Alternative Management

An article on the control of Palmer amaranth in organic systems that will discuss the biology, Palmer amaranth weaknesses, management considerations, early detection, and elimination, managing populations in organic systems, considering cultural techniques/growing practices that are less conducive to palmer amaranth, strategic tillage, cultivation, and crop rotation/fallowing.

In Maryland, populations of common ragweed have developed resistance to three herbicide groups, Group 9 (glyphosate), Group 2 (FirstRate, Synchrony), and Group 14 (Flexstar, Valor). These herbicide-resistant populations limit options for effective postemergence control. Even though alternative herbicides are available, control can be inconsistent when applied to common ragweed plants exceeding 4” tall (Figure 1). 

Organic Weed Control in No-Till Vegetable Systems

Cover crops of rye, hairy vetch, hairy vetch+rye, tillage radish and no cover crop have been grown over the last 5 years and vegetables have been planted into these various cover crops which were managed in several different ways for weed control.