Abuur nooc ka mid ah weedhan oo aad u adag koritaanka degdegga ah ee Elm-ka ee deegaankiisa hooyo waxay soo jeedineysaa firfircoonida hybrid F1.
Dabcan, nooc ka mid ah weedh adag oo weedhan ah waa "Kordhinta degdegga ah ee elm-kan ee deegaankiisa hooyo waxay soo jeedineysaa F1 hybrid vigor, in kasta oo geedka loo tixgeliyey Green Green, P. S. (1964)".