Translation:He only cultivates wheat this year.
It's unnatural to the indicative in this context. Either both tenses should be accepted or use the progressive "is growing", it's what a native English speaker would say
“El nu cultiva doar grâu...” and you could continue with saying “...ci și orez, orz, ovăz, porumb etc”
"He grows nothing but wheat this year" was not accepted. There is a consistent problem in guessing what is required as the correct answer when translating negatives, as Romanian uses the double negative and English the single negative. It is hard to know which one of the two negatives will be dropped and which kept.
Poate fi in dicționare dar nici un fermier vorbitor de limba engleză nu va zice vreodată “I’m cultivating wheat this year” ci mai degrabă “I’m planting wheat this year”/“I’m growing wheat this year”