This study looked at how planting density and sowing date affect the yield of a new maize variety called Shiyu No.9. They found that having around 75,000 to 82,500 plants per hectare led to the highest yields, with lower yields at 52,500 plants per hectare. Planting more or fewer than these numbers reduced the yield. They also discovered that sowing the maize earlier, around June 10, resulted in higher yields compared to later sowing dates. Overall, the best results for yield were achieved with a planting density of 75,000 to 82,500 plants per hectare and sowing the maize variety on June 10th.