稲穂[inaho] ear (head) of rice
花穂[kasui] spike (in botany)
刈穂[kariho] harvested grain
垂り穂[tariho] drooping ears (of grain)
瑞穂の国[mizuhonokuni] Japan, the Land of Abundant Rice

穂先[hosaki] ear (e.g. of wheat)
落穂拾い[ochibohiroi] gleaning (i.e. picking up crop left after harvesting)
黒穂[kuroho] smut
穂状[suijou] shaped like an ear of grain

初穗[hatsuo] first ears of rice or crops or harvest of the season