Crop mineral nutrient and yield responses to aphids or barley yellow dwarf virus in spring wheat and oat

Root system biomass reductions caused by aphid feeding or aphid-transmitted viral disease may affect root system function in spring wheat (Triticum aestivum L.) or oat (Avena sativa L.). A 2-yr field experiment was conducted to determine how leaf mineral nutrients (N, P, K, Ca, Mg, Zn, Fe, Mn, and Cu), chlorophyll (chl), and agronomic traits (leaf area index [LAI], leaf area plant(-1), midday differential canopy temperature deviation from control [dT], yield, and yield components) responded to crop stress imposed by aphid feeding (greenbugs [GB], Schizaphis graminum Rondani; Russian wheat aphids [RWA], Diuraphis noxia Mordvilko; bird cherry-oat aphids [BCOA], Rhopalosiphum padi L.) or by an aphid-vectored virus (barley yellow dwarf virus, Luteovirus, PAV strain [BYDV]). Leaf chl, N, Ca, and Mg concentrations (measured at the boot development stage) were about 25% less in BYDV-infected than control treatments. Grain yield deviation from control (dY) was most negative for BYDV treatment (-2164.5 kg ha(-1)) and least negative for GB treatment (-745.5 kg ha(-1)), with RWA (-900.6 kg ha(-1)) and BCOA (-789 kg ha(-1)) treatments having intermediate effects. Mineral nutrients (N, K, Mg, and Mn) and chi were significantly correlated (Canonical r = 0.94, p < 0.0001) with agronomic traits (LAI, dT, leaf area, and grain yield), and explained 62.1% of the variation in agronomic traits. Thus, leaf concentrations of certain chemical constituents of cereal plants are highly correlative to agronomic traits important in cereal plant responses to stress caused by aphid-feeding damage or aphid-vectored disease.