compost with phytophthora

[Itoero]

I'm pretty sure there is phytophthora in my self made compost.
Is it safe to use it for plants, other then tomatoes and patatoes?

[rainbowgardener]

Honestly, phytophthora is pretty much ubiquitous in soils. So I wouldn't worry too much about it being in your compost, because it is likely in all your soil and all of mine. Sometimes known as water molds, the phytophthora organisms require plenty of moisture. If you keep very well drained soil and let everything dry out a bit between waterings, the water molds will not thrive or be damaging.

[imafan26]

Proper composting should actually help sanitize and kill phythophthora fungi. There are many species of phythophthora that infest and cause crown and root rots on herbaceous and woody plants.

Root rot occurs when the soil around the root zone remains wet for prolonged periods. Phytophthora damage can be minimized by providing good soil drainage, raised beds or mounds in poorly drained soils, and selecting the most tolerant rootstocks or varieties available. Watering should be managed to make sure the plants get enough water without keeping the soil wet for prolonged periods of time. Avoid planting susceptible plants in areas of known phythophthora infestations.

In general, Phytophthora requires warm, moist soils in order to cause disease.

http://nature.berkeley.edu/garbelotto/d ... osting.pdf

[rainbowgardener]

I agree with everything imafan said. But just because I am a total nerd/ garden geek, I find it interesting that phytophthora is not actually a fungus (though it used to be considered such in the past). It is one of those fascinating creatures that is neither plant nor animal nor fungus, but its own kind of thing:

Phytophthora is a genus of the Oomycetes (water molds) which, through convergent evolution, have similarities to fungi. However, oomycetes are not fungi (as had been earlier thought), but are part of Stramenopiles, a kingdom distinct from plants, fungi, and animals that also includes diatoms and golden-brown and brown algae, such as kelp.
http://genome.jgi-psf.org/Physo1_1/Physo1_1.home.html

Who wooda thunk it? The phytophthora organism is closer related to kelp than to the fungi it resembles!

Ain't nature grand!?

[imafan26]

Thanks for the info, I did not know it wasn't a fungus.

[Itoero]

Ok, thanks for the info

This was the first year I had a kitchen garden and in the last month I had phytophtora in and outside the greenhouse, on my tomatoes.

Where I live (Belgium), they call phytophtora potatodisease.
Tomatos and potatos are sensitive for it, most other plants are not.
Is it the same in the USA?

[imafan26]

I think it was what caused the great potato famine in Ireland and the influx of Irish imigrants into the US. between 1845-1852. It is also called potato blight and can infect other member of the same family including tomatoes. It was caused by phythopththora infestans. There are other species of phythophtora that cause other root rots in many plants.

I have phythophthora in the herb garden where I volunteer because the soil there stays wet for very long periods of time and floods in a heavy rain for weeks. I know exactly the kind of problems you are running into. Unfortunately phythophthora will hang around for years and unless the underlying drainage problem can be resolved it is best to plant in raised beds or planters off the ground, redirect flood water if you can, and manage water carefully.

[rainbowgardener]

Yeah it's good news/ bad news:

Good news: phytophthora species are quite plant specific. So if you had one that was causing root rot in your tomatoes, it likely will not cause any problem if you plant melons there next.

Bad news: there are a zillion different phytophthora species!

[Itoero]

Where I live, spring and summer have many sunny days, sometimes the sunny weater lasts foàr several weeks.
In april 2013 we had only 2 days of rain.
But in september and oktober it starts to cool down and rain, with several thunderstorms.
Like now, it's raining and the wind is blowing like hell.

In september phytophtora starts to grow on tomatoes and patatoes.

[imafan26]

Funny, I get phythophthora problems mostly in summer. I thought it was because as long as it was raining intermittently it kept washing the phythophthora away and keeping the total numbers down. I do get plants yellowing around this time of year from continuous rains that don't allow the saturated ground to dry. But the deaths I get from phythophthora usually look a little different.

The phythophthora I get usually hits in midsummer when it hasn't rained for a while or only lightly. The temperature will not be especially hot, but the humidity will be high. Unfortunately 80% humidity is the norm here. A healthy 3-4 ft pepper plant will suddenly wilt and die in a week.

The plants that yellow from the winter rains can sometimes recover if the rains stop in time and they have a chance to dry out.

I found this article on how to tell the different diseases apart.

http://solutionsforyourlife.ufl.edu/hot ... seases.pdf