By Rodrigo Viga Gaier and Ana Mano

RIO DE JANEIRO/SAO PAULO (Reuters) – A potential ban on the popular herbicide glyphosate in Brazil over concerns it may cause cancer in humans would be a “disaster” for the country’s agricultural industry, Agriculture Minister Blairo Maggi said on Thursday.

A Brazilian court ruled on Aug. 3 that new products containing the chemical could not be registered in the country and existing registrations would be suspended starting from September, until health authority Anvisa issues a decision on its re-evaluation of glyphosate’s safety.

Maggi said that glyphosate is used on around 95 percent of soy, corn and cotton harvested in the country and that there is no readily available substitute. Brazil is the world’s top exporter of soy and a major producer and exporter of corn.

“Glyphosate makes it viable for us to plant and grow crops. What is the alternative?” Maggi said at an event in Rio de Janeiro.

Brazil’s Solicitor General’s office has said it is preparing an appeal to the court decision with the Agriculture Ministry’s backing. Maggi said he is confident the ruling will be overturned on appeal.

The Brazilian court case is part of a global pushback against the chemical. A U.S. judge ruled last week that Monsanto must pay $289 million in damages to a man who alleged its glyphosate-based products like Roundup caused his cancer.

Monsanto, taken over earlier this year by Bayer AG, said in a statement that more than 800 reviews, including those by the U.S. environmental and health authorities, support that glyphosate does not cause cancer. The company is appealing the U.S. court ruling.

Brazil federal prosecutors brought the case to force Anvisa to make a decision in its re-evaluation of glyphosate, which it started in 2008, said Marco Antonio Delfino de Almeida, a member of a prosecutors’ working group on pesticides.

A 2015 assessment by the World Health Organization’s International Agency for Research on Cancer determined glyphosate probably causes cancer in humans, which provides a basis for reconsidering its safety, Almeida said.

If the Brazil ban on existing product registrations goes into effect, it could disrupt farmers who are set to begin planting soy in September.

The sale of glyphosate products would be halted and farmers who use products with suspended registrations could face legal risks, said Brazil-based agribusiness lawyer Frederico Favacho.

Anvisa told Reuters it is prioritizing its re-evaluation of glyphosate but did not give a timeframe for announcing its findings.

(Reporting by Rodrigo Viga Gaier and Ana Mano; Writing and additional reporting by Jake Spring; Editing by Frances Kerry and Lisa Shumaker)