Effect of different drip irrigation regimes on tuber and starch yield of potatoes

Small-plot field trials monitored the effect of drip irrigation of potatoes on tuber and starch yield. The trials were performed at two different localities in two trial years, 2016 and 2017. The subject of the evaluation included two cultivars with different vegetation periods (the very early cv. Monika and the semi-early cv. Jolana). Four repeated trials studied 4 irrigation treatments according to the available water capacity (AWC) of the soil, i.e. without irrigation, irrigation when soil humidity decreased below 60, 65 and below 70% AWC. All monitored parameters reflected a positive effect of irrigation in comparison to the non-irrigated control. The Zabcice locality showed the highest tuber and starch yields mostly after medium-intensity irrigation. The Valecov locality achieved the highest tuber and starch yields after the highest-intensity irrigation. Subject to the locality and the cultivar, the recommendation is to introduce automatic irrigation start when the soil humidity drops to 65% AWC for heavy soils and 70% AWC for medium heavy soils.