Demonstrators planted coconut trees and waved signs in rallies across the Hawaiian Islands as part of an international day of protests against agriculture business Monsanto.

The protesters on Saturday complained about the effects that companies like Monsanto have on the community when they spray fields with chemical pesticides. They say they want agribusiness companies to stop using Hawaii as a testing ground for pesticides and genetically modified foods.

"Get off the island," said Diane Marshall, a Honolulu teacher. "I would like to see them close up shop."

In Waikiki, a man wore a gas mask in front of a statue of surfer Duke Kahanamoku to demonstrate the dangers of pesticides. Others in bikinis talked with tourists about why they don't want genetically modified goods to be grown in Hawaii.

"What's cool about doing it in Waikiki with the tourists is it's kind of giving them a light on what the issues are in Hawaii — that it's more than just paradise," said Nathaniel Whittaker, 28, of Honolulu.

On Maui, a group spent the day sowing fields with crops to encourage local farming. An estimated 200 demonstrators planted 2 acres of sweet potatoes, banana starts and more than 100 coconut trees, said Courtney Bruch of GMO Free Maui.

"We know that we have the power in our hands to become self-sustainable, growing our own healthy food," Bruch said.

The Maui group was joined by Neil Young, who performed a song from his upcoming album called "The Monsanto Years," Bruch said.

"It's pretty amazing he came out to this farm for this event," Bruch said.

Pake Salmon lives on Oahu but flew to Maui to take part in the planting event.

"We have all these chemical companies poisoning the land, poisoning the reef and the sea and the fishes," Bruch said.

There has been little scientific evidence showing that foods grown from GMO seeds are less safe than their conventional counterparts, but fears persist in Hawaii and elsewhere.

An Italian scientist's review of 10 years of research, published in 2013, concluded that the scientific research conducted so far has not detected "any significant hazard directly connected with the use of GM crops."

The Center for Science in the Public Interest, a critic of food companies and artificial and unhealthy ingredients in foods, has not opposed genetically modified foods, on the basis that there's no evidence they are harmful.

"We know that people have different points of view, and Monsanto Hawaii is committed to having an open dialogue about food and agriculture," Monsanto spokeswoman Monica Ivey said in an email. "Safety is our top priority, and we conduct rigorous and comprehensive testing on each and every one of our products."

Cathy Bussewitz, The Associated Press