Methods and hybrid seed are provided which involve growing two varieties of a field crop which is at least partially cross-pollinated in the field, wherein the two varieties are fertile with respect to both male and female functions, are selected to yield specified hybrid(s), and are distinguishable with respect to seed characteristic(s). Collected seed from the grown field crop are separated into fractions with respect to the seed characteristic, wherein at least one fraction is of hybrid seeds of the specified hybrid(s). For example, the separated fraction may be intermediate with respect to the seed characteristic(s) between seed fractions of the non- hybridized two varieties. Respective varieties may be bred to yield hybrids with required traits, which are distinguishable from the parent varieties through seed characteristic(s) such as size, weight or optical parameters that enable sorting out the hybrids from the overall crop.
