Rice Response to Planting Date Differs at Two Locations in Louisiana

Planting date can have a dramatic effect on crop development and yield. Determining if rice cultivars respond differently to planting date is important when selecting the most appropriate cultivar for a particular planting date. Research was conducted from 1995 through 1997 at two locations in Louisiana to determine the number of days from seedling emergence to 50% panicle emergence and rough rice grain yield of the cultivars Bengal, Cypress, Jodon, and Kaybonnet when drill seeded at five dates ranging from late March through early June. The interaction of cultivar by planting date for days required to reach 50% panicle emergence and rough rice grain yield was not significant. However, planting date had a major effect on days required to reach 50% panicle emergence and grain yield. Grain yield at one location in southwest Louisiana was highest (8600 kg/ha) when rice was planted in late March, and grain yield decreased linearly as planting was delayed until early June (6500 kg/ha). In northeast Louisiana, grain yield was lower when seeded in late March (5200 kg/ha), increased to a maximum in mid‐April (7200 kg/ha), and decreased throughout the latter planting dates. Days from seedling emergence to 50% panicle emergence decreased at both locations as planting was delayed.