Remove skin from turkey breast, and discard. Place turkey in a heavy-duty zip-top plastic bag or baking dish.
Combine nectar and next 3 ingredients in a jar; cover tightly, and shake vigorously. Reserve and chill 3/4 cup nectar mixture. Pour remaining mixture over turkey breast, turning to coat; seal or cover and chill overnight, turning occasionally.
Combine 1/4 cup reserved nectar mixture, plums, and next 4 ingredients in a medium bowl; cover and chill at least 1 hour.
Remove turkey from marinade, discarding marinade. Place turkey on food rack over a drip pan.
Cook, covered with grill lid, 1 1/2 to 2 hours or until a meat thermometer inserted in turkey registers 170°, basting occasionally with remaining 1/2 cup reserved nectar mixture. Let stand 10 minutes before slicing. Serve with plum mixture and mixed greens.