Effects of tillage and fallow rotation on wireworm populations and damage to cereal grain crops in Montana

Abstract

AbstractWireworms, the soil‐dwelling larval stage of click beetles, are an increasing pest threat to the sustainable production of cereals, potato (Solanum tuberosum L.), and other crops. Producers believe that soil tillage and crop–fallow rotation can reduce the damage caused by wireworms. This study used four field plots maintained under the same regimen of tilling and no‐till management in combination with continuous cropping and alternating fallow systems for more than 17 yr at the Montana State University Central Agricultural Research Station near Moccasin, MT. Bait traps were used to monitor wireworm numbers in the soil during 2011, 2012, and 2013, along with stand density and yield assessments, to gain insights into the effectiveness of tillage and fallow cultural practices to reduce wireworm populations. Wireworm numbers were higher in continuously cropped plots than in those with an alternating crop and fallow rotation. No differences in wireworm numbers were detected when comparing tillage versus no‐tillage plots. Up to six different species of wireworm were identified within an individual field, and the diversity of their biology may influence the effectiveness of cultural practices.