Field and greenhouse screening of oat seedlings for iron‐nutrition efficiency

Abstract Susceptible oat (Avena sativa L.) genotypes may express iron deficiency chlorosis when grown on calcareous soils. Known resistant ('Coker 227') and susceptible (TAM O‐312') cultivars were compared to 28 cultivars and breeding lines of oat in greenhouse and field plots. The soil used for both field and greenhouse studies was a Parrita sandy clay loam (Petrocalcic Paleustoll) with pH near 8.0. Previous research indicated that chlorosis expression was enhanced when seedlings were grown in saturated soils. Field plots were irrigated three times per week, while greenhouse seedlings were maintained in saturated soils after the 1.5 to 2‐leaf stage. Visual chlorosis scores were recorded in both field and greenhouse experiments. Individual seedlings were recovered from Super Cell Cone‐tainers when seedling were 3 to 4 week old, and data recorded on shoot and root length and dry weights. A root fibrousness score was also assigned. Root fibrousness was not highly related to chlorosis score (r = 0.25). Chlor...