Effects of Planting Date on the Yield of Cotton Varieties at Yuma, Arizona

A field experiment was conducted in Yuma, Arizona to evaluate the effects of planting date on cotton yields. Six Upland varieties were planted on 3 dates from 15 March to 24 April in 1991. Significant differences were found among varieties at the first planting date (15 March) with full season varieties yielding higher than medium and short season varieties. No differences were found among varieties at planting dates 8 April and 24 April. Significant differences were found among planting dates for all varieties. Weather conditions in March were abnormally cool and may have negatively influenced yields from the first planting date