Four different winter wheat genotypes (GK Öthalom, Mv Ispán, Ingenio, Hyland) were examined in a long-term experiment on chernozem soil, following different previous crops (sweet maize, sunflower, grain maize) in 2018 and 2019. It was concluded that crop year, fertilisation and the previous crops significantly affected wheat yield. In 2018, the yield maximum of the different genotypes was 9.3 t ha-1 after sweet maize, 8.7 t ha-1 after sunflower, 8.8 t ha-1 after sweet maize, while in 2019, the respective maximum yields were 6.3 t ha-1, 6.9 t ha-1 and 6.4 t ha-1. The effect of previous crop was significant in the non-fertilised control treatment, while optimum fertilisation (Nopt+PK=150 kg ha-1+PK) could significantly reduce the unwanted effect of the previous crop, however, we could not eliminate the negative effects. Wheat yield was significantly affected by the photosynthetic capacity (LAI, SPAD readings and their dynamics) of the crop stands. In 2018, when weather was favourable, the obtained LAImax readings ranged between 4.0–8.5 m2m-2, while SPADmax readings ranged between 40.3–62.2, depending on fertilisation, genotype and previous crop. In 2019, when the weather was unfavourable, LAImax readings were between 1.8–3.9 m2m-2 and SPADmax ranged between 28.3–58.8. Using Pearson’s correlation analysis, a strong, significant correlation was shown between wheat yield and LAI readings (0.585xx–0.797xx), as well as between yield and SPAD readings (0.470xx–0.585xx). Wheat yield was affected by the variety (37%), fertilisation (25%) and the previous crop (also 25%) in the given ecological and agrotechnical system.

Keywords: winter wheat, yield, LAI, SPAD, correlation analysis