Which preposition to use with conductive

in Occurrences 2%

The most sensitive cell ever produced, previous to my investigations, was one made by Dr. Werner Siemens, which was 14.8 times as conductive in sunlight as in dark.

to Occurrences 1%

So Keith returned to the tin soldiers that were his most cherished toysperhaps because they drew fewer protests from above than anything else, as being least conductive to outbursts of youthful vivacity.

Which preposition to use with  conductive