WATERMELON. IMPERIAL we have given the costs of these operations per hour listed on the cultural operations page. Not included in .. yield 35 to 40 tons of seedless watermelons per acre. . PROJECTED PROFIT OR LOSS PER ACRE. Jan 7, A lot of people think watermelon production is not profitable and that to make a #21, is all you need to grow watermelon on an ACRE (6 plots) of land. 35days – Bigger Fruit (watermelon increases in size per second). Jul 9, For many people, a sweet, juicy bite of watermelon on a hot day means Farmers plant 1, to 1, watermelon plants per acre.