MADISON — Tomato grower Backyard Farms, which has had to destroy two crops of tomato plants this summer, said on Monday its head grower, Tim de Kok, has resigned.

The company said the resignation of de Kok had already been planned and was coincidental to the recent move to destroy one crop due to a whitefly infestation and a second crop due to weak seedling plants.

Backyard Farms said it was in the process of searching for a replacement for de Kok.

Backyard Farms previously said a new batch of tomatoes won’t be available in stores until early 2014.

The company typically produces more than 27 million pounds of tomatoes each year in greenhouses that cover 42 acres in the western Maine town of Madison.