Influence of mineral and organic nitrogen on tuber dry matter and specific gravity of potatoes

Dry matter percentage (DIv1%) is an important qualitative characteristic of potato tubers. Frequently N fertilisation significantly affects DM% but there have been several] studies differing in their results. According to Jenkins and Nelson (1992), numerous published reports indicate a reduction in DM%, others show no effects of N and some recorde instances where final DM% increases significantly as N rate increases. The DM% is normally estimated by the specific gravity (SG), despite some known limitations. The influence of mineral and organic N fertilising on dry matter content of the cv Desirée, the most important variety in Portugal, was studied during three years (1995-1997). For the last two years (1996-1997), specific gravity was also determined. The relationship between the specific gravity and the city matter content of tubers was established and analysed.

Influence of mineral and organic nitrogen on tuber dry matter and specific gravity of potatoes Artigo de Conferência