Effects of Narrow-Windrow Burning on Weed Dynamics in Soybean in Louisiana

Abstract

The soil seedbank allows for long-term persistence of weed species in agricultural fields. Some weed species can persist in the soil seedbank for extended periods. Restricting inputs into the weed seedbank has a large impact on future population density and influences management practices of these weeds in soybean production systems. Harvest weed seed control (HWSC) tactics incorporate mechanical and cultural management strategies to target weed seeds present at harvest. A 3-year trial was initiated to determine if continual use of the HWSC method, narrow windrow burning, selects for earlier seed set and shattering in Louisiana soybean. No shifts in weed populations or shattering time were observed. However, there was a significant reduction in weed density and the weed seed present in the soil seedbank when HWSC and robust herbicide programs were used in combination. Therefore, utilizing multiple effective weed management strategies is imperative in reducing the soil seedbank.

Narrow-windrow burning to control seeds of Italian ryegrass (Lolium perenne ssp. multiflorum) in wheat and Palmer amaranth (Amaranthus palmeri) in soybean

“…This study showed promise that there is no yield penalty when implementing HWSC, and it is likely that it will contribute to preventing HR development (Beam et al 2019). Patterson et al (2021) reported that NWB alone was 62% more effective at reducing the Palmer amaranth seedbank compared to conventional harvest. In the same study, Palmer amaranth seedbank size increased from 40 to 100 seeds m −2 over 3 yr under a POST-only herbicide program.…”

“…In the same study, Palmer amaranth seedbank size increased from 40 to 100 seeds m −2 over 3 yr under a POST-only herbicide program. In contrast, the use of NWB in addition to a POST-only herbicide treatment decreased seedbank density from an average of 42 to 18 seeds m −2 (Patterson et al 2021). The problematic status of Palmer amaranth as well as overall success under HWSC in soybean production demands alternative solutions such as NWB, and a determination of the temperature threshold necessary to reduce seed viability.…”