Hi Thorn,
lsf is leaf spot fungus.If folk arent familiar with it it can be a right pain as you can be doing everything right and the plant is deteriorating before your eyes starting on the large fan leaves and gradually spreading but it doesnt usually kill the plant but does reduce yield,depending on how much the infection has spread.
In nature,fungi have an intimate relationship with many species of plants,some of which are harmful,others beneficial,and leaf spot fungus is a general term for various types of these harmful pathogens but the beneficial ones called v.a.m.s. or vesicular arbuscular myccorhiza's and trichoderma's can have a symbiotic relationship with a plant meaning the host plant acts as a home and in return it gets nourshment or protection from pathogenic fungi.
You could innoculate an acorn with a beneficial trichoderma and 600 years later at the top of the tree every leaf has an interconnected trichoderma network within it which prevents harmful fungi from entering.
The v.a.m.s can act as an interface between compost and root system and effectively help to feed the plant as they grow nodules along the root length which interact with the whole rhizosphere,which is your compost at the fungal level.
I sprayed 3 of my girls yesterday and I see others today are starting to be affected so will be spraying more and I'll get some more pics up of the worst affected leaves.
It's a right bitch is lsf but I've only myself to blame as I have beneficial trichoderma's but did'nt knock up a batch for treatment.(Rockster tries to kick own arse!)
The preparation is done by putting molasses in a bucket of water with the trichoderma powder and bubbling with an airstone overnight which activates the spores and the bucket is flowing over with foam come morning like an exploded washine machine!
The solution is then applied using a watering can with a coarse,not a fine rose on the end as the hyphae (little spikes that penetrate a leafs surface)will break off and become useless so they are never sprayed but dripped over a plant.
The spores attach to the leaf via the hyphae and then part of it enters the plant and starts to go through the plant tissues which innoculates it as then harmful fungi cannot enter.
There ya go,a few pics for Thorn.
Nasty eh?