After searching for years for a cure for root rot in papaya, I found a plant based mixture that kills the fungi and to some extend some nematodes. I guess this will work for citrus as well. It's not commercial, I grew the medicinal plants and mix it. I target mostly phytophthora and fusarium. Sure there are chemicals which work, but they remain in plants. SO i prefer something organic.
So this winter I will test on citrus.
Which citrus in your experience has the most root rot problems?