SAO PAULO- Unfavorable weather caused second corn yields in the center-south of Brazil to plunge to their lowest level in 10 years, agribusiness consultancy AgRural said on Monday, projecting productivity at 66.6 60-kilo bags per hectare.

After drought then frosts spoiled much of the crop, Brazilian farmers are now expected to collect 51.6 million tonnes of second corn, almost 19 million tonnes below the 70.5 million from last season, AgRural said.

Second corn, planted after soybeans are harvested, is the country's main corn crop and accounts for 70% to 75% of production in a given year. With second corn, Brazil competes with the United States as one of the world's largest suppliers in world markets, selling to countries like Iran and Japan.

"Failure of the 2021 corn crop, planted with much delay due to the later soybean harvest, was the result of the lack of rain in most of the producing areas in April and May," AgRural said. "The frost starting at the end of June and lasting until now reduced yields and also caused quality problems."

This year, a spoiled second corn crop hurt Brazil's export prospects and increased the need to import.

On July 1, AgRural had predicted the second corn crop would total 54.6 million tonnes, but the unfavorable weather led to another revision in the projection.

The cold and damp of past weeks also limited farmers' harvesting pace, with growers collecting only 49% of their corn area in the center south through last Thursday, below the 61% at the same time in 2020, AgRural said.

(Reporting by Ana Mano Editing by David Holmes) ((; Tel: +55-11-5644-7704; Mob: +55-119-4470-4529; Reuters Messaging: