Nitrogen levels and their fractioning in gladiolus cultivation for Ferralitic Red soils

Resumo

The objective of this study was to evaluate growing nitrogen levels and application time of the nitrogen fertilizer in gladiolus cultivation. The experiment was carried out at Instituto de Investigaciones Hortículas Liliana Dimitrova (in the Municipality of Quivicán, La Habana, Cuba) in an Oxisol soil, from October to February of the 2004–2005 and 2005–2006 crop seasons. The quality components of the spikes and plant material were evaluated, as well as the effect of the treatments on the plant nutritional state and the shelf life of the spikes. No differences between nitrogen doses and fertilizer application time in quality variables of spikes and corms were observed. Nevertheless, with the variant 70 kg ha^-1 of N, one half applied in plantation and the other half applied 60 days later, a higher spike percentage of commercial categories and a lesser number of stems of inferior quality were obtained. As for the plantation nutritional state, there is a positive relation between the applied nitrogen levels and the foliar content of this element.