Davis he played a major role in bringing Theodosius Dobzhansky and Francisco J. Ayala to the genetics department in the early 1970s.

He worked on developing varieties of lima beans, in addition to studying the inheritance of its seed coat polymorphisms as well as this plant's basic genetics.

And indeed starting in the early 1960s he worked with experimental populations of wheat, barley, and lima beans as well as the wild plants Collinsia, Avena barbata, and Avena fatua investigating a wide variety of issues important to the population genetics of inbreeding species.

[13][14][15][16][17][18][19] Starting at the latter part of the 1960s and to the end of his career, Allard and co-workers focused primarily in a new area for his lab, that of ecological genetics, particularly in the plant Avena barbata.

This work was greatly assisted at the end of the 1960s and throughout the 1970s and 1980s by the use of molecular markers known as isozymes combined with traditional quantitative genetics and morphological single-marker traits[20][21][22][23] [24][25][26][27][28][29][30][31][32][33][34] as well as more advanced molecular techniques as these became available in the 1980s and 1990s and were applied to Avena barbata[35] and other species such as wild and cultivated barley[36][37] and pines.

[38] An over-riding theme of Allard's lifetime work was the demonstration of "favorable epistatic combinations of alleles of different loci", or multilocus gene complexes in wild and cultivated plants that were assembled in and adapted to specific habitats.