This investigation was carried out at El-Serw Agricultural Research Station, Damietta Governorate and Mansura unit Research during 2005 and 2006 seasons to study the purpose was to the effect of irrigation intervals i.e 14, 21 and 28 days and potassium fertilizer rates i.e 0, 24 and 48 Kg K₂O/feddan on yield and seed quality of five grain sorghum cultivars, i.e. Dorado, Giza 113, Giza 15, Shandawheel - 2 and Shandawheel - 6. The experiment was laid out in a split plot design with three replicates. Results showed that prolonging irrigation intervals decreased number of days to 50% heading, panicle weight, panicle grain weight, seed index, grain yield/ feddan and seed quality traits, as well as germination percentage and rate, plumule length, radical length, seedling dry weight, accelerated aging and electrical conductivity of the produced grains in both seasons. Irrigation at 28 days interval caused 30.91% and 30.41% reduction in grain yield per feddan in 2005 and 2006 seasons, respectively, compared with that of 14 days interval. Increasing potassium fertilizer rate up to 48 Kg K₂O/feddan increased all studied traits. Applying potassium at the rate of 48 Kg K₂O/feddan gave 15.31% and 15.32% increase in grain yield/ feddan compared with unfertilized plants in 2005 and 2006 seasons, respectively. Grain sorghum cultivars differed in grain yield and all studied traits in both seasons. Hybrid Shandawheel 6 was superior in grain yield per feddan compared to other tested varieties in both seasons. The interaction effects were significant on almost studied traits in both seasons. Generally, it could be concluded that sowing hybrid Shandawheel- 6 and fertilized with 48 Kg K₂O /feddan plays a prominent role in increasing grain yield/ feddan  and quality of produced seeds under irrigation water shortage (14 days interval) in North delta of Egypt.