Effect of different nitrogen levels on Septoria tritici development on three wheat cultivars

Abstract

The impact of plant mineral nutrition upon the vegetation pattern and plant architecture can. influence the pathogenic activities through the microclimate variability and thus can influence disease development. A study was carried out in green house to investigate the effect of five nitrogen regimes i.e. untreated control. 60 kg N ha-1. 120 kg N ha-1, 180 kg N ha-1, and 240 kg N ha-1, on the development of Septoria tritici on three winter wheat cultivars i.e. Riband, Hereward and Pastiche which are commonly grown in UK. The investigations revealed that disease development was related to the host tissue nitrogen content of the leaves. The aggregate of the three disease assessments from the flag and second leaf of the variety Riband showed that disease development increased with increased nitrogen application up to 180 kg N ha-1, beyond which disease was found to be lower than that recorded at nitrogen rates of 120 and 180 kg ha-1. The relationships between the tissue nitrogen contents and S. tritici infection found positive assessed both from flag and second fully expanded leaves. The variety Hereward showed a different response, with disease increasing up to 240 kg ha-1 nitrogen despite a reduction in leaf tissue nitrogen at 240 kg nitrogen application.