Intercropping maize with brachiaria can be a double-edged sword strategy

BACKGROUND Intercropping is commonly implemented as a way of promoting sustainable agriculture. Some of the benefits of intercropping include improving resource-use efficiency and soil quality as well as promoting pest control. As for pest control, intercropping can often engender pest repellency/confusion and promote natural biological control. Nevertheless, intercropping is not always a win-win strategy for pest management, with chances of sometimes either favoring or hampering pests and their natural enemies. Brazilian farmers commonly row-intercrop maize with brachiaria with the intent of forming a grass pasture for the feeding of livestock after maize harvest. However, very little is known about whether this intercropping can influence key pests and natural enemies in the maize agroecosystem. The overall aim of this study was to investigate how multiple groups of maize pests and natural enemies respond in terms of temporal abundance to this intercropping. RESULTS Defoliation caused by caterpillars was higher in the intercropping treatment. Intercropping appeared to promote Dalbulus maidis while hampering aphids and Diabrotica speciosa. In general, the abundance of natural enemies was favored by intercropping. There was a reduction in maize productivity (i.e. fresh weight) in the intercropping treatment. Most results were season dependent. CONCLUSION We believe that by considering together the pros and cons of intercropping maize and brachiaria in terms of pest management and soil conservation/fertility, the benefits of implementing this intercropping shall still outweigh its potential challenges. Nevertheless, the results and ensuing recommendations should be considered under the context of time and arthropod species. (c) 2022 Society of Chemical Industry.

Automated summary

Intercropping maize with brachiaria can promote the abundance of pests and natural enemies in the maize agroecosystem. The intercropping treatment resulted in higher defoliation caused by caterpillars and increased populations of Dalbulus maidis, but reduced the populations of aphids and Diabrotica speciosa. Natural enemies were generally favored by intercropping. Maize productivity, however, was reduced in the intercropping treatment. The results and recommendations should be considered in the context of time and specific arthropod species.