Hello, Plant Pathologist here to help!

[Verinda]

Hello RandM, you are very welcome to the forum

[RandM]

What types of diseases are of concern for you where you live"

Have you any advice on what steps allotmenters could take to prevent spread of diseases to and between plots on a site?

Thanks

It would help to know what type of disease concerns you have in order to give you advice. Different diseases, different advice. I assume you are organic?

[muddyfeet]

Can you think of why my brassica seedlings die off when the get to the true leaf stage. Every time I sow cabbage, broccoli etc they do the same, they germinate fine usually 100% and then they wilt and die.
I sow them in trays in an unheated greenhouse and usually mist water them. Am I mollycoddling them? Should they be outside? Bottom watered?

Ideas would be appreciated.

[rustylady]

Can you think of why my brassica seedlings die off when the get to the true leaf stage. Every time I sow cabbage, broccoli etc they do the same, they germinate fine usually 100% and then they wilt and die.
I sow them in trays in an unheated greenhouse and usually mist water them. Am I mollycoddling them? Should they be outside? Bottom watered?

Ideas would be appreciated.

You're keeping them too wet, and it's not a good idea to mist water in an unheated greenhouse. Far better to water from the bottom, and only when they need watering.

[Nicos]

I assume you are organic?

Yes- many of us are

[zazen999]

I just joined to see if I could be of help to anyone. I am retired and have had experience with a variety of crops - potatoes, apples, pears, watermelons, and even cranberries (a little). I have worked with both fungal and bacterial diseases. So, I am at your disposal as needed. I don't have a blog on this topic, but I do have a profile page on HubPages, which I put in the trackback, where I have written on a variety of topics.

Are you in the UK?

[RandM]

Are you using new or pasteurized soil? If you are not, then you may be carrying the damping-off pathogens (Phytophthora or Pythium) within your soil mix. Misting isn't necessary either. Just water when the surface of the soil begins to dry, which may be several days between watering.

[RandM]

Yes- many of us are

Most of my research has been on finding organisms for biological control methods. However, when necessary (which is not often), I use other methods like cultural, plant resistance and chemical (as a last resort).

[RandM]

Are you in the UK?

No, I grew up and worked in the U.S. Now I live in Costa Rica, enjoying the tropical climate.

[zazen999]

Could you pop that into your location then please. Thanks.

[RandM]

Hello RandM, you are very welcome to the forum

Thank you Verinda!

[muddyfeet]

Are you using new or pasteurized soil? If you are not, then you may be carrying the damping-off pathogens (Phytophthora or Pythium) within your soil mix. Misting isn't necessary either. Just water when the surface of the soil begins to dry, which may be several days between watering.

I always use new multi-purpose compost. I think you and rustylady might be on the right track with the watering. I do tend to get over-enthusiastic with the watering.
Thanks for the input.

[Florence Fennel]

Hello and a very warm, if somewhat belated, welcome to the Vine

[RandM]

Could be useful ... are you coming from a chemical, organic or neutral position?

... and how does botrytis get into the greenhouse? I know it spreads rapidly between susceptible plants (in my case tomatoes), but how does it get there in the first place?

Botrytis spores are ubiquitous in nature, and they produce many spores very quickly. Wind dispersal helps them spread, and when in the greenhouse, water splashing helps them spread. If you could water your plants via a drip system, then you would probably have less disease incidence. Also, in my experience, controlling this is not very difficult with biological antagonists - if they are available where you live.

[RandM]

I always use new multi-purpose compost. I think you and rustylady might be on the right track with the watering. I do tend to get over-enthusiastic with the watering.
Thanks for the input.

Some people go to the trouble of pasteurizing, or cooking their soil or soil-compost, before using it for planting. One of my friends on HubPages has outlined the temperatures and times for doing this, and I thing you should try it out, in addition to watering less. Here is the link to her (The Dirt Farmer) article - Recipe for Organic Potting Soil Mix Since you are starting seeds with low volumes of soil in seed flats, this should be practical for you.