Pāṇini, ArthŚā, Bṛsam and Vṛkṣ(s) define the word [for wheat] as a type of grain distinct from barley and rice […] Additionally, NāmaMā makes a curious remark: it is a mlecchabhojya, a food of barbarians‘.
Source, in full
WOJTILLA 1999: The Sanskrit Godhūma Apropos of a short Incursion in Indo-European and Indo-Aryan prehistory. Wojtilla, Gyula. Akademiai Kiadoi, Budapest, 1999. (WOJTILLA 1999:228). Quoted in Talageri, S. G. (2010). The Rigveda and the Avesta. New Delhi: Aditya Prakashan. (WOJTILLA 1999:226-227)