Cross-pollinating apple trees with different resistant varieties can affect the quality of the fruit they produce. In Hungary, researchers studied how pollinating apple trees like 'Rewena' and 'Baujade' with other resistant varieties influenced the size, sweetness, acidity, and firmness of the fruits. They found that different pollinizers led to significant differences in fruit characteristics. For example, 'Freedom' and 'Prima' resulted in larger and sweeter 'Rewena' apples, while 'Florina' produced flatter fruits. 'Reglindis' and 'Rajka' also had varying effects on the size and quality of 'Baujade' and 'Relinda' apples. The study shows that the type of pollen provider can impact the overall quality of the apples grown.