Maachalos Assuros 10:6

Kilei hakerem refers to planting a species of grain or vegetable together with a grapevine, regardless of whether they were planted by Jews or by non-Jews, grew on their own, or one planted the vine among the vegetables. In all such cases, we may not eat or benefit from either of them as per Deuteronomy 22:9, “lest the fullness of the seed that you have planted be sanctified,” “sanctified” in this context meaning separated and prohibited.

Maachalos Assuros 10:7

One who eats an olive-sized portion of kilei hakerem, from either the vegetables or the grapes, is liable to lashes under Biblical law. Both of these can combine to reach this requisite volume.