Adrian Diel

August Friedrich Adrian Diel (4 February 1756 – 22 April 1839) was a German physician and founder of pomology at the turn of the 19th century.

In 1782 he became physician for Hesse-Darmstadt and in 1786, Diel served as practitioner of the Count of Spaur, who was Judge at the Imperial Court in Wetzlar, and dealt mainly with Balneology.

In Diez, in the property known up to this day as "House Eberhard", which his wife had brought into the marriage, Diel planted extensive orchards with reportedly up to 12,000 apple trees.

[citation needed] Diel gained importance as a breeder of fruits and as an author of pomological writings, and laid the basis for the rise of that science in the 19th Century.

The introduction of cherries at higher elevations in the Lahn area, and the Nassau government regulation on planting fruit trees by the roadsides and on creating orchards in schools goes back to his initiative.