Based upon my experiences performing security cooperation duties in the Military Assistance Program (MAP) in Jordan, at a GCC, and at DISAM, I offer some thoughts and comments concerning the SDO/DATT concept.
No. Barley is not wheat at all. Barley and wheat are two different species of cereal grasses belonging to the family Triticeae. Barley does belong in the wheat family, which is, as mentioned, Triticeae, but is of an entirely different species from wheat. The species name for barley is Hordeum vulgare, and the species name for wheat is Triticum aestivum. No doubt either look similar, but both are quite different from the other.
Barley is a common staple in human and animal diets. Part of the grass family, it grows in over 100 countries and is one of the most popular cereal crops, surpassed only by wheat, corn and rice. Although barley is fairly adaptable and can be grown in many regions, it is a tender grain and care must be taken in all stages of its growth and harvest.