The researchers studied how different planting dates affect the growth of winter wheat. They planted wheat on six different dates and found that delaying planting caused the wheat to grow faster but resulted in shorter growing periods. Late planting led to shorter plants with fewer spikes and less grain production. Harvest index increased with later planting dates, but grain yield decreased significantly, with the biggest drop seen in spring planting. However, even spring-planted wheat without vernalization could still produce a yield.