Bulvių augimo sąlygų ir veislės įtaka derliui ir jo kokybei / | Potato tuber yield and quality as affected by growing conditions and varietal peculiarities.

Research on the effects of different fertilizers on potato yield, starch and dry matter content was carried out at the Lithuanian Institute of Agriculture’s Elmininkai Research Station during the period 2000-2002. Five Lithuania-registered potato varieties of different maturity groups were grown in the fields with different fertilization background: early ‘Goda’ and ‘Vokė’, medium early ‘Lady Rosetta’, medium late ‘Saturna’ and ‘Hermes’. Experimental evidence suggests that potato tuber yield was affected by different fertilizers applied, as well as by the varietal characteristics and the weather conditions during the potato growing season. According to three-years’ averaged data, most productive were found to be medium-late ‘Hermes’ (21.8-27.4 t ha-1). The highest yields of all potato varieties (19.3-36.0 t ha-1) were harvested in 2000. Using compound mineral fertilizers N90P90K180 and complex mineral fertilizers N90P90K180 with microelements, the highest yields (20.6-26.1 t ha-1 and 21.4-27.4 t ha-1) were harvested. Complex mineral fertilizers N90P90K180 with microelements were superior to compound mineral fertilizers N90P90K180 in terms of potato tuber yield. The weather conditions during the potato vegetative growth period and varietal characteristics had an impact on starch and dry matter content in potato tubers. The fertilizers used in the trial had no significant effect on these indicators. Three years’ averaged experimental findings indicate that the highest content of starch and dry matter was identified for the medium early variety ‘Lady Rosetta’ (17.0-17.9 % and 23.2-24.21 %) and the medium late variety ‘Saturna’ (17.1-17.4 % and 23.5-23.8 %). The highest starch and dry matter content in different potato varieties was found in 2002 (14.9-21.0 % and 21.3-27.1 %). Using manure (40 t ha-1), the highest starch and dry matter content (14.9-17.9 % and 21.2-24.2 %) was found in the tubers of most varieties studied.