Using steam and a low dose of herbicide helped control goat weed in citrus better than a higher dose of herbicide, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers found.
Goat weed, which poses major challenges for citrus, is found throughout the Southeast — from Texas, east to South Carolina and south to Florida. “It produces many seeds and is relatively tolerant to many of the herbicides utilized in citrus production,” said Ramdas Kanissery, lead UF/IFAS researcher on a new goat weed control study.
“To put things into perspective, it takes three to four times the usual herbicide dose to control goat weed in citrus groves compared to other weeds,” Kanissery said. “Our previous research has shown that steam application can weaken even tough weeds.”
The intense heat from steam makes the water inside the cells of weeds turn into vapor fast. This rapid change builds up pressure, causing the cells to burst and disrupts their normal functions. This weakens the weed, making it more susceptible to further damage, Kanissery said.
Kanissery, assistant professor of horticultural sciences at the Southwest Florida Research and Education Center (SWFREC), teamed with Yiannis Ampatzidis, UF/IFAS associate professor of precision agriculture engineering, to build a machine. They sprayed steam, followed by paraquat, on goat weeds growing in citrus tree rows. The results were encouraging.
For the experiment, scientists aimed to weaken goat weed with steam and enhance the impact by applying a contact herbicide like paraquat. Kanissery called this a “double whammy” approach.
“This approach can control weeds in citrus orchards. It reduces the chemical footprint on soil and groundwater, provides effective weed control and reduces the probability of developing resistance in goat weed against high dosages of paraquat use in the future,” Kanissery said.
Learn more here about steaming for weed management in citrus.
Source: UF/IFAS