Weed Control by Spring Cover Crops and Imazethapyr in No-till Southern Pea (Vigna unguiculata)

Abstract

Studies were conducted at the Vegetable Substation in Kibler, AR, in 1992 and 1993, in the same plots, to evaluate weed suppression by spring-seeded cover crops and to determine the effects of cover crop and imazethapyr on no-till southern pea. A plot without cover, conventionally tilled before planting southern pea, served as control. Weed control treatments, applied as subplots in each cover crop, included a weedy check, handweeded check, and half and full rates of imazethapyr (0.035 and 0.07 kg/ha) followed by sethoxydim (0.22 kg/ha). Biomass of Palmer amaranth 6 WAR without herbicides, was less in Italian ryegrass and sorghum-sudangrass residues than in oat residue and no cover crop. Over the years, Palmer amaranth density increased 333% without cover crops and 28% with cover crops. Rice flatsedge density increased four to five times in oat and sorghum-sudangrass residues but remained the same in Italian ryegrass residue. In general, Italian ryegrass residue suppressed the most weeds. Oat residue was least suppressive. Italian ryegrass and sorghum-sudangrass also reduced southern pea stand. Regardless of cover crop and year, half and full rates of imazethapyr followed by sethoxydim equally reduced density of Palmer amaranth, goosegrass, large crabgrass, southwestern cupgrass, and rice flatsedge compared with the untreated check. Residual control of Palmer amaranth by imazethapyr was higher at the full rate than the reduced rate, regardless of cover crop. Half rate of imazethapyr followed by sethoxydim controlled 94 to 100% of Palmer amaranth, rice flatsedge, large crabgrass, and southwestern cupgrass late in the season, regardless of cover crop in 1992 and 1993. Southern pea yield in untilled plots with cover crops was two to three times lower than yield in plots with preplant tillage and no cover crops mostly because of reduction in crop stand in the presence of cover crops.

Effects of rye cover crop residue and herbicides on weed control in narrow and wide row soybean planting systems

“…Instead, they provide species‐specific, partial weed suppression during early season growth of summer crops (Liebl et al . 1992; Ateh & Doll 1996; Burgos & Talbert 1996; Teasdale 1996; Yenish et al . 1996; Reddy 2001b).…”

“…1999), soybean ( Glycine max L.) (Ateh & Doll 1996), and southern pea ( Vigna unguiculata (L.) Walp.) (Burgos & Talbert 1996). Rye is considered an important cover crop because of its potential to withstand harsh winter conditions and produce abundant biomass that can suppress weed germination and the emergence of certain weed species.…”

Effect of Cover Crop Management and Preemergence Herbicides on the Control of ALS-Resistant Palmer Amaranth (Amaranthus palmeri) in Peanut

“…Weed suppression may also occur from allelopathic compound that are released from cover crop residues Shilling et al, 1985;. Burgos and Talbert (1996) reported that the cover crops Italian rygrass (Lolium perenne L.), oat (Avena sativa), and sorghum-sudangrass (Sorghum bicolor-Sorghum bicolor var. Sudanese) reduced Palmer amaranth populations between 32 and 59% for 9 wk after crop planting, in the absence of herbicides.…”

Response of Soil Microbial Communities to Applications of Green Manures in Paddy at an Early Rice-Growing Stage

“…우리나라에서도 친환경농업의 실천을 위해 농가현 장에 적용할 수 있는 화학비료 대체기술로서 자운영, 청보 리, 트리티케일 등의 녹비작물이 다양하게 연구되고 있다 (Lee et al, 2009;Park et al, 2009). 그러나 논 토양에 투입된 녹비는 혐기적인 조건에서 미생물에 의해 초기에 다 량으로 분해되므로 녹비의 C/N율과 산소부족으로 인한 토 양 생태계의 심각한 변동을 가져올 수 있다 (Burgos and Talbert, 1996;Teasdale and Daughtry, 1993). 그러나 이 러한 문제점에도 불구하고 투입된 녹비가 벼 생육초기에 토 양 미생물의 다양성에 미치는 영향을 검토한 연구는 거의 없다.…”