Answer: The expected phenotypic ratio is 9:3:3:1.
As per the question, purple (P) and tall (T) are the dominant traits over white (p) and short (t), which are recessive traits.
Pea plants with parental genotype PpTt will produce 4 types of gametes that is PT, Pt, pT, and pt. When the parents ( with genotype PpTt) are crossed with each other, they will produce four different types of phenotypes that is illustrated in the punnett square.