I've removed roses for more disease resistant roses throughout the years. But I've kept some roses which I've been spraying with Bayer disease control every 10 days to 2 weeks with great success.

However, this year it seems the day after I spray I see more black spot and yellowing on them. In particular yellowing leaves with Lyda rose.

With Lyda it's not that I see BS but her leaves were mostly green yesterday. After spraying I see today that they have yellowed to a considerable degree in comparison.

It seems spraying may be making things a bit worse.

Any ideas would be appreciated.