My sunflower I have planted is starting to rot at the base of its stem, what is it and how can I stop it?

Question

My sunflower I have planted is starting to rot at the base of its stem, what is it and how can I stop it?

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Answer 1

This looks like pithium rot. Usually, once it has started it will only progress. Treatment is difficult, since you have to find the selective chemical for each type of root rot. Usually, information on the subject is geared toward prevention, which is the best method of control. This article will help: https://www.gardeningknowhow.com/plant-problems/disease/root-rot-in-garden-plants.htm