CREATE TABLE table_16724844_1 (mens_open VARCHAR2, mens_u20 VARCHAR2)

What was the mens open when the mens u20 was Qld Country Rustlers def Southern Suns?
SELECT mens_open FROM table_16724844_1 WHERE mens_u20 = "Qld Country Rustlers def Southern Suns"
SELECT "mens_open" FROM "table_16724844_1" WHERE "Qld Country Rustlers def Southern Suns" = "mens_u20"