MORPHOLOGICAL AND PHYSIOLOGICAL RESPONSES OF WINTER WHEAT SEEDLINGS TO NITROGEN AND PHOSPHORUS DEFICIENCY

Nitrogen (N) and phosphorus (P) deficiencies are major yield limiting factors in many parts of the world. A greenhouse experiment was conducted to study the effects of both N and P deficiency on morphological and physiological responses of wheat cultivars with and without purple coleoptiles in three types of soils. Before the 3-leaf stage, cultivar ‘Jagger’ with greenish coleoptile showed typical green color in leaves even if grown in soils known to be deficient in N and P. After 3-leaf stage, however, ‘Jagger’ grown in the same soils exhibited purple on leaves, which was considered a typical symptom of P deficiency. Before 3-leaf stage, cultivar ‘2174’ with purplish coleoptile showed purple on the tips of leaves even if grown in a soil not deficient in P, indicating that the leaf purple color is genetically controlled. Pre-plant P but not N fertilizer application could alleviate the purple severity of young seedlings (before 3 leaf stage). Top-dressing N fertilizer could alleviate the purple severity, bu...