scholarly journals Effects of Red Clover Living Mulch on Arthropod Herbivores and Natural Enemies, and Cucumber Yield

2018 ◽  
Vol 112 (4) ◽  
pp. 356-364 ◽  
Author(s):  
Hanna M Kahl ◽  
Alan W Leslie ◽  
Cerruti R R Hooks

Abstract Increasing habitat complexity through cover cropping has been proposed as a tactic to reduce herbivore colonization and encourage natural enemies in cropping systems. To test the supposition that cover crops can be used to alter arthropod communities, we compared arthropod communities on cucumber (Cucumis sativus L.; Cucurbitaceae) interplanted with a red clover (Trifolium pratense L.; Fabaceae) living mulch and grown as a monoculture. In 2016 and 2017, visual surveys and yellow sticky card traps were used to estimate numbers of arthropod natural enemies and herbivores in each treatment. Among herbivores, striped cucumber beetles [Acalymma vittatum (Fabricius, 1775); Coleoptera: Chrysomelidae] and melon aphids (Aphis gossypii Glover, 1877; Hemiptera: Aphididae) had lower densities in the presence of red clover. However, populations of spotted cucumber beetle (Diabrotica undecimpunctata howardi Barber, 1947; Coleoptera: Chrysomelidae) had a variable response to red clover. Sticky card captures of natural enemies, including bigeyed bugs (Geocoris spp. Fallén; Hemiptera: Geocoridae), minute pirate bugs (Orius spp. Wolff; Hemiptera: Anthocoridae), and lady beetles (Coleoptera: Coccinellidae), were generally greater in cucumber interplanted with red clover than monoculture. Overall, cucumber yield did not differ between treatments. Findings from this study lend support to the hypothesis that greater habitat complexity can reduce herbivore densities.

2021 ◽  
pp. 1-28
Author(s):  
Nicholas T. Basinger ◽  
Nicholas S. Hill

Abstract With the increasing focus on herbicide-resistant weeds and the lack of introduction of new modes of action, many producers have turned to annual cover crops as a tool for reducing weed populations. Recent studies have suggested that perennial cover crops such as white clover could be used as living mulch. However, white clover is slow to establish and is susceptible to competition from winter weeds. Therefore, the objective of this study was to determine clover tolerance and weed control in established stands of white clover to several herbicides. Studies were conducted in the fall and winter of 2018 to 2019 and 2019 to 2020 at the J. Phil Campbell Research and Education Center in Watkinsville, GA, and the Southeast Georgia Research and Education Center in Midville, GA. POST applications of imazethapyr, bentazon, or flumetsulam at low and high rates, or in combination with 2,4-D and 2,4-DB, were applied when clover reached 2 to 3 trifoliate stage. Six weeks after the initial POST application, a sequential application of bentazon and flumetsulam individually, and combinations of 2,4-D, 2,4-DB, and flumetsulam were applied over designated plots. Clover biomass was similar across all treatments except where it was reduced by sequential applications of 2,4-D + 2,4-DB + flumetsulam in the 2019 to 2020 season indicating that most treatments were safe for use on establishing living mulch clover. A single application of flumetsulam at the low rate or a single application of 2,4-D + 2,4-DB provided the greatest control of all weed species while minimizing clover injury when compared to the non-treated check. These herbicide options allow for control of problematic winter weeds during clover establishment, maximizing clover biomass and limiting canopy gaps that would allow for summer weed emergence.


2021 ◽  
Vol 5 ◽  
Author(s):  
Zhaoke Dong ◽  
Mengjing Xia ◽  
Cheng Li ◽  
Baofeng Mu ◽  
Zhiyong Zhang

Sowing plants that provide food resources in orchards is a potential habitat management practice for enhancing biological control. Flowering plants (providing pollen and nectar) and grasses (providing alternative prey) can benefit natural enemies in orchards; however, little is known about their relative importance. We studied the effect of management practices (flower strips, grass strips, and spontaneous grass) on arthropod predators under organic apple management regimes in apple orchards in Beijing, China. Orchards located at two different sites were assessed for 3 years (2017–2019). The cover crops had a significant impact on the abundance and diversity of arthropod predators. The grass treatment consistently supported significantly greater densities of alternative prey resources for predators, and predators were more abundant in the grass than in the other treatments. The Shannon–Wiener diversity was significantly higher for the cover crop treatment than for the control. Community structure was somewhat similar between the grass and control, but it differed between the flower treatment and grass/control. Weak evidence for an increase in mobile predators (ladybirds and lacewings) in the orchard canopy was found. Ladybirds and lacewings were more abundant in the grass treatment than in the other treatments in 2019 only, while the aphid abundance in the grass treatment was lowest. The fact that grass strips promoted higher predator abundance and stronger aphid suppression in comparison to the flower strips suggests that providing alternative prey for predators has great biocontrol service potential. The selection of cover crops and necessary management for conserving natural enemies in orchards are discussed in this paper.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 840 ◽  
Author(s):  
Ahmed Laamrani ◽  
Paul R. Voroney ◽  
Aaron A. Berg ◽  
Adam W. Gillespie ◽  
Michael March ◽  
...  

The impacts of tillage practices and crop rotations are fundamental factors influencing changes in the soil carbon, and thus the sustainability of agricultural systems. The objective of this study was to compare soil carbon status and temporal changes in topsoil from different 4 year rotations and tillage treatments (i.e., no-till and conventional tillage). Rotation systems were primarily corn and soy-based and included cereal and alfalfa phases along with red clover cover crops. In 2018, soil samples were collected from a silty-loam topsoil (0–15 cm) from the 36 year long-term experiment site in southern Ontario, Canada. Total carbon (TC) contents of each sample were determined in the laboratory using combustion methods and comparisons were made between treatments using current and archived samples (i.e., 20 year and 9 year change, respectively) for selected crop rotations. Overall, TC concentrations were significantly higher for no-till compared with conventional tillage practices, regardless of the crop rotations employed. With regard to crop rotation, the highest TC concentrations were recorded in corn–corn–oats–barley (CCOB) rotations with red clover cover crop in both cereal phases. TC contents were, in descending order, found in corn–corn–alfalfa–alfalfa (CCAA), corn–corn–soybean–winter wheat (CCSW) with 1 year of seeded red clover, and corn–corn–corn–corn (CCCC). The lowest TC concentrations were observed in the corn–corn–soybean–soybean (CCSS) and corn–corn–oats–barley (CCOB) rotations without use of cover crops, and corn–corn–soybean–winter wheat (CCSW). We found that (i) crop rotation varieties that include two consecutive years of soybean had consistently lower TC concentrations compared with the remaining rotations; (ii) TC for all the investigated plots (no-till and/or tilled) increased over the 9 year and 20 year period; (iii) the no-tilled CCOB rotation with 2 years of cover crop showed the highest increase of TC content over the 20 year change period time; and (iv) interestingly, the no-till continuous corn (CCCC) rotation had higher TC than the soybean–soybean–corn–corn (SSCC) and corn–corn–soybean–winter wheat (CCSW). We concluded that conservation tillage (i.e., no-till) and incorporation of a cover crop into crop rotations had a positive effect in the accumulation of TC topsoil concentrations and could be suitable management practices to promote soil fertility and sustainability in our agricultural soils.


2009 ◽  
Vol 28 (8) ◽  
pp. 675-683 ◽  
Author(s):  
Nicole J. Bone ◽  
Linda J. Thomson ◽  
Peter M. Ridland ◽  
Peter Cole ◽  
Ary A. Hoffmann

2019 ◽  
Vol 33 (2) ◽  
pp. 296-302
Author(s):  
Victoria L. Stanton ◽  
Erin R. Haramoto

AbstractIntegrating multiple weed management (cultural, physical, chemical) strategies is often recommended to combat herbicide resistance. With the increased use of interseeded cover crops, the effects of PRE herbicides on their establishment and growth require study. An investigation was conducted in Lexington, KY, in 2016 through 2018 to assess the extent to which commonly used PRE corn herbicide combinations influenced interseeded red clover and annual ryegrass establishment and growth. Annual ryegrass density was reduced 29% at 3 wk after interseeding by the combination of residual dimethenamid-P and atrazine; however, biomass the following spring was not affected by herbicide combinations. Neither density of interseeded red clover at 2 to 3 wk after interseeding nor biomass prior to termination the following spring were influenced by herbicide combinations. However, red clover density was affected by herbicide treatment 5 wk after interseeding in 2016. These results could have been influenced by low summer survival, particularly in 2016. The environmental factors may have influenced the survival of the interseeded cover crops more than the PRE herbicides. This study suggests that multiple PRE herbicides can be used with minimal risk to interseeded red clover or annual ryegrass. However, the influence of the environment on establishment and survival of interseeded cover crops following the use of PRE herbicides requires further study.


2019 ◽  
Vol 19 (3) ◽  
Author(s):  
Mei Luo ◽  
Zinan Wang ◽  
Binjuan Yang ◽  
Lixia Zheng ◽  
Zhiwen Yao ◽  
...  

2019 ◽  
Vol 112 (4) ◽  
pp. 1587-1597 ◽  
Author(s):  
Juan Pedro Raul Bouvet ◽  
Alberto Urbaneja ◽  
César Monzó

Abstract The Spirea citrus aphid, Aphis spiraecola Patch, and the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are key pests of clementine mandarines in the Mediterranean basin. Severity of aphid infestations is determined by environmental variables, host plant phenology patterns, and the biological control exerted by their associated natural enemies. However, there is no information about the role these limiting and regulating factors play. Aphid densities, citrus phenology, and associated predators that overwinter in the crop were monitored weekly throughout two flush growth periods (February to July) in four clementine mandarin groves; relationships between these parameters and environmental variables (temperature and precipitation) were studied. Our results show exponential increase in aphid infestation levels to coincide with citrus phenological stages B3 and B4; shoots offer more space and nutritional resources for colony growth at these stages. Duration of these phenological stages, which was mediated by mean temperature, seems to importantly determine the severity of aphid infestations in the groves. Among those studied, the micro-coccinellids, mostly Scymnus species, were the only group of predators with the ability to efficiently regulate aphid populations. These natural enemies had the highest temporal and spatial demographic stability. Aphid regulation success was only achieved through early presence of natural enemies in the grove, at the aphid colonization phase. Our results suggest that conservation strategies aimed at preserving and enhancing Scymnus sp. populations may make an important contribution to the future success of the biological control of these key citrus pests.


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