Early season thrips infestations and preemergence (PRE) herbicide applications and their interaction with weather can impact early season cotton growth. Research was conducted in 2013 and 2014 in Mississippi to evaluate the impact of planting date, varietal maturity, and PRE herbicide on thrips infestations in cotton. Delta and Pine Land (DP) 0912 B2RF (short-season), and DP 1252 B2RF (full season) cotton varieties, were planted in mid-April, mid-May, late-May, and mid-June. Acceleron® N seed treatment (thiamethoxam + pyraclostrobin +abamectin) was utilized on seed at each location. Fluometuron + S-metolachlor was applied PRE at 1.12 + 1.07 kg ai ha-1and a non-herbicide treated check was included for comparison purposes. Cotton biomass at the two-leaf stage was greatest when DP 0912 B2RF was planted in late-May at 3.2 g per five plants. Cotton treated with fluometuron + S- metolachlor PRE had less biomass at the two-leaf stage than cotton not treated with a PRE herbicide. Immature thrips counts were greatest on late-May planted cotton at both the two- and four-leaf stages. Cotton height at the four-leaf stage was greatest when DP 0912 B2RF was planted in mid-June or in the absence of PRE herbicide application. Delayed maturity was observed when planting occurred after mid-May. Cotton treated with S-metolachlor + fluometuron yielded significantly less than cotton not treated with a PRE herbicide. Lint yields were greatest when DP 0912 B2RF was planted in mid-April, mid-May, and late-May or with DP 1252 B2RF planted in mid-April and mid-May. Lint yields from these combinations ranged from 2195 kg ha-1 to 2429 kg ha-1.
