EFFECT OF DRIP IRRIGATION AND COMPLEMENTARY NUTRITION WITH NITROGEN ON POTATO QUALITY AND YIELD.

A small-plot field experiment started in 2016 studied effect of drip irrigation on potato tuber yield and starch levels in the tubers. Two potato varieties with different vegetation periods (Monika, Jolana) were exposed to four drip irrigation intensity levels. They were non-irrigated controls and irrigated tubers with 60 %, 65 % and 70 % usable soil water capacity levels. The other studied parameter was represented by the effect of nitrogen fertilisation with the nitrogen nutrient added to the irrigation water (fertigation) in the course of the vegetation period in contrast to one-off application of the whole nitrogen dose before the potato planting. All irrigated variants in comparison to the non-irrigated controls showed 30-60 % yield increase. The effect of fertigation on yields was statistically insignificant. Starch levels in the tubers were mostly affected by the variety. The irrigated variants in comparison to the non-irrigated controls showed higher starch levels in the harvested tubers but the differences were statistically insignificant. [ABSTRACT FROM AUTHOR]