We searched for connections between weather conditions (with its sub-parameters as precipitation and average temperature) and the yearly formation of two quality parameters (protein content and baking value) on three levels of mineral fertilization, based on the results of a variety comparison experiment on chernozem soil, to select those weather parameters and critical periods which have significant effects on the quality of winter wheat flour.
We established that the protein content of winter wheat flour can be increased with increasing levels of mineral fertilizers. Protein content is lower and has higher deviation during non-fertilized conditions in different cropping years than on higher fertilization levels. Thus, it seems proved again that quality (as protein content) is mainly formed by the crop year, but can be improved with adequate agricultural engineering (with mineral fertilization in the present case). The higher sum of precipitation in May, and the lower average temperature after flowering, have the highest increasing effect on the protein content of flour of the examined parameters. Based on the results of the examined period, the rainier and warmer term than average before flowering and lower – average amount of precipitation and colder circumstances are favourable for higher baking values. The analysis with data of decades, proves the importance of the first half of May and the middle of June as especially important periods for quality formation. An increasing nutrient supply has different effects on the varieties; mineral fertilization increased the baking value of GK Öthalom winter wheat variety in almost every case, but the second level of fertilization decreased it in half of the examined years. Additionally, mineral fertilization played a role in the stabilization of the quality of highlighted varieties.