Nutter Budder

From what I can see, that knot already had a great development, if you have exerted force on an already structured knot, it is normal that it can break since the already developed and structured branches do not have as much flexibility as the new ones. Good Smokes😤😤😤

Hey, If you want to train your plant with strings try to put them higher on the branches,they are more flexible at the top,if you start pulling that low you could definitely snap them at the node Closer to the center the branches are stiffer,they need to be able to hold all those heavy buds in the end But if you need to train them that low you could try to supercrop them ✌️ happy growing

Possibly. Excess calcium can also cause brittle stems. Thin wire like in the picture would not be my first choice either..........in fact it would be my last choice.