Domain: society (Horticulture and Plant Care)
Problem: I  was repotting my Pilea and was shocked to find this large white mass at the base of the roots. I poked it with tweezers and found it is not soft or squishy at all. It did not burst; instead, it feels quite hard and crusty like a dried-up scab. For context, I accidentally overwatered this plant severely about two months ago. It lost several leaves but eventually stabilized. Based on the image and this history, what exactly is this substance and do I need to apply any pesticides?
Answer: No pesticide needed. This is calloused or crustified root rot residue from the previous overwatering incident.