To check receptivity of stigma, Hydrogen peroxide is used at a different concentration in different stages. U need to standardized the concentration as per your cultivar too. For planning experiment, this (http://www.scielo.br/pdf/cagro/v28n5/v28n5a16.pdf) article may help you.
You can use Benzedine H2O2 testing. See African Journal of Biotechnology, Vol. 12(46), pp. 6460-6467, 13 November, 2013 DOI: 10.5897/AJB11.3594. I hope this helps :-)
To check receptivity of stigma, Hydrogen peroxide is used at a different concentration in different stages. U need to standardized the concentration as per your cultivar too. For planning experiment, this (http://www.scielo.br/pdf/cagro/v28n5/v28n5a16.pdf) article may help you.