Meanings of great agriculturists in English

When we came near a village, we saw men, women, and children employed in weeding their gardens, they being great agriculturists.

Do none of the great agriculturists themselves see how desirable such a wheat would be for the agriculture of this country?

The Quiches, like their neighbours the Cakchiquels, were a highly civilised race, possessing well-built towns, roads and the arts of life, and were great agriculturists.