JACKSONVILLE, Fla. -- An aggressive program of closing or remodeling older units has helped Winn-Dixie Stores here generate sales and earnings increases for the second quarter and 28 weeks ended Jan. 11. Net income rose 5.8% to $67.5 million for the 16-week quarter and 7.8% to $107.5 million for the year to date. Sales increased 4.6% to $3.54 billion for the quarter and 4.8% to $6.13 billion for the 28 weeks. Same-store sales rose 2.7% for the quarter and 3.1% for the year to date, while average store sales jumped 6.1% for both periods. During the first half of the year Winn-Dixie opened or acquired 42 new stores averaging 46,400 square feet and closed 43 older stores averaging 26,700 square feet. It also remodeled or enlarged 42 units. As of Jan. 11 the company operated 1,158 stores, compared with 1,172 a year ago. Of the total, 673 are larger than 35,000 square feet. Winn-Dixie has 52 stores under construction, and the company said it expects to open 80 new stores and to enlarge or remodel 90 existing stores by the end of the year. Gary Giblen, managing director of Smith Barney, New York, said he anticipates more top-line growth now that Winn-Dixie has completed its store closing program.