MAIZE HYBRID X90R999

A novel maize variety designated X90R999 and seed, plants and plant partsthereof areproduced by crossing inbred maize varieties. Methods for producing a maizeplant bycrossing hybrid maize variety X90R999 with another maize plant are disclosed.Methods for producing a maize plant containing in its genetic material one ormore traitsintrogressed into X90R999 through backcrossing or genetic transformation, andto themaize seed, plant and plant part produced thereby are described. Maize varietyX90R999, the seed, the plant produced from the seed, and variants, mutants,and minormodifications of maize variety X90R999 are provided. Methods for producingmaizevarieties derived from maize variety X90R999 and methods of using maizevarietyX90R999 are disclosed.