 9 years ago in California for mainly cattle ranged applications, targeting problem weeds.

Guy Kyser with the Department of Plant Sciences at UC Davis looked at how the herbicide was affecting good perennial grasses.

“Its used mostly for broadleaf weeds, its been a real help with the Yellow Starthistle. There was some concern about whether it might affect seedling grasses, especially the perennial native plants that we want to replant after controlling yellow star thistle, because it got a little bit of soil residual, which is good for thistles but we wanna make sure it wasn’t hurting our grasses, and that’s what this trial is. We treated several rates of Milestone, and replanted with several species of native California perennial grasses, to see if there was any impact on the seedlings.

Kyser found out that the important grass species are more tolerant to Milestone applied at the time of planting, then when milestone is applied to young seedlings. He noted that California Brome is the most tolerant grass to Milestone.

Kyser’s research was featured at the recent 58th annual UC Davis Weed Day.