Given the general interest over the past few decades in restoring heirloom vegetable and fruit cultivars, this seems both backward and abysmally stupid. The only way this might make sense is if the “goes green under prolonged light exposure” issue means that light exposure causes them to develop a toxic level of glycoalkaloids, and I couldn’t find anything to suggest that. There also seems to be some question as to whether they really are harder to machine-harvest than the worst of other varieties that remain certified.

This smells to me like there was something political involved, probably small-scale, inside the Department of Agriculture, and now lost to time.