Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/8/2013
Publication Date: 11/20/2013
Citation: Kandel, S.L., Smiley, R.W., Garland Campbell, K.A., Elling, A.A., Abatzoglou, J., Huggins, D.R., Rupp, R., Paulitz, T.C. 2013. Relationship between climatic factors and distribution of Pratylenchus spp. in the dryland wheat production areas of Eastern Washington. Plant Disease. 97:1448-1456. Interpretive Summary: Root lesion nematodes (Pratylenchus spp.) are major pathogens of cereals in the Inland dryland wheat production area of the Pacific Northwest. We conducted extensive surveys of wheat fields in 2010 and 2011, and quantified the populations of Pratylenchus spp. We correlated these distributions with climatic variables such as rainfall and temperature. . All precipitation variables were significantly positively correlated with nematode abundance. Summer maximum air temperature was negatively correlated and winter minimum air temperature was positively correlated with nematode densities. In addition, both years’ nematode densities were significantly correlated with cropping intensity. We developed models to describe these relationships.
Technical Abstract: Field surveys were conducted by collecting soil samples to estimate nematode densities in soil from winter wheat, spring wheat, spring barley, and spring legumes (lentil, chickpea, and pea) fields during 2010 and 2011. Pratylenchus spp. were observed in 60 percent of sampled fields. However, nematodes were detected in nearly all of the survey fields in high numbers where crops were grown every year. To identify climatic variables associated with density of Pratylenchus spp. in soil, correlation and regression analyses were performed using climate data of survey sites from 1979 to 2010. Fifty-seven climate variables were significantly correlated with densities of Pratylenchus spp. All precipitation variables were significantly positively correlated with nematode abundance. Summer maximum air temperature was negatively correlated and winter minimum air temperature was positively correlated with nematode densities. In addition, both years’ nematode densities were significantly correlated with cropping intensity. Five multivariate regression models for 2010 and seven models for 2011 nematode abundance levels were developed. The majority of the climate variables selected in the models were related to precipitation. Knowledge of root-lesion nematodes distribution in the dryland region of eastern Washington and associated climate variables may be helpful to determine risk and apply management practices to minimize crop damage.