Influence of nitrogen fertilization on quality and storage of South Tyrolean seed potatoes

Abstract

Potato cultivation is of paramount importance for South Tyrol and represents especially for the agriculture in Pusteria valley an important source of income. The ‘Pustertaler Saatbau’cooperative stores and sells the majority of seed and regular potatoes grown in the province. The cooperative offers a selection of 25 different potato cultivars, carefully harvested and optimally stored until spring. Recently, premature germination has been observed on certain lots, possibly due to excessive nitrogen fertilisation. Therefore, a four-year trial (2016-2019) was carried out in collaboration with the Laimburg Research Centre to investigate the influence of different nitrogen (N) treatments on the storability of six different potato cultivars. In addition, two different methods for early prediction of excess use of N-fertilisation on potato lots were tested. Although in some years the over-fertilised potato cultivars were characterised by higher germination intensity during storage, our results showed that germination intensity is more likely to be influenced by a combination of factors, such as cultivar susceptibility, seasonality, weather and fertilisation. The potato cultivar selection, tailor-made cultivation practices and knowledge of their storability potential, enable the optimal marketing of this important source of income without facing unpleasant losses.