Impact of Cover Crops on Insect Community Dynamics in Organic Farming

Abstract

Manipulating cover crops as an integrated pest management strategy has recently gained popularity in both traditional and organic agroecosystems. However, little information is available for producers to make informed decisions about cover crop selection, management, and their potential use as a pest management tool. To address this, we conducted a two-year, four-season field experiment on the potential of various cover crops during the summer seasons of both years, followed by monocultures of cash crops during winters. We hypothesized that the cover crop treatments would attract beneficial insects and repel damaging herbivores in a species-specific manner, and the insect community dynamics would be bridged to the cash crops in the subsequent season. In addition, we hypothesized that cash crops would suffer lower herbivory damage following specific cover crop treatments. Our design comprised of three cover crops. Our results indicate that cover crops support beneficial insects during the early summer season, while the time of growing season doesnot affect herbivore abundance. Crop-specific effects were found for herbivore abundance with possible cascading effects on insect community as well as damage levels on the subsequent cash crop, but without any impact on the growth traits of the cash crop. Together, our data suggest that cover crops, when carefully selected, can be an integral part of a pest management strategy for sustainable agriculture.

Can the introduction of companion plants increase biological control services of key pests in organic squash?

“…Previous studies have demonstrated that cowpeas alone or intercropped with marigolds are susceptible to severe infestations by A. craccivora and other insect pests (Tanga & Niba, 2019). Martinez et al (2020) also demonstrated the effect of cowpeas on insect pests when used as cover crop before squash planting. Authors showed that squash grown after cowpea cover crops suffered significantly higher pest damage compared with squash grown after other evaluated cover crops.…”

Dolichopodidae abundance in different cover crop species

“…Thus, the management of these cover crops is an important tool for conservative biological control. Although, the relationship between cover crops and natural enemies is widely studied (DAMIEN et al, 2017;MARTINEZ et al, 2020), in Brazil this is the first report associated with the Dolichopodidae family.…”

“…In this regard, some studies have investigated different techniques for landscape preservation and manipulation of the community of natural enemies (HEIMPEL & MILLs, 2017;HAAN et al, 2019;GONZÁLEs et al, 2020;CLOYD et al, 2020). Among the techniques used, the sowing of plants that provide food resources (e.g., floral resources such as pollen and nectar, in addition to the presence of prey or alternative hosts) has been strongly recommended (BARBOsA, 1998;sNYDER, 2019;MARTINEZ et al, 2020).…”

Organic Cultivation and Deficit Irrigation Practices to Improve Chemical and Biological Activity of Mentha spicata Plants

“…It has also been shown that EO volatiles are well perceived by the antennae of adults. Since many of the compounds present in the blend have been reported to attract L. botrana adults, it may be suggested that this herb has the potential to assist in vineyard protection in two possible modes: (1) as a cover crop, where some of the volatiles constituents attract egg-laying females and encourage oviposition, while others contribute to egg and larval mortality, thus reducing infestation in grapevines, as has been reported for other Lepidoptera species [70] or (2) as an essential-oil-based product aiming to contribute to pest management. In the context of increasing the adoption of sustainable agricultural practices such as integrated pest management, organic cultivation, or deficit irrigation schemes, the use of other plant species (intercropping, side-cropping, etc.…”