Black point of wheat (Bipolaris sorokiniana (Sacc) Shoem. influenced by N fertilization under no till and conventional tillage

The aim of this paper was to study the behaviour of a wheat cultivar inoculated with Bipolaris sorokiniana under different tillage methods and nitrogen fertilization. In field inoculation tests the tillage methods used were: conventional tillage (CT) and no-till (NT) both under no-nitrogen (N0) and application of 90 kg N/ha (as urea) splitted half at sowing and half at the end of tillering (N1). Wheat heads were sprayed at anthesis with a conidial suspension of B. sorokiniana and covered with plastic bags. At ripeness, the ears were collected and handthreshed. The seeds were analyzed by the blotter test method, following the rules given by the International Seed Testing Association (ISTA). The presence of the fungus was confirmed by the development of a dark brown mycelium on the grains surface. A higher number of contaminated seeds with Bipolaris sorokiniana and a higher proportion of contaminated seeds no germinated were found under CT than NT, which could be related to differences in plant senescence.