The researchers studied how the timing of planting and the amount of seeds used affect the growth and yield of winter wheat. They found that planting later led to lower grain production, mainly due to fewer grains per ear and lighter grains. Using more seeds increased the number of ears but decreased the number of grains per ear and grain weight. Early planting with high seed rates didn't affect yield much, but late planting with more seeds increased yield by producing more ears. The age of the tiller affected grain yield, with earlier tillers producing more and heavier ears. The timing of tillering was also influenced by planting date, with early planting leading to more tillers in autumn and winter, while late planting resulted in more tillers in spring.