A method for predicting harvestable biomass yield in a crop comprising: genotyping a sample obtained from a crop plant for one or more markers genetically linked to a polynucleotide sequence having at least 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 97, 98, 99 or 100% identity to SEQ BD NO 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25, whereby the markers individually or collectively identify a haplotype associated with yield in a plurality of crop plants and correlating the haplotype with the harvested biomass yield.