Response of Seeded and Transplanted Summer Squash toS-Metolachlor Applied at Planting and Postemergence

Field experiments were conducted in Georgia in 2004 and 2005 to evaluate the effects of S-metolachlor on summer squash fruit yield. Main treatment effects included summer squash cultivar (yellow or zucchini), planting method (seeded or transplanted) and herbicide program (nontreated control, S-metolachlor applied at planting and prior to transplanting [PRE] at 0.5 and 1.0 kg ai/ha, S-metolachlor applied postemergence [POST] 3 wk after planting [WAP] at 0.5 and 1.0 kg/ha, and S-metolachlor applied PRE at 0.5 kg/ha followed by POST at 0.5 kg/ha [PRE fb POST]). Fruit number and weight were measured 12 times during each growing season and the harvests combined into early (harvests 1 to 4), middle (harvests 5 to 8), late (harvests 9 to 12), and cumulative (harvests 1 to 12) yield categories. Mixed-models analyses were used to evaluate the effects of herbicide rate and timing, squash cultivar, and planting method on squash yield for each harvest period. Summer squash cultivar and planting method did not affect ...