‘Spiking’ with stubble reduces the risk of failures to warn with crown rot testing using PreDicta B® – 2013

Abstract

Key findings • PreDicta BR is a good technique for identifying the level of risk for crown rot (and other soil‑borne pathogens) prior to sowing. However, this requires a dedicated sampling strategy and IS NOT a simple add on to a soil nutrition test. • Soil cores should be targeted at the previous winter cereal rows; if evident;and any stubble fragments should be RETAINED. • Short pieces of stubble (1–2 from each PreDicta BR soil sampling location) from previous winter cereal crops and/ or grass weed residues can be added to the soil sample to enhance detection of the Fusarium spp. that cause crown rot. • ‘Spiking’ soil samples with stubble will reduce the likelihood of ‘failure to warn’ situations for crown rot but unfortunately will also increase the probability of false warnings.