Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Pratylenchus thornei associated with reduced wheat yield in Oregon.

Abstract

Field experiments were conducted in Oregon, USA, during 2003, to study the effect of Pratylenchus thornei on the yield of spring wheat cultivars Krichauff and Machete, with different levels of tolerance and susceptibility to P. thornei. The cultivars were treated or not treated with aldicarb. Grain yield was inversely correlated with pre-plant populations of P. thornei in soil and with P. thornei density in mature roots. As P. thornei populations increased, yield of the moderately tolerant/moderately susceptible Krichauff was generally more stable than for the intolerant/susceptible Machete. The reproductive factor (Pf/Pi) was generally lower for Krichauff than Machete. Aldicarb improved wheat yield in highly infested fields by an average of 67% for Krichauff and 113% for Machete. Aldicarb increased numbers of headed tillers, plant height and grain test weight and kernel weight, and reduced the density of P. thornei in mature wheat roots, variability in height of heads and leaf canopy temperature. Aldicarb did not improve yield in a soil with a low P. thornei population. This is the first report that P. thornei causes economic damage to wheat in the Pacific Northwest.