**4. Conclusions**

A detailed analysis of vegetative, generative and spectral properties of spelt and common wheat grown under zero and moderate N levels was carried out at Martonvásár, Hungary in three cropping seasons. Our results extend the findings of Caballero et al. [10] and highlight the fact that despite the lodging risk increasing together with N fertiliser level, spelt wheat is a real alternative to common wheat for low N input production both for low quality and fertile soils. Spelt may help promoting sustainable crop production at sites where low input managemen<sup>t</sup> is carried out because of any reasons by producing more yield than common wheat. Vitality indices such as flag leaf chlorophyll content and NDVI showed significant and moderate reaction to the increasing N fertiliser doses for common and spelt wheat. It was demonstrated that spelt wheat has considerably more moderate requirements compared to common wheat regarding soil nitrogen supply. Vitality indices were found to be good precursors of the final yield for both crops and the proposed estimation equations may improve the yield forecasting applications that use soil and/or weather parameters only by including crop-specific parameters that are already available around flowering.

**Author Contributions:** Conceptualization, T. Á., P.B. and E.S.; methodology, E.S. and G.V.; software, R.S.; validation, N.F., R.S. and E.S.; formal analysis, R.S. and N.F.; investigation, E.S. and P.B.; resources, G.V., P.B. and T. Á.; data curation, P.B.; writing—original draft preparation, E.S., R.S. and N.F.; writing—review and editing, E.S., R.S. and N.F.; visualization, R.S.; supervision, T. Á.; project administration, N.F.; funding acquisition, N.F.

**Funding:** This research was funded by the Széchenyi 2020 programme, and the European Regional Development Fund and the Hungarian Government, gran<sup>t</sup> number GINOP-2.3.3-15-2016-00028.

**Conflicts of Interest:** The authors declare no conflict of interest.

**Appendix A**


2016 80 3 4 0.46 0.56 44.6 47.2 5.77 5.13 0.32 0.37 5.24 4.76

**Table A1.** NDVI, SPAD value, LAImax (m2 m−2), Harvest Index and harvested grain yield (t ha−1), of spelt (*T. spelta*) and common wheat (*T. aestivum*) under four different nitrogen fertilization treatments (0, 40, 80 and 120 kgN ha−1) at Martonvásár (Hungary) in 2016, 2018 and 2019.







**Figure A1.** Harvest Index (HI) and NDVI of spelt (*T. spelta*) and common wheat (*T. aestivum*) across varieties under four different nitrogen fertilisation treatments (0, 40, 80 and 120 kgN ha−1) at Martonvásár (Hungary) in 2016, 2018 and 2019. \* indicates statistically significant difference between spelt and common wheat.
