Ceres Inc., a developer of seeds for energy crops, announced Monday that its Brazilian subsidiary has partnered with Swiss company Syngenta AG to develop sweet sorghum for ethanol production in Brazil. The Thousand Oaks company said its hybrid seeds will be paired with Syngenta’s pesticides to improve crop yields. The companies will work together on small-scale trials and larger field evaluations this season to introduce the crop as a source of fermentable sugars in Brazil’s more than 400 ethanol mills. “By working together with Syngenta, we believe we can advance the development of sweet sorghum crop management practices and provide a more complete package of advanced hybrids and leading crop protection products to our mutual customers,” said Michael Stepenson, vice president of operations for Ceres, in a prepared statement. Financial terms with the Basel, Switzerland company were not disclosed. Ceres began operations in Brazil two years ago seeking to capitalize on the country’s growing biofuels industry. The South American country is the world’s second-largest producer of ethanol behind the United States. Shares of Ceres gained 55 cents, or more than 15 percent, to close at $4.04 on the Nasdaq.