How can cover crops contribute to weed management? A modelling approach illustrated with rye ( Secale cereale ) and Amaranthus tuberculatus

Enriching agroecosystems with non-crop vegetation is a popular strategy for conservation biocontrol. In vineyards, the effects of specific seeded or planted cover crops on natural enemies are well-studied, whereas conserving spontaneously developing weeds received less attention. We compared parasitoid communities between matched pairs of vineyard plots in northern Israel, differing in weed management practices: “herbicide”, repeated herbicide applications vs. “ground cover”, maintaining resident weeds and trimming them when needed. Using suction sampling, we assessed the parasitoids’ abundance, richness, and composition during three grape-growing seasons. Ground cover plots had greater parasitoid abundances and cumulative species richness than herbicide-treated plots, possibly because of their higher vegetation cover and richness. Dominant parasitoid species varied in their magnitude and direction of response to weed management. Their responses seem to combine tracking of host distributions with attraction to additional vegetation-provided resources. Parasitoid community composition was mildly yet significantly influenced by weed management, while season, year, and habitat (weeds vs. vine) had stronger effects. Vineyard weeds thus support local biocontrol agents and provide additional previously demonstrated benefits (e.g., soil conservation, lower agrochemical exposure) but might also attract some crop pests. When the benefits outweigh this risk, weed conservation seems a promising step towards more sustainable agricultural management.

Download Full-text

Spring-planted cover crops for weed control in soybean

Renewable Agriculture and Food Systems ◽

10.1017/s1742170521000107 ◽

2021 ◽

pp. 1-8

Author(s):

Katja Koehler-Cole ◽

Christopher A. Proctor ◽

Roger W. Elmore ◽

David A. Wedin

Keyword(s):

Weed Control ◽

Biomass Production ◽

Cover Crops ◽

Weed Management ◽

Block Design ◽

Weed Suppression ◽

Crop Species ◽

Cold Temperatures ◽

Weed Biomass ◽

Small Grains

Abstract Replacing tillage with cover crops (CC) for weed management in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems with mechanical weed control has many soil health benefits but in the western Corn Belt, CC establishment after harvest is hampered by cold temperatures, limited labor and few compatible CC species. Spring-planted CC may be an alternative, but information is lacking on suitable CC species. Our objective was to evaluate four spring-planted CC with respect to biomass production and weed suppression, concurrent with CC growth and post-termination. Cover crop species tested were oat (Avena sativa L.), barley (Hordeum vulgare L.), brown mustard [Brassica juncea (L.) Czern.] and yellow mustard (Brassica hirta Moench). They were compared to no-CC treatments that were either tilled pre- and post-planting of soybean (no-CC tilled) or not tilled at all (no-CC weedy). CC were planted in late March to early April, terminated 52–59 days later using an undercutter, and soybean was planted within a week. The experiment had a randomized complete block design with four replications and was repeated for 3 years. Mustards and small grains produced similar amounts of biomass (1.54 Mg ha−1) but mustard biomass production was more consistent (0.85–2.72 Mg ha−1) than that of the small grains (0.35–3.81 Mg ha−1). Relative to the no-CC weedy treatment, mustards suppressed concurrent weed biomass in two out of 3 years, by 31–97%, and small grains suppressed concurrent weed biomass in only 1 year, by 98%. Six weeks after soybean planting, small grains suppressed weed biomass in one out of 3 years, by 79% relative to the no-CC weedy treatment, but mustards did not provide significant weed suppression. The no-CC tilled treatment suppressed weeds each year relative to the no-CC weedy treatment, on average 87%. The ineffective weed control by CC reduced soybean biomass by about 50% six weeks after planting. While spring-planted CC have the potential for pre-plant weed control, they do not provide adequate early season weed suppression for soybean.

Download Full-text

Inter-row Cultivation Timing Effects on Waterhemp (Amaranthus tuberculatus) Control and Sugarbeet Yield and Quality

Weed Technology ◽

10.1017/wet.2021.10 ◽

2021 ◽

pp. 1-39

Author(s):

Nathan H. Haugrud ◽

Thomas J. Peters

Keyword(s):

Weed Management ◽

Field Experiments ◽

Leaf Tissue ◽

Sucrose Content ◽

Climate Data ◽

Crop Canopy ◽

Control Practice ◽

Amaranthus Tuberculatus ◽

Residual Herbicide ◽

Weed Emergence

Abstract The invasion of waterhemp into northern sugarbeet growing regions has prompted producers to re-integrate inter-row cultivation into weed management programs as no currently registered herbicides can control glyphosate-resistant waterhemp POST in crop. Inter-row cultivation was a common weed control practice in sugarbeet until the release of glyphosate-resistant sugarbeet cultivars in 2008 made the use of inter-row cultivation unnecessary. In the late 2010s, producers began again to use inter-row cultivation to remove weeds that glyphosate did not control, but producers need information on the effectiveness and safety of inter-row cultivation when used with soil residual herbicide programs. Efficacy and tolerance field experiments were conducted in Minnesota and North Dakota from 2017 to 2019. Results from the efficacy experiment demonstrated cultivation improved waterhemp control 11% and 12%, 14 and 28 DAT, respectively. Waterhemp response to cultivation was dependent on crop canopy and precipitation after cultivation. Cultivation had minimal effect on waterhemp density in three environments, but at one environment, near Galchutt, ND in 2019, waterhemp density increased 600% and 196%, 14 and 28 DAT, respectively. Climate data indicated Galchutt, ND in 2019 received 105 mm of precipitation in the 14 days following cultivation and had an open crop canopy which likely contributed to further weed emergence. Results from the tolerance experiment demonstrated root yield and recoverable sucrose were not affected by cultivation timing or number of cultivations. In one environment, cultivating reduced sucrose content by 0.8% regardless of date or cultivation number, but no differences were found in three environments. In-season cultivation can damage/destroy leaf tissue which is likely responsible for the reduction in sucrose content. Results indicate cultivation can be a valuable tool to control weeds that herbicide cannot, but excessive rainfall and open crop canopy following cultivation can create an environment conducive to further weed emergence.

Download Full-text

Labile carbon and other soil quality indicators in two tillage systems during transition to organic agriculture

Renewable Agriculture and Food Systems ◽

10.1017/s1742170511000147 ◽

2011 ◽

Vol 26 (4) ◽

pp. 342-353 ◽

Cited By ~ 21

Author(s):

David Bruce Lewis ◽

Jason P. Kaye ◽

Randa Jabbour ◽

Mary E. Barbercheck

Keyword(s):

Soil Quality ◽

Cover Crops ◽

Organic Agriculture ◽

Weed Management ◽

Cover Crop ◽

Transition Period ◽

Interactive Effects ◽

Labile Carbon ◽

Initial Field ◽

Soil Attributes

AbstractWeed management is one of the primary challenges for producers transitioning from conventional to organic agriculture. Tillage and the use of cover crops are two weed control tactics available to farmers transitioning to organic management, but little is known about their interactive effects on soil quality during the transition period. We investigated the response of soils to tillage and initial cover crop during the 3-year transition to organic in a cover crop–soybean (Glycine max)–maize (Zea mays) rotation in the Mid-Atlantic region of the USA. The tillage treatment contrasted full, inversion tillage with moldboard plowing (FT) versus reduced tillage with chisel plowing (RT). The cover crop treatment contrasted annual versus mostly perennial species during the first year of the rotation. The experiment was initiated twice (Start 1 and Start 2), in consecutive years in adjacent fields. By the end of the experiment, labile carbon, electrical conductivity, pH and soil moisture were all greater under RT than under FT in both starts. Soil organic matter and several other soil attributes were greater under RT than under FT in Start 1, but not in Start 2, perhaps owing to differences between starts in initial field conditions and realized weather. Soil attributes did not differ between the two cover crop treatments. Combining our soils results with agronomic and economic analyses on these plots suggests that using RT during the organic transition can increase soil quality without compromising yield and profitability.

Download Full-text

Influence of Weed Management Practices and Crop Rotation on Glyphosate-Resistant Horseweed (Conyza canadensis) Population Dynamics and Crop Yield-Years III and IV

Weed Science ◽

10.1614/ws-09-006.1 ◽

2009 ◽

Vol 57 (4) ◽

pp. 417-426 ◽

Cited By ~ 40

Author(s):

Vince M. Davis ◽

Kevin D. Gibson ◽

Thomas T. Bauman ◽

Stephen C. Weller ◽

William G. Johnson

Keyword(s):

Population Dynamics ◽

Crop Rotation ◽

Crop Yield ◽

Cover Crops ◽

Weed Management ◽

Management Practices ◽

Plant Density ◽

Crop Yields ◽

Management Systems ◽

No Till

Horseweed is an increasingly common and problematic weed in no-till soybean production in the eastern cornbelt due to the frequent occurrence of biotypes resistant to glyphosate. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual non-glyphosate herbicides, and preplant application timing on the population dynamics of glyphosate-resistant (GR) horseweed and crop yield. A field study was conducted from 2003 to 2007 in a no-till field located at a site that contained a moderate infestation of GR horseweed (approximately 1 plant m−2). The experiment was a split-plot design with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying in-field horseweed plant density, seedbank density, and crop yield. Horseweed densities were collected at the time of postemergence applications, 1 mo after postemergence (MAP) applications, and at the time of crop harvest or 4 MAP. Viable seedbank densities were also evaluated from soil samples collected in the fall following seed rain. Soybean–corn crop rotation reduced in-field and seedbank horseweed densities vs. continuous soybean in the third and fourth yr of this experiment. Preplant herbicides applied in the spring were more effective at reducing horseweed plant densities than when applied in the previous fall. Spring-applied, residual herbicide systems were the most effective at reducing season-long in-field horseweed densities and protecting crop yields since the growth habit of horseweed in this region is primarily as a summer annual. Management systems also influenced the GR and glyphosate-susceptible (GS) biotype population structure after 4 yr of management. The most dramatic shift was from the initial GR : GS ratio of 3 : 1 to a ratio of 1 : 6 after 4 yr of residual preplant herbicide use followed by non-glyphosate postemergence herbicides.

Download Full-text

Rye (Secale cereale L.) and Hairy Vetch (Vicia villosa Roth) Intercrop Management in Fresh-market Vegetables

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.121.3.586 ◽

1996 ◽

Vol 121 (3) ◽

pp. 586-591 ◽

Cited By ~ 6

Author(s):

Vasey N. Mwaja ◽

John B. Masiunas ◽

Catherine E. Eastman

Keyword(s):

Cover Crops ◽

Secale Cereale ◽

Diamondback Moth ◽

Cabbage Looper ◽

Growth And Yield ◽

Winter Rye ◽

Hairy Vetch ◽

Fresh Market ◽

Vicia Villosa ◽

Snap Bean

The effect of cover-crop management on growth and yield of `Bravo' cabbage (Brassica oleracea var. Capitata L.), `Market Pride' tomato (Lycopersicon esculentum Mill.), and `Mustang' snap bean (Phaseolus vulgaris L.) was determined. Each fall, `Wheeler' winter rye (Secale cereale L.) and `Oregon Crown' hairy vetch (Vicia villosa Roth) were interseeded. The following spring, the cover crops were killed by either applying glyphosate and mowing (CC-G) or mowing and disking (CC-D). Trifluralin was preplant incorporated into bare ground as a conventional tillage (CT) treatment. In 1992 and 1993, a chicken (Gallus gallus L.) based fertilizer was applied to half the subplots. The greatest snap bean and cabbage yields were in CT. The system with the greatest tomato yields varied. In 1991, the greatest tomato yields were in the CT treatment, while in 1992 yields were greatest in the CT and CC-D treatments, and in 1993 the greatest yields were in CT and CC-G. Cabbage yields were greater in the fertilized than the unfertilized treatments. In 1992, infestations of diamondback moth, imported cabbageworm, and cabbage looper were greater in CT than in the CC-G treatment. Three years of the CC-G treatment increased soil organic matter from 3.07% to 3.48% and increased soil pH from 6.30 to 6.51, while neither changed in the CT. Chemical names used: N-(phosphonomethyl) glycine (glyphosate); 2,6-dinitro-N,N-dipro`pyl-4-(trifluoromethyl) benzenamine (trifluralin).

Download Full-text

Integration of cover crops and fertilizer rates for weed management in celery

Weed Science ◽

10.1614/ws-05-078r.1 ◽

2006 ◽

Vol 54 (02) ◽

pp. 326-334 ◽

Cited By ~ 9

Author(s):

Kevin S. Charles ◽

Mathieu Ngouajio ◽

Darryl D. Warncke ◽

Kenneth L. Poff ◽

Mary K. Hausbeck

Keyword(s):

Soil Fertility ◽

Cover Crops ◽

Weed Management ◽

Weed Suppression ◽

Fertility Level ◽

Hairy Vetch ◽

Bare Ground ◽

Weed Biomass ◽

Cereal Rye ◽

Oilseed Radish

Field studies were carried out in Laingsburg, MI, from 2002 to 2004 on Houghton muck soil to assess the impacts of cover crops and soil fertility regimes on weed populations and celery yield. The cover crops were oilseed radish, cereal rye, hairy vetch, and a bare ground control. The fertility rates were full (180, 90, and 450 kg ha−1nitrogen [N], phosphorus pentoxide [P2O5], and potassium oxide [K2O], respectively), half (90, 45, and 225 kg ha−1N, P2O5, and K2O, respectively), and low (90 kg ha−1N). Each cover crop treatment was combined with the low or half rate of fertilizer. An additional treatment with bare ground plus the full rate of fertilizer was added as standard practice. Treatments were maintained in the same location for the duration of the study. Major weed species were common chickweed, prostrate pigweed, shepherd's-purse, common purslane, and yellow nutsedge. Each year, oilseed radish consistently produced the greatest biomass and provided over 98% early season weed biomass suppression. Hairy vetch and cereal rye provided about 70% weed suppression in early spring. Soil fertility level affected weed populations during the 2004 growing season. In 2004, weed biomass in treatments without cover crops or with vetch increased when greater amounts of fertilizer were applied. Within individual fertility levels, higher celery yields were recorded in the oilseed radish plots. For example, in the low fertility rate, celery yield was 34.8, 29.2, 23.9, and 24.4 ton ha−1in the oilseed radish, cereal rye, hairy vetch, and control plots, respectively in 2003. Overall, the results of this experiment indicate that when included in a system where hoeing and hand-weeding are the only weed control methods, cover crops can successfully improve weed management and celery yield on muck soils, allowing reduced fertilizer inputs.

Download Full-text

Strategies to terminate summer cover crops for weed management in no-tillage vegetable production in southeast Brazil

Weed Science ◽

10.1017/wsc.2021.58 ◽

2021 ◽

pp. 1-26

Author(s):

Roberto Botelho Ferraz Branco ◽

Fernando de Carvalho ◽

João Paulo de Oliveira ◽

Pedro Luis da Costa Alves

Keyword(s):

Pearl Millet ◽

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Weed Suppression ◽

No Tillage ◽

Weed Biomass ◽

Jack Bean ◽

Organic Mulch ◽

Sunn Hemp

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.

Download Full-text

Cover crops and weed management.

Non-chemical weed management: principles, concepts and technology ◽

10.1079/9781845932909.0049 ◽

2009 ◽

pp. 49-64 ◽

Cited By ~ 39

Author(s):

J. R. Teasdale ◽

L. O. Brandsæter ◽

A. Calegari ◽

F. Skora Neto

Keyword(s):

Cover Crops ◽

Weed Management

Download Full-text

Weeds, nitrogen and yield: measuring the effectiveness of an organic cover cropped vegetable no-till system

Renewable Agriculture and Food Systems ◽

10.1017/s1742170517000795 ◽

2018 ◽

Vol 34 (5) ◽

pp. 439-446 ◽

Cited By ~ 1

Author(s):

David Robb ◽

Geoff Zehnder ◽

Robin Kloot ◽

William Bridges ◽

Dara Park

Keyword(s):

Cover Crops ◽

Weed Management ◽

Field Experiments ◽

Soil Health ◽

Soil Disturbance ◽

Weed Suppression ◽

Vegetable Production ◽

Soil N ◽

No Till ◽

Mechanical Methods

AbstractOrganic vegetable growers rely heavily on mechanical methods such as tillage and other forms of labor-intensive soil cultivation for weed management despite the negative effects to soil health associated with intensive soil disturbance. The use of cover crops and no-till (NT) vegetable production represents an alternative approach to weed control that can enhance rather than degrade soil health; however, there are challenges inherent with this practice and previous results in vegetable production have been mixed. Field experiments were conducted over 2 yr at the Clemson Student Organic Farm to examine the effects of tillage [NT versus conventional tillage (CT)] on weed development and management in organic tomato and summer squash production under different nitrogen (N) fertility regimes, and to assess soil N dynamics in both systems. Squash yields were similar between tillage treatments in both years. NT tomato yields were 43% greater than CT yields in 2014, whereas CT tomato yields were 46% greater than NT yields in 2015. Squash and tomato yields per unit of management labor (time) were significantly greater in NT compared with CT treatments for both years. There were no statistical differences in squash and tomato yields between N fertilization treatments in either year. Pre- and post-season soil N results were mixed. Pre-season soil N levels were significantly higher in NT tomato plots in 2014 but similar between tillage treatments in tomato plots in 2015 and in squash plots both years. Post-season soil N levels in tomato plots were similar between tillage treatments both years. Post-season soil N levels were significantly higher in NT squash plots in 2014 and in CT squash plots in 2015. Roller-crimped NT mulches provided adequate early-season weed suppression in both years and saved considerable weed management and seedbed preparation labor. Overall, the results demonstrated that organic NT is a viable method for reduced tillage summer vegetable production in the southeastern Piedmont region.

Download Full-text