Velvetleaf Control as Influenced by Herbicide Placement and Seed Depth

Abstract

In a 3-year field study, from 51 to 1% of seed of velvetleaf(Abutilon theophrastiMedic) planted at 1 and 6-inch depths, respectively, produced established plants. Utilizing a microplot technique, 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) and the ammonium salt of 3-amino-2,5-dichlorobenzoic acid (amiben) were applied at 2 and 3 lb/A, respectively, at soil depths of 0, 2, and 4 inches. Velvetleaf seed were planted at depths of 1, 2, and 3 inches. Compared with the number of plants establishing in untreated plots, surface-applied amiben reduced the number of established plants 39, 23, and 29% from seed planted at depths of 1, 2, and 3 inches, respectively. Amiben at or below seed depth gave over 95% control, and when applied below the soil surface but above the seed, 86% control. Atrazine, surface-applied, reduced weed establishment 33, 62, and 85% from seed planted at depths of 1, 2, and 3 inches, respectively. When atrazine was at, below, or above the seed but below the soil surface, control was 96% or higher.