Researchers compared different methods of weed management in two types of potato plants. They found that using a combination of a weed-killing chemical called pendimethalin and tilling the soil worked best to control weeds. Just using pendimethalin or tilling alone wasn't as effective. The combination of both methods gave the highest profits per hectare. Tilling the soil had a negative impact on potato yields, while pendimethalin actually increased yields. One type of potato, 'Red Pontiac', was better at competing with weeds than the other type, 'Red Norland'.