How can you raise Pfr value in Soyabean plant ? What is the effect of raised Pfr value?

Soyabean is a short day plant : The Pfr form of phytochrome is converted in Pr form by exposure of red light (wavelength 660 nm). The Pfr form is considered as the biologically active form of phytochrome.Germination and other phytochrome controlled processes are promoted by Pfr