I may suggest following web info available...Best..

https://www.cabdirect.org/cabdirect/abstract/20103246189

Heterosis is the advantage of a hybrid over the inbred parental lines. If the hybrid out performs the parents it is a definite indication of heterosis concept and the value it provides. This could occur by the hybrid better more productive for instance than the mean of each parent in a yield test for example or it can be from the hybrid out yielding both parents. The amount of heterosis is related to combination of the parental lines in the hybrid as not all combinations show significant heterosis. The heterosis we vary by species also. The identification of heterosis is determined by trialing inbred parents and comparing the results to hybrids from these parents. In the maize genetic industries hybrids are used almost exclusively because of their superiority and I would suggest consulting the maize literature using hybrid vigor testing methodology and evaluation as a search term. 

My dear, please check the following article it will be very useful for you:

https://www.researchgate.net/publication/268263138_Heterosis_and_combining_ability_for_grain_yield_and_its_components_in_sorghum_Sorghum_bicolor_L_Moench

Article Heterosis and combining ability for grain yield and its comp...