HAVANA, May 15 (Xinhua) -- Cuban leader Fidel Castro repeated Tuesday his rejection of the mass production of biofuels at the expense of food production, saying that biofuels' alleged benefits must be "debunked".

    His article, published in the Cuban state newspaper Granma, focused on the unpleasant conditions suffered by sugar cane plantation workers in Brazil, a nation that promotes the use of fuel ethanol.

    It cited a study on Brazil's manual cane harvest, written by Maria Luisa Mendonsa, an author from the Brazilian city of Rio de Janeiro.

    The study had been previously presented at the sixth Hemispheric Meeting on the Fight Against Free Trade Agreements and the People's Integration Meeting, both held this month in Havana. The study collects cane harvesters' testimony, describing terrible working conditions and salaries that barely feed and clothe them.

    Castro said these conditions reminded him of his childhood on his father's sugar plantation in Biran, more than 700 km from Havana. Castro senior was an immigrant from the Spanish region of Galicia. Cuban sugar workers were mainly Haitians and other Caribbeans suffering slavery-like conditions working United States-owned sugar companies.

    Cuba's 1959 revolution delivered Castro's father's land to the people, the article said.

    Current fuel ethanol production poisons soil and drinking water because it uses a great deal of chemicals, Castro said.

    He ended the article by expressing his deep respect for "the brother nation of Brazil" and said he supported the recent nationalization of a transnational patent for an AIDS treatment.

    In the last two months, Castro has published seven articles against biofuels and the problems that the environment will suffer as a result, and on the freeing of Luis Posada Carriles in the United States, an anti-Castro activist wanted for bomb attacks in Cuba and Venezuela.