Leaf appearance, tillering and their coordination in response to NxP fertilization in barley

The aim of this work was to study the effects of nitrogen (N) and phosphorus (P) deficiencies and their interaction on the appearance of leaves and tillers of barley (Hordeum vulgare spp. distichum L.) by analyzing the rate and duration of the appearance period. Three microcrops experiments were carried out in 200 L containers using malting barley cv. Quilmes Palomar. Treatments were a factorial combination of two levels on N and two or three levels of P fertilization. Both N and P deficiencies delayed leaf and tiller appearance rates but leaf appearance was less susceptible to nutrient deficiencies than tiller appearance. P deficiency effects on leaf emergence differed from N effects. While N deficiency diminished the rate of leaf appearance (RLA), it has no significant effect on the duration of leaf appearance or on the duration of the period from emergence to flowering. On the other hand, P deficiency diminished RLA, and increased both the duration of leaf appearance and the duration of the period from emergence to flowering.