Roots narrowed at base? root stunted

svengali

Member
I have a crop right now, my first grow, Snow white hybrid 80-20 S/I feminised (although partner has had a few in the past,) in a hydro system ebb and flow in it's 3rd week of flower cycle, all seemed well, until 2 plants withered and died, then another one went the same way, or at least I discovered a plant that had the same damage and was wilted also. These 3 plants had been quite small compared to the rest, after propagation i had 3 or 4 that were slow to start and were behind the main growth all the time, it might have been these ones, I should have kept track of what went where, next time i will.
Anyway, everything seemed ok, the lighting isn't quite right, so there have been some differences in height amongst the plants. The ones that have withered were a fair bit smaller, but seemed healthy enough other than that. Then 2 suddenly withered overnight. On closer inspection, the stem at the base where it goes into the media, a rockwool cube set in clay pebbles, the stem was very narrow for approx 25mm 1 inch, also there are a lot of little brown lumps, but I am told that is normal, and all plants in this species have these, sometimes I have seen them on cabbage stalks right enough, but thought I should mention it. Where the stem narrowed, the stem was a bit damp, and a bit slimy, there was no support left for the plant and it was only being propped up by a neighbouring plant. Now also, when the plant was removed the root ball was stunted, very small, like growth had stopped early on, but the roots weren't rotten, no smell, I thought it would be.

I have taken a few pictures, the first 2 are of the pulled plants, the 3rd and 4th ones are pics of the sem on a stock plant, it shows these bumps, and a slight narrowing of the stem as well. What is happening in these plants? Has it been a deformity during growth, which has then be attacked by pythium perhaps, as it is a secondary disease, usually there in most systems but preys on the sick plants.
I wondered also if it might be a case of boron deficiency? But that is a bit of a guess based on some info I picked up re Boron deficiency, but then wouldn't the rest of the crop been the same. I have some single plants also outwith the system, hand fed/watered, they too have the bumps, and their seems to be slight narrowing at the base of the stem here as well, but not bad, not as bad as the pulled ones and definitely not deteriorated and slimy.
Check the pics, and please tell me what has gone on with these plants if you can, maybe I could avoid it in the future. The roots at the back of the plant are not part of the pictured plant by the way, at the bottom of the frame of the first pic you will see the small plug of root riot media which is where the roots for this plant were found, and not much more!
I have drained the system and added the necessary hydrogen peroxide (Oxy) to the tank, also added 130ml of root regenerate (canadian express) hopefully this might help any pythium bacteria that has been circulated throughout the system. On advice from shop, I haven't reintroduced any nutes back in yet, but will do so gradually in 3 or 4 days. I hope the sudden stop of the nutes doesn't cause more problems. Any further advice welcome. Thanks a lot.
 

Attachments

Top