The researchers studied how different amounts of wheat and a weed called holy thistle compete with each other in fields in Pakistan. They found that the weed was more aggressive in the second year due to more rain, which affected wheat yield. More weeds led to lower wheat yield, especially with fewer wheat plants. The more weeds or wheat plants there were, the more sunlight they blocked. Wheat grew better with medium seeding rates, while the weed thrived with fewer wheat plants. Both species caused lower crop yields as their densities increased. The weed's seed production depended on its biomass, which was lower with more wheat plants but still high. Simply planting more wheat couldn't completely control the weed.