i had a chia lin that rotted where the bulb meets the roots. it turned black and leaf and all fell off. when i checked the roots, they were rotten. this happened very quickly.
i treated it with physan 20 twice when i first saw it and it didn't even slow it down. i had isolated it, too. how much trouble is my greenhouse in. i have had trouble with all the chia lins i have tried to grow.
no. i don't think so. i water once a week and i have 80 degree weather. the rest of my cats (about 50-60) are fine. i have been doing this for 20 years and have had virus and fungus, but never this. but i do appreciate your answering. it makes me think
I do not know how you have gone 20 years without seeing it before.
Pythion fungus is a constant fight. It exists everywhere and while healthy plants and good air circulation help prevent it, it can not totally be stopped. You will see black rot on the leaves spreading into the bulbs.
The only effective poisons are very expensive and very dangerous so I do not suggest them. It is actually illegal to sell them for home use.
Usually it starts on the leaf or where the leaf meets the pbulb. Once it gets into the bulb the plant is lost. If it is only on the leaf you can cut the leaf back to the bulb and save the plant.
It is slightly confusing since you said it started near the roots. It the bulb was more dark brown than black it would be fusarium fungus. Equally deadly and equally unavoidable. It exists everywhere and will be in bags of peat moss you buy for your gardens.
Nothing cures it. An infected plant should be removed from the pot and cut back until you have only good bulbs remaining. I just took a 12 inch basket with 10 flower buds down to 2 2" pots.
Fusarium is getting worst since over use of chemicals are developing drug resistant strains. Heritage is the newest chemical that works but not for home use, very dangerous and $585 a quart. And it will not kill the fungus only prevent it from starting on healthy plants.
Most fungi are water born I sterilize my feed water continuously using H2O2 and Sporekill. Prevention is better than cure. Once you have rot in amongst your plants it is going to infect your plants regularly So watch for it and treat it asap it can destroy a plant very quickly. I mostly cut the bad parts off and seal the cuts with sulphur Also when cutting of flower spikes make sure you seal the cut as well. I think up until you have been very lucky!!
Some Catts are more prone to rot than others so you might want to try mounting this one >
Good luck !!