scholarly journals Cover Crop Termination Treatment Impacts Weed Suppression Potential

Weed Science ◽  
2019 ◽  
Vol 67 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Erin R. Haramoto ◽  
Robert Pearce

AbstractWeed management in tobacco (Nicotiana tabacumL.) is accomplished primarily with soil-residual herbicides, cultivation, and hand removal. Management practices that reduce weed emergence, like reduced tillage and cover crop mulches, may improve weed management efficacy. Depending on cover-cropping goals, growers face trade-offs in species selection and management priorities—producing weed-suppressive mulches may lead to transplanting difficulties and soil-residual herbicide interception. Managing more complex cover crop mixtures may result in different challenges. We established on-farm trials across 4 site-years to study impacts of cover crop composition [wheat (Triticum aestivumL.) monoculture or mixture], termination treatment (early or late chemical termination or removing aboveground biomass), and soil-residual herbicides on weed density and biomass. The cover crop mixture contained cereal rye (Secale cerealeL.), crimson clover (Trifolium incarnatumL.), and hairy vetch (Vicia villosaRoth.), with canola (Brassica napusL.) at 1 site-year. The mixture typically produced more biomass than monoculture wheat, although composition had few impacts on weed density or biomass. With residual herbicides, termination treatment had few impacts on weed density, suggesting that residues did not adversely affect herbicide efficacy. Without residual herbicides, early-season weed density was often higher following the late-terminated cover crop compared with other termination treatments, though midseason weed density was typically lower. When termination treatment affected final weed biomass, it was lower following late termination, with one exception—crop establishment was reduced at 1 site-year, leading to reduced weed–crop competition and greater weed biomass. Our results suggest that growers can use mixtures and, if well-timed to a rainfall event for incorporation, still effectively use soil-residual herbicides to maintain adequate weed control in tobacco regardless of how the cover crop is managed. Later termination, resulting in more residue, may lead to less weed biomass accumulation in the absence of herbicide use.

2006 ◽  
Vol 20 (3) ◽  
pp. 733-737 ◽  
Author(s):  
Nathan S. Boyd ◽  
Eric B. Brennan

Substantial weed growth often occurs in legume-cereal cover-crop mixes commonly grown on organic vegetable farms. A 2-yr study at the USDA-ARS in Salinas, CA, was conducted to test the effect of zero, one, and two passes with a rotary hoe on weed control in a mixed cover crop of 10% rye, 15% common vetch, 15% purple vetch, 25% peas, and 35% bell bean. Rotary hoeing occurred 14–15 days after planting (DAP) in the one-pass treatment, and 14 and 28 DAP in the two-pass treatment. Rotary hoeing did not affect total cover-crop density or biomass in either year, but reduced rye density and biomass in year 2. One pass reduced total weed density by 69% in year 1 and 49% in year 2. A second pass did not affect weed density in year 1 but reduced weed density an additional 33% in year 2. One pass decreased weed biomass in year 1, whereas two passes were required to reduce weed biomass in year 2. Rotary hoeing reduced seed shed by chickweed and shepherd's-purse seeds, the two predominant weed species, by 80 to 95% in both years. Rotary hoe efficacy depended on weather conditions directly before and after cultivation. The decision to repeat rotary hoeing should be based upon field scouting and weather conditions following the initial pass with the rotary hoe.


Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Roberto Botelho Ferraz Branco ◽  
Fernando de Carvalho ◽  
João Paulo de Oliveira ◽  
Pedro Luis da Costa Alves

Abstract Cover crop residue left on the soil surface as organic mulch in no-tillage crop production provides several environmental benefits, including weed suppression. Thus, many farmers who use cover crops attempt to reduce the use of agricultural inputs, especially herbicides. Therefore, our objectives were to study the potential of different cover crop species to suppress weeds and produce an in situ organic mulch, and evaluate the effect of the organic mulch with and without spraying glyphosate on weed suppression for vegetable (tomato (Solanum lycopersicum L. and broccoli (Brassica oleracea L. var. botrytis) growth and yield. Five cover crop treatments (sunn hemp (Crotalaria juncea L.), jack bean [Canavalia ensiformis (L.) DC.], pearl millet [Pennisetum glaucum (L.) R. Br.], grain sorghum [Sorghum bicolor (L.) Moench ssp. bicolor] and a no-cover crop (control)) were used in the main plots; and spraying or no spraying glyphosate on the flattened cover crop in the sub plots of split-plot experimental design. Organic mulch from pearl millet, sorghum and sunn hemp resulted in lower weed biomass during the early season of both tomato and broccoli than jack bean and no-cover crop (control). Spraying glyphosate after roller crimping reduced weed biomass by 103 g m−2 and 20 g m−2 by 45 and 60 days after transplanting (DAT) of tomato, respectively and resulted in a better tomato yield compared to non spraying. Glyphosate reduced weed biomass by 110 g m−2 in the early season of broccoli (30 DAT), but did not affect yield. Terminating high biomass cover crops with a roller crimper is a promising technique for weed management in vegetable crops, which has the potential to reduce or even eliminate the need for herbicide.


Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 319 ◽  
Author(s):  
Laura Vincent-Caboud ◽  
Léa Vereecke ◽  
Erin Silva ◽  
Joséphine Peigné

Organic farming relies heavily on tillage for weed management, however, intensive soil disturbance can have detrimental impacts on soil quality. Cover crop-based rotational tillage (CCBRT), a practice that reduces the need for tillage and cultivation through the creation of cover crop mulches, has emerged as an alternative weed management practice in organic cropping systems. In this study, CCBRT systems using cereal rye and triticale grain species are evaluated with organic soybean directly seeded into a rolled cover crop. Cover crop biomass, weed biomass, and soybean yields were evaluated to assess the effects of cereal rye and winter triticale cover crops on weed suppression and yields. From 2016 to 2018, trials were conducted at six locations in Wisconsin, USA, and Southern France. While cover crop biomass did not differ among the cereal grain species tested, the use of cereal rye as the cover crop resulted in higher soybean yields (2.7 t ha−1 vs. 2.2 t ha−1) and greater weed suppression, both at soybean emergence (231 vs. 577 kg ha−1 of weed biomass) and just prior to soybean harvest (1178 vs. 1545 kg ha−1). On four out of six sites, cover crop biomass was lower than the reported optimal (<8000 kg ha−1) needed to suppress weeds throughout soybean season. Environmental conditions, in tandem with agronomic decisions (e.g., seeding dates, cultivar, planters, etc.), influenced the ability of the cover crop to suppress weeds regardless of the species used. In a changing climate, future research should focus on establishing flexible decision support tools based on multi-tactic cover crop management to ensure more consistent results with respect to cover crop growth, weed suppression, and crop yields.


Weed Science ◽  
2012 ◽  
Vol 60 (4) ◽  
pp. 624-633 ◽  
Author(s):  
Eric A. Nord ◽  
Matthew R. Ryan ◽  
William S. Curran ◽  
David A. Mortensen ◽  
Steven B. Mirsky

Knowledge of weed emergence periodicity can inform the timing and choice of weed management tactics. We tested the effects of weed management system (conventional [CNV] and herbicide-free [HF]), timing of rye sowing (two dates), timing of soybean planting (5 planting dates, 3 in each system), and supplemental control (with and without) on weed suppression and weed community composition in soybean no-till planted into a cereal rye cover crop. Cereal rye was terminated with a roller-crimper and herbicide (CNV) or with a roller-crimper alone (HF), and supplemental weed control was achieved with a postemergence glyphosate application (CNV) or with interrow high-residue cultivation (HF). Supplemental control with glyphosate in CNV was more effective than high-residue cultivation in HF. When soybean was planted on the same date, CNV resulted in less weed biomass and a more even community composition, whereas HF resulted in greater weed biomass, dominated by common ragweed. When we controlled for cereal rye biomass and compared the effects of cereal rye sowing and termination timing within each system, earlier management reduced weed biomass in HF, but tended to increase weed biomass in CNV. Our results suggest the ability to control emerged weeds prior to soybean planting is an important factor that influences the optimal cereal rye cover crop management timing for weed suppression.


2010 ◽  
Vol 24 (3) ◽  
pp. 253-261 ◽  
Author(s):  
Ruth A. Mischler ◽  
William S. Curran ◽  
Sjoerd W. Duiker ◽  
Jeffrey A. Hyde

Cover crop management with a roller/crimper might reduce the need for herbicide. Weed suppression from a rolled cereal rye cover crop was compared to no cover crop with and without postemergence herbicide application in no-till soybean. The experiment was designed as a two-way factorial with rye termination and soybean planting date as the first factor and weed control treatment as the second. Cereal rye was drill-seeded in late September and managed using glyphosate followed by a roller/crimper in the spring. Soybean was no-till seeded after rolling and glyphosate was applied postemergence about 6 wk after planting to half the plots. Rye biomass doubled when delaying rye kill by 10 to 20 d. Weed density and biomass were reduced by the rye cover crop in all site–location combinations except one, but delaying rye kill and soybean planting date only reduced both weed density and biomass at a single location. The cover crop mulch provided weed control similar to the postemergence herbicide in two of four locations. Treatments did not affect soybean grain yield in 2007. In 2008, yield at Landisville with rye alone was equal to those yields receiving the postemergence herbicide, whereas at Rock Springs, it was equivalent or less. The net added cost of a rye cover crop was $123 ha−1with or $68.50 ha−1without a postemergence herbicide application. A rolled-rye cover crop sometimes provided acceptable weed control, but weed control alone did not justify the use of the cover crop. The potential for reduced herbicide use and other ecosystem services provided by a cover crop justify further refinement and research in this area.


2012 ◽  
Vol 26 (3) ◽  
pp. 490-498 ◽  
Author(s):  
Andrew J. Price ◽  
Kip S. Balkcom ◽  
Leah M. Duzy ◽  
Jessica A. Kelton

Conservation agriculture (CA) practices are threatened by glyphosate-resistant Palmer amaranth. Integrated control practices including PRE herbicides and high-residue CA systems can decreaseAmaranthusemergence. Field experiments were conducted from autumn 2006 through crop harvest in 2009 at two sites in Alabama to evaluate the effect of integrated weed management practices onAmaranthuspopulation density and biomass, cotton yield, and economics in glyphosate-resistant cotton. Horizontal strips included four CA systems with three cereal rye cover crop seeding dates and a winter fallow (WF) CA system compared to a conventional tillage (CT) system. Additionally, vertical strips of four herbicide regimes consisted of: broadcast, banded, or no PRE applications ofS-metolachlor (1.12 kg ai ha−1) followed by (fb) glyphosate (1.12 kg ae ha−1) applied POST fb layby applications of diuron (1.12 kg ai ha−1) plus MSMA (2.24 kg ai ha−1) or the LAYBY application alone. Early-seasonAmaranthusdensity was reduced in high-residue CA in comparison to the CA WF systems in 2 of 3 yr.Amaranthusdensities in herbicide treatments that included a broadcast PRE application were lower at three of five sampling dates compared to banding early-season PRE applications; however, the differences were not significant during the late season and cotton yields were not affected by PRE placement. High-residue conservation tillage yields were 577 to 899 kg ha−1more than CT, except at one site in 1 yr when CT treatment yields were higher. CA utilizing high-residue cover crops increased net returns over CT by $100 ha−1or more 2 out of 3 yr at both locations. High-residue cover crop integration into a CA system reducedAmaranthusdensity and increased yield over WF systems; the inclusion of a broadcast PRE application can increase early-seasonAmaranthuscontrol and might provide additional control when glyphosate-resistantAmaranthuspopulations are present.


2018 ◽  
Vol 42 (4) ◽  
pp. 381-394 ◽  
Author(s):  
Aroldo Marochi ◽  
Antonio Ferreira ◽  
Hudson Kagueyama Takano ◽  
Rubem Silvério Oliveira Junior ◽  
Ramiro Fernando Lopez Ovejero

ABSTRACT Herbicide resistance has become a major concern for agricultural systems, and integrating weed management practices seem to be the most promise way for its mitigation. The effects of cropping systems including ruzigrass (Urochloa ruziziensis) associated with herbicide rotation programs were evaluated for the management of glyphosate resistant conyza (Conyza sumatrensis) and sourgrass (Digitaria insularis) in soybean and corn production systems. A 3x3 factorial was evaluated in four consecutive soybean (spring-summer) and corn (fall-winter) double cropping seasons. Factor A consisted of three combinations of cropping systems in the fall-winter: corn, corn plus ruzigrass, and ruzigrass alone. Factor B was based on increasing levels of diversity in herbicide mode of action over the four-year period (5, 8, and 11 MoAs). The results indicate that using ruzigrass significantly increased soil coverage by cover crop residues. In general, the cover crop was more efficient for conyza than for sourgrass control, whereas herbicide programs provided greater control on sourgrass than on conyza. Besides the weed suppression effect, the accumulation of ruzigrass biomass on the soil surface during the fall-winter also improved yield of soybean in the spring-summer. The integration of ruzigrass as a cover crop and the use of herbicide programs with multiple modes of action can provide efficient control of glyphosate-resistant conyza and sourgrass. The use of only one of these strategies was not effective in most cases, especially for the long term.


Author(s):  
H. S. Ravi Kumar ◽  
Udai Pratap Singh ◽  
Shiv Prakash Singh ◽  
Yashwant Singh ◽  
Uppu Sai Sravan

Declining productivity of rice-wheat system in Indo–Gangetic Plains poses risk to conventional practices because of high production cost and low input use efficiency. Four crop establishment methods (CEM) and four weed management practices (WMP) were compared in a 2–year study to determine the productivity and profitability of rice-wheat system. Growth, yield traits and yields of rice was uninfluenced by CEM. Zero tillage rice (ZTR)–zero tillage wheat (ZTW) exhibited highest improvement in mean wheat yield, system productivity and profitability by 7.5%, 4.0% and 16.0%, respectively over conventional tillage rice (CTR)–conventional tillage wheat (CTW). CTR–ZTW recorded minimum total weed density and biomass in system. Post emergence application of bispyribac 25 g ha-1 + azimsulfuron 35 g ha-1 (bis + azim) in rice at 20 days after sowing (DAS)/days after transplanting (DAT); clodinofop 60 g ha-1 + carfentrazone 20 g ha-1 (clod + carf) in wheat at 30–35 DAS minimized total weed density and biomass, increased growth, productivity and profitability of the system. Results suggest that higher growth, productivity and profitability of rice–wheat system may be achieved by adoption of ZTR–ZTW with application of bis + azim in rice and clod + carf in wheat.


2018 ◽  
Vol 16 (1) ◽  
pp. 31-40
Author(s):  
AKM Mominul Islam ◽  
Md Azhiat-Ul Huq Hia ◽  
Shubroto Kumar Sarkar ◽  
Md Parvez Anwar

Selection of appropriate weed management strategy helps reduce rice yield loss due to weeds. Despite some undesirable side-effects, no viable alternative is currently available to shift the chemical weed management in rice. However, time of herbicide application is very important with respect to its efficacy. Keeping in mind the inevitability of herbicidal weed control, the current study was designed to evaluate the response of selected aromatic fine rice varieties of Bangladesh to different herbicides based weed management practices compare to farmers’ practices. The experiment was conducted in a randomized complete block design with three replications. The experiment consisted of five aromatic rice varieties; Kalijira, BRRI dhan34, BRRI dhan37, BRRI dhan38 and Binadhan-13, and six different weed management practices comprising no weeding, weed free, mechanical + manual weeding, pre–emergence herbicide + manual weeding, post–emergence herbicide + manual weeding and pre– + post–emergence herbicide. Eleven weed species belonging to five families were observed in the experimental plots. Based on the summed dominance ratio (SDR), grassy weed species Echinochloa crusgalli (SDR of 30.7) was the most dominant species, whereas broadleaf weed Nymphaea nouchali (SDR of 0.83) was the least one. Among the weed control treatments, application of pre–+ post emergence herbicides offered the highest reduction in weed density and biomass at all sampling dates which resulted in minimum crop-weed competition facilitating improvement in the yield contributing characters and finally resulted in the highest grain yield (2.5 t ha−1) and harvest index (30.7%) next to the weed free treatment. The variety BRRI dhan38 gave the highest grain yield (3.4 t ha−1) due to the highest performance of the yield contributing characters among the varieties. In interaction, BRRI dhan38 with pre–+ post–emergence herbicide application gave the highest yield (3.4 t ha−1) apart from the weed free treatment. Being efficient in weed density and biomass reduction as well as the highest yield producer, sequential application of pre–and post–emergence herbicides may be recommended for effective weed management practices in BRRI dhan38J. Bangladesh Agril. Univ. 16(1): 31-40, April 2018


2007 ◽  
Vol 21 (4) ◽  
pp. 1039-1048 ◽  
Author(s):  
Danielle D. Treadwell ◽  
Nancy G. Creamer ◽  
Jonathan R. Schultheis ◽  
Greg D. Hoyt

A 3-yr field experiment was initiated in 2001 to evaluate weed suppression and sweetpotato productivity in three organic sweetpotato production systems. Organic systems were (1) compost and no cover crop with tillage (Org-NC), (2) compost and a cover crop mixture of hairy vetch and rye incorporated before transplanting (Org-CI), and (3) compost and the same cover crop mixture with reduced tillage (Org-RT). A conventional system with tillage and chemical controls (Conv) was included for comparison. Suppression of monocot and dicot weed density and biomass was similar between Org-NC and Org-CI each year, and were frequently similar to Conv. Org-RT was as effective as Org-NC in controlling dicot weed density and biomass each year, but did not suppress monocot weeds. At sweetpotato harvest, an increase in cover crop surface residue biomass in Org-RT was associated with a decrease in cumulative total weed density (R2= 0.43, P = 0.0001); however, the amount of that residue was insufficient to suppress late-emerging monocot weeds. Total sweetpotato yield in Org-RT was at least 45% lower than other systems in 2002 and was most likely due to an increase in monocot weed density and biomass concurrent with a decrease in sweetpotato vine biomass. Total sweetpotato yield was similar among all systems in 2001 and 2004; the exception was lowest yields obtained in the Org-RT system in 2002. Organically managed sweetpotato with or without an incorporated cover crop produced sweetpotato yields equal to conventionally managed systems despite difficulties controlling weeds that emerged later in the season.


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