Abstract: In a field experiment with splitsplit plot design, the effects of sowing date and planting density on the grain’s protein component and quality of strong gluten wheat cultivar Linyou 145 and medium gluten wheat cultivar Linyou 2018 were studied. The results showed that proper sowing date brought the highest protein content and yield in wheat grain. With sowing date postponed, the grain’s gliadin and glutenin contents of Linyou 145 increased obviously, while those of Linyou 2018 changed little. The grain quality of Linyou 145 was more affected by sowing date, compared with that of Linyou 2018. When sowing at proper date, the grain’s protein and glutenin contents had significant correlations with its wet gluten content, sedimentation value, dough stability time, softness, and evaluation value; while when the sowing date postponed, there existed a positive correlation between the contents of gliadin and wet gluten. The change of the proportions of different protein components in wheat grain induced by the variation of sowing date could be the main reason of the improvement in wheat grain quality. Within the test range (2.25 million -3.75 million plants·hm^-2) of planting density, the grain’s protein content was less affected, but the grain quality of Linyou 145 was affected to a certain extent. Low planting density (2.25 million plants·hm^-2) brought the best grain quality of Linyou 2018.

Key words: hilly region, economic fruit forest, plant interplanting, slope cropland, soil aggregate