Nitrate Effects on Growth of the First Four Main Stem Leaves of a Range of Temperate Cereals and Pasture Grasses

The effects of different applied NO3− concentrations on extension growth and final length and area of leaves 1–4 of five cereals and six pasture grasses of temperate origin were examined. Increased applied NO3− in the range 0.1–50 mol m−3; caused decreased duration of growth but increased growth rate and final length of leaves 2–4 of the cereals Avena saliva, Hordeum vulgare, Secale cereale × Triticosecale and Triticum aestivum. For all cereals, increased NO3− resulted in increased area of leaves 1-4. Pasture grasses were supplied either 0.5 or 50 mol m−3; NO3−. Increased applied NO3− (0.5–50 mol m−3) resulted in decreased duration of growth and increased growth rate and final area of leaves 1–4 of Bromus willdenowii leaves 2–4 of Festuca arundinaceae and leaves 3 and 4 of Lolium multiflorum. In addition, length of leaves 3 and 4 of B. willdenowii increased with increased NO3. Increased NO3 resulted in increased area of leaves 2–4 of Daciylis glomerata and Lolium perenne and leaves 3 and 4 of Phalaris aquatica but had no effect on extension growth of all three species.