luvaduck
Active member
It seems a few of us Aussie outdoor growers have had issues with mould recently, so I thought I would start up a thread to get heads together, and maybe help reduce a most disheartening problem.
I'll begin with the problems I've encountered, my observations, and my conclusions. Keep in mind I grow in the wet tropics, where relative humidity can be in the high 90's for months on end. I would also like to point out that I don't like to use fungicides, or any chemical input for that matter, and very rarely do.
In seedlings, the most common issue I find is "damping off". In really bad cases, this can roll a seedling before the first set of true leaves appear. Seedlings generally appear sluggish and under nourished. Generally my issue has been waterlogged seed raising mix. I have also noticed an higher incidence if I don't sterilise my pots (I use 75mm tubes for germination). The brand of mix for me is important, I swear by searles as I never seem to have problems with that. Occasionally I will use my main potting mix (which I blend myself) as a base and then cover the seed with the finer seed raising mix.
The way I normally deal with damping off is to discard plants and potting medium, unless they are really important strains, in which case I will drench the soil with the recommended rate of mancozeb. I know this stuff is toxic, but I figure that this is the worst I use and it is normally in the first couple of weeks of growth, so little harm done? Worse walking down a city street and inhaling benzene..
During growth the only real fungal issue I have come across is root rot. In my situation this is due to soil type ie too heavy, sticky clay.. I find perlite to be a fantastic investment. It's cheap if you can find it in bulk, I normally pay $30 for 100 litres, and it is really light if you have to carry it long distances. That and coir fibre to amend native soils, just add ferts and, viola!
Flowering issues are the real let down. Nothing like running some real exciting strains then loosing a great percentage to rot. For me powdery mildew is not a great threat, although it does occur. The main issues I have are caused by rain and excessive humidity, and this brings on grey mould, cause by botrytis fungus. Fungicides are never really an option I go for here, although if I did I would use eco fungicide. It is potassium bicarbonate, which is a food grade product and about as mild as it comes. Any mould stuff I have goes to oil for the missus skin cancers.
Strain selection and plant health are the most important factors in my opinion. The right strain with mould resistance and a flowering time late enough to miss the wet weather has been the most important to me. In regards to plant health, ease up on the ferts, lush growth looks great but at the expense of soft plant tissue. I prep beds and do very little until harvest, except foliar spray with various products and ALWAYS include neem oil, until after the first month of flowering.
Hope you all have bumper crops. Please put your own 5 bobs worth, the more knowledge the better.
LD
I'll begin with the problems I've encountered, my observations, and my conclusions. Keep in mind I grow in the wet tropics, where relative humidity can be in the high 90's for months on end. I would also like to point out that I don't like to use fungicides, or any chemical input for that matter, and very rarely do.
In seedlings, the most common issue I find is "damping off". In really bad cases, this can roll a seedling before the first set of true leaves appear. Seedlings generally appear sluggish and under nourished. Generally my issue has been waterlogged seed raising mix. I have also noticed an higher incidence if I don't sterilise my pots (I use 75mm tubes for germination). The brand of mix for me is important, I swear by searles as I never seem to have problems with that. Occasionally I will use my main potting mix (which I blend myself) as a base and then cover the seed with the finer seed raising mix.
The way I normally deal with damping off is to discard plants and potting medium, unless they are really important strains, in which case I will drench the soil with the recommended rate of mancozeb. I know this stuff is toxic, but I figure that this is the worst I use and it is normally in the first couple of weeks of growth, so little harm done? Worse walking down a city street and inhaling benzene..
During growth the only real fungal issue I have come across is root rot. In my situation this is due to soil type ie too heavy, sticky clay.. I find perlite to be a fantastic investment. It's cheap if you can find it in bulk, I normally pay $30 for 100 litres, and it is really light if you have to carry it long distances. That and coir fibre to amend native soils, just add ferts and, viola!
Flowering issues are the real let down. Nothing like running some real exciting strains then loosing a great percentage to rot. For me powdery mildew is not a great threat, although it does occur. The main issues I have are caused by rain and excessive humidity, and this brings on grey mould, cause by botrytis fungus. Fungicides are never really an option I go for here, although if I did I would use eco fungicide. It is potassium bicarbonate, which is a food grade product and about as mild as it comes. Any mould stuff I have goes to oil for the missus skin cancers.
Strain selection and plant health are the most important factors in my opinion. The right strain with mould resistance and a flowering time late enough to miss the wet weather has been the most important to me. In regards to plant health, ease up on the ferts, lush growth looks great but at the expense of soft plant tissue. I prep beds and do very little until harvest, except foliar spray with various products and ALWAYS include neem oil, until after the first month of flowering.
Hope you all have bumper crops. Please put your own 5 bobs worth, the more knowledge the better.
LD
