Impact of weeding methods on the content of nitrates in potato tubers

The test results were based on a field experiment conducted in 2007-2009 in pilot plant of Plant Breeding and Acclimatization Institute – National Research Institute in Jadwisin on lessive soil with granulometric composition of loamy sand. The experiment was carried out applying the method of drawn sub-blocks in the dependent arrangement, split-plot, in three replications. Row I factors were the cultivars ‘Irga’ and ‘Fianna’, and row II factors were weed control methods: 1) control object – without chemical protection, 2) extensive mechanical treatments (every 2 weeks), carried out after planting until rows reached closeness, 3) Sencor 70 WG – 1 kg·ha-1 of pre-emergence potato, 4) Sencor 70 WG – 1 kg·ha-1 + Titus 25 WG – 40 g·ha-1 + Trend 90 EC – 0.1% of pre-emergence potato, 5) Sencor 70 WG – 0.5 kg·ha-1 of post-emergence potato, 6) Sencor 70 WG – 0.3 kg·ha-1 + Titus 25 WG – 30 g·ha-1 + Trend 90 EC – 0.1% of post-emergence potato, 7) Sencor 70 WG – 0.3 kg·ha-1 + Fusilade Forte 150 EC – 2 dm·ha-1 of post-emergence potato, 8) Sencor 70 WG – 0.3 kg·ha-1 + Apyros 75 WG – 26.5 g·ha-1 + Atpolan 80 SC – 1 dm·ha-1 of post-emergence potato. Harvest was performed at the technical maturity of the potato. Nitrate markings were performed according to the colorimetric method. The value of the trait was to a large extent determined by genetic factors. A medium-early variety ‘Irga’ had a higher nitrate content compared to an average late variety ‘Fianna’. Nitrate concentration in potato tubers was dependent on the applied weeding control methods used and atmospheric conditions in the research years. The tubers with the highest concentration of nitrates came from the facility where pre-emergence potato preparations Sencor 70 WG + Titus 25 WG + Trend 90 EC were used.