You can prepare the citrus vinaigrette and the pecans ahead of time; store them in the refrigerator.
Heat oil in a nonstick skillet over medium heat; add pecans. Sprinkle with sugar and red pepper; sauté 2 minutes or until sugar begins to brown. Remove from heat.
Combine greens and citrus vinaigrette in a large bowl; toss gently. Arrange 1 1/2 cups on individual salad plates; top with pecans and oranges.