Genetic modification can be as safe as traditional breeding. When crossing two plants using conventional breeding techniques, breeders mix thousands of genes in order to acquire one or a few genetic traits.

To remove unwanted traits, breeders spend many years back-crossing the new plant varieties repeatedly with plants whose genetic components are well known. This slowly dilutes the impact of all those unwanted genetic traits that came along with the few beneficial traits.
Genetic modification brings to traditional plant breeding the ability to move specific gene(s) instead of having to move thousands at one time.

This could prevent the introduction of unwanted traits and thereby offers a more predictable, and arguably safer method to produce plants with desirable traits.