Foliar-applied Nitrogen Fertilizers in Spring Wheat Production

C admium (Cd) is a nonessential heavy metal that can cause kidney problems. Diet is the main source of Cd for nonsmokers, with cereal products, including pasta, accounting for up to 20% of the daily intake of Cd. The current official standard for maximum level of Cd in durum wheat grain as stated by the Codex Alimentarius Commission is 0.2 ppm. The European Union has adopted this level as the maximum allowed in domestic and imported durum, and may lower their accepted level to 0.15ppm. Other durum buyers may also adopt this level. Cadmium is found naturally in some soils, and is a contaminant of some phosphorus fertilizers. Durum grown on soil with lower pH takes up more Cd than durum grown on soil with higher pH. Higher soil salinity as measured by chloride content can also cause increased Cd uptake. Accumulation of Cd in durum grain is caused by a single recessive gene. By chance, most durum genotypes grown in Montana accumulate Cd in the grain. Breeding programs in the United States and Canada are developing durum varieties with the low Cd accumulation trait, but until those varieties are readily available, management practices that reduce Cd in durum grain will be useful to durum producers to make their crop more attractive Continued on page 2