Seedbank management through an integration of harvest-time and postharvest tactics for Italian ryegrass (Lolium perenne ssp. multiflorum) in wheat

Abstract

Italian ryegrass is a major weed in winter cereals in the south-central United States (US). Harvest weed seed control (HWSC) tactics that aim to remove weed seed from crop fields are a potential avenue to reduce Italian ryegrass seedbank inputs. To this effect, a four-year, large-plot field study was conducted in College Station, Texas and Newport, Arkansas from 2016 to 2019. The treatments were arranged in a split-plot design. The main-plot treatments were: (1) no narrow-windrow burning (a HWSC strategy) + disk tillage immediately after harvest, (2) HWSC + disk tillage immediately after harvest, and (3) HWSC + disk tillage one month after harvest. The sub-plot treatments were: (1) pendimethalin (1,065 g ai ha-1, Prowl H2O®) as a delayed preemergence application (herbicide program #1), and (2) a premix of flufenacet (305 g ai ha-1) + metribuzin (76 g ai ha-1) (Axiom®) mixed with pyroxasulfone (89 g ai ha-1) (Zidua® WG) as an early postemergence application followed by pinoxaden (59 g ai ha-1) (Axial® XL) in spring (herbicide program #2). After four years, HWSC alone was significantly better than no HWSC. Herbicide program #2 was superior to herbicide program #1. Herbicide program #2 combined with HWSC was the most effective treatment. The combination of herbicide program #1 and standard harvest practice (no HWSC) (check) led to an increase in fall Italian ryegrass densities from 4 plants m-2 in 2017 to 58 plants m-2 in 2019 at College Station. At wheat harvest, Italian ryegrass densities were 58 and 59 shoots m-2 in check plots at College Station and Newport, respectively, whereas the densities were near zero in plots with herbicide program #2 and HWSC at both locations. These results will be useful for developing an improved Italian ryegrass management strategy in this region.

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

“…Variability in both studies is attributed to differences in initial seedbank densities and Italian ryegrass seed retention and production at harvest. Maity et al (2022) found that using NWB each year for 4 yr reduced Italian ryegrass soil seedbank size by 78% in Texas, while improving wheat yield. Compared to conventional harvest, NWB reduced Italian ryegrass plant populations during the growing season by 73%, 83%, and 88% in Texas; and by 8%, 55%, and 89% in Arkansas after the second, third, and fourth year of NWB, respectively.…”

“…Compared to conventional harvest, NWB reduced Italian ryegrass plant populations during the growing season by 73%, 83%, and 88% in Texas; and by 8%, 55%, and 89% in Arkansas after the second, third, and fourth year of NWB, respectively. In combination with various herbicide treatments, their integrated management program led to large reductions in Italian ryegrass seed survival and annual fecundity (Maity et al 2022). Problematic status and a lack of regionally specific data in NWB systems makes Italian ryegrass an important candidate for this study.…”

Bioprospection of Phytotoxic Plant-Derived Eudesmanolides and Guaianolides for the Control of Amaranthus viridis, Echinochloa crus-galli, and Lolium perenne Weeds

“…crus-galli (barnyard grass) is one of the most noxious weeds in modern agriculture, and it affects relevant crops like rice, is dispersed worldwide, and has a tendency to grow in harsh climates; , and L. perenne (ryegrass), the major weed that affects wheat production worldwide …”