The water use efficiency of different genotype maize hybrids was examined on calcareous chernozem soil in a long-term experiment in the Hajdúság region between 2012–2014. In the long-term experiment, increasing doses of fertilisation were applied (control, N=30 kg ha-1, P2O5=22.5 kg ha-1, K2O=26.5 kg ha-1 basic treatment, and doses 2, 3, 4 and 5 times as high) to test hybrids PR37M81 (FAO 360), PR37N01 (FAO 380), P9494 (FAO 390) and SY Afinity (FAO 470). Despite crop years with various water supply levels, the control yields of hybrids (non-fertilised) reached a rather high yield level (10.0–14.6 t ha-1, depending on crop year). As a result of fertilisation, the examined hybrids provided significant yield surplus (2.6–6.1 t ha-1) in all three years. The maximum yield of maize hybrids was between 13.2–18.6 t ha-1, depending on the given crop year. The specific water use efficiency of maize hybrids was mainly determined by the water supply level of the given crop year and their nutrient supply, but there were also differences between each genotype. In the control treatment, the WUE values ranged between 26.57–59.90 kg ha-1 mm-1, while they ranged between 34.37–76.65 kg ha-1 mm-1 in the Nopt+PK treatment, depending on the given crop year. The most favourable WUE value was observed in 2013, when the water stock of the chernozem soil was replenished by the rainfall of the autumn and winter months. The WUE values of the older maize genotype (PR37M81) was surpassed by that of newer hybrids (PR37N01, P9494, SY Afinity), as they had more favourable results in different crop years and nutrient supply levels.

Keywords: maize, genotype, fertilisation, specific water use efficiency