0023-6152

AA00697606

2339057

Changing temperatures is one of the major threats to the maintenance of plant yield. Shifting the planting date is the best way to cope with climate change. The aim of this experiment was to determine optimum seeding dates for sorghum × sudangrass hybrid (SSH) cultivars that can provide foundational information to develop improved forage cropping system in central reign of South Korea (CRSK). Three SSHs (Jumbo, Sordan 79 and Revolution) were seeded at four planting dates between April 20 and June 20 (April 20, May 10, May 30 and June 20), respectively. The growing period from the planting to the heading stages was shorter for the cultivars planted on May 10 and longest for those planted on April 20, while those seeded on June 20 could be harvested only once due to the short growing period. Plant height, stem diameter, leaf number, and sugar content were high in the cultivars planted on April 20 and May 10. Among the three cultivars, Jumbo was significantly taller with a large stem diameter, while Revolution was the shortest with a small stem diameter. The highest sugar content was found in Revolution and the lowest in Jumbo. During the 2–year average, the total dry matter yield from the cultivars seeding on April 20 was approximately 54% higher than that of June 20. Additionally, it was difficult to apply seeding on April 20 in the double–cropping system with winter forage because of the prolonged growing period. Based on the yield and agronomic characters observed in this study, seeding on May 10 was ideal for developing improved forage cropping system in CRSK.