The CBOT came under pressure Thursday from a combination of end-of-year profit taking and rains that are pushing into southern Brazil. Traders were eager to book profits in ag commodities after their Christmas-time rally with only two trading days left in the year. Commodities have been excellent investments this year and funds are looking to close the books with above-normal returns. The proximate catalyst for Thursday’s selling, however, was rains that fell across southern Brazil on Wednesday. Brazil’s Parana and Mato Grosso do Sul states received 0.25-1 inches of rain overnight and central/northern Brazil received as much as 2.5 inches. The 7-day forecast calls for better chances of rain across central Brazil that will pus...