average tuber weight, titanium, tuber number per plant, tuber weight per plant, tuber yield, tuber yield structure
Abstract
The growing period for early potatoes is extremely short, only 50-80 days from planting to harvest. To obtain a high marketable tuber yield in such a short period good conditions for plant growth must be ensured. In modern agriculture, plant growth stimulants have been gaining increasing importance. Although titanium (Ti) is neither a major nor minor nutrient for plants, it is classified as a beneficial element for plant growth. This paper analyses the effect of dose (0.2 dm3*ha-1 or 0.4 dm3*ha-1) and date (leaf development stage – BBCH 14-16, tuber formation stage – BBCH 41-43, leaf development stage and tuber formation stage) of the application of Tytanit® (8.5 g Ti in 1 dm3) on the yield and yield components of very early-maturing potato cultivars (‘Lord’ and ‘Miłek’). Potatoes were harvested 75 days after planting (the end of June). Tytanit® caused an increase in the tuber number and tuber weight per plant, particularly under stress conditions, although the effect of cultivars was not consistent. The growth stimulant did not have any effect on the average tuber weight. Following the application of Tytanit®, the total tuber yield was higher, on average, by 2.26 t*ha-1 (7.5%), and the marketable tuber yield (diameter above 30 mm) by 1.88 t*ha-1 (6.4%). The tuber number per plant was higher when Tytanit® was applied at the dose of 0.2 dm3*ha-1. Potato plants produced greatest tubers when Tytanit® was only applied in the leaf development stage (BBCH 1416). With double Tytanit® applications, i.e. in the leaf development stage and with repeated treatment in the tuber formation stage, both the tuber number and tuber weight per plant were lower. The Tytanit® application contributed to improved marketable value of the early potato yield due to a decreased share of small tubers (diameter below 40 mm) and an increased share of large tubers (diameter above 51 mm) especially in a year with a periodical water shortage in the tuber growth period. The examined very early-maturing potato cultivars showed a differential response to Tytanit®. The growth stimulant had a greater effect on the tuber number and tuber weight per plant for the ‘Lord’ cultivar. Following the Tytanit® application, the total tuber yield of ‘Lord’ cultivar was higher, on average by 3.71 t*ha-1 (12.7%) and marketable tuber yield by 3.22 t*ha-1 (11.4%). Tytanit® caused an increase in tuber yield of ‘Miłek’ cultivar only in year with the highest air temperature and water shortage in June – the total tuber yield was higher, on average by 2.16 t*ha-1 (8.5%) and marketable tuber yield by 2.02 t*ha-1 (8.2%).
