Beetle and maize yield response to plant residue application and manual weeding under two tillage systems in northern Zimbabwe uri icon

abstract

  • Surface-dwelling beetles are among some beneficial arthropods inhabiting agricultural fields, but they can be negatively affected by agricultural practices. In this study, we investigated the effects of plant residue application rates and weeding intensity on surface-dwelling beetle communities and maize yield under two tillage systems, using a long-term experiment at Chinhoyi University of Technology experimental farm, northern Zimbabwe. The experiment was established in December 2012 as a split-split plot in randomized complete blocks replicated three times, and data for our study were collected during two growing seasons (2013/14 and 2014/15). Beetle species such as Abacetus spp., Ancophthalmus oncotipes and Renatiella reticulata showed increased while Dromica limpompoipana had decreased abundances under no- relative to conventional tillage. Abundances of Zophosis boei decreased while those of Gonocephalum simplex, R. reticulata, Stenethmus tentyriniformis and Trachynotus reticulatus increased under plant residue application. During the third growing season of annual runs of the treatments, maize yield was least (4620 kg ha(-1)) in plots without plant residues and highest (10,978 kg ha(-1)) in plots treated with 8 t ha(-1) of plant residues. During the same growing season, maize grain yield was positively correlated with total abundance of beetles and those of R. reticulata, S. tentyriniformis and T. reticulatus. The effect of tillage system and weeding intensity on beetle abundance and maize grain yield under the environmental conditions of this specific study was minimal, but plant residue application promoted beetle species abundance while increasing maize grain yield.

publication date

  • 2019
  • 2019