Response: The short answer is no. Christ is not referred to as the Righteous Barley, or the Righteous Blade of Grass, or the Righteous Cereal Grain. Christ - the Firstfruit - is referred to as a Branch… the Righteous Branch.
Here’s the long answer:
Firstfruits are a shadow of Christ… for Christ is the Firstfruit of the resurrection (1 Cor 15:20-23). Throughout the writings of Moses and the Prophets, the Creator and Author of the story uses a branch to represent Christ. That is why Christ is referred to as a Branch… the Righteous Branch (Jer 23:5, Jer 33:15, Isa 11:1, Zec 3:8, Zec 6:12).
Nowhere in the Scriptures is Christ referred to as the “Righteous Blade of Grass” or the “Righteous Cereal Grain”. Rather, Christ is referred to as a branch… of a tree… for men are as trees and are known by their fruit.
Even the very definition of firstfruits disqualifies barley. Here is the Strong’s entry for firstfruit (H1061):