Mycorrhiza and heavy rains question

[cdg]

Hello , I applied 0ne teaspoon of mycorrhiza to the planting hole in contact with the rootball when setting out my tomatoes in March. They have been doing very well , probably the best fruit set I can remember. Friday and Saturday we have had excess of 4 inches of rain. Today(Sunday) has been sunny -temps 85+ -and I believe all my plants are fine.
My question: Does the mycorrhiza wash off or dilute with the heavy rains and need to be applied again?? Probably a stupid question but I'm full of 'em.
CDGTXS

[mdvpc]

No stupid questions, so don't worry. Someone with more experience with myco will hopefully post, but I dont think so. I believe the myco attaches to the roots, but I may be wrong about that. If it does, it wont be washed away.

[kygreg]

I had the same question after 6 inches of rain here, but decided I wasn't going to dig the plant up to get to the root ball.

[bohica]

Great Question!
Mycorrhiza colonizes the plants' roots, the hyphae enter into the plant cells. Rain should not harm or wash away the Mycorrhiza.

[bigbubbacain]

Originally Posted by bohica

Great Question!
Mycorrhiza colonizes the plants' roots, the hyphae enter into the plant cells. Rain should not harm or wash away the Mycorrhiza.

I wonder if it's possible for the Mycorrhiza to colonize from one plant to the next? For example, if my innoculated tomatoes have enough in their rootzone to spread to the adjacent eggplant and onions? OR, do I simply need to innoculate everything?

[dice]

Sure, it can spread to different plants. One study (UCDavis if
I remember correctly) found that it overwintered on the roots
of many winter cover crops (vetch, clover, peas, cereal rye,
etc; not on mustard or oilseed radish), and then colonized
mycorrhizae-compatible vegetables planted into those same
beds the following year.

[jiminsrq]

Great questions and discussion. So far all correct.

[bigbubbacain]

Originally Posted by dice

Sure, it can spread to different plants. One study (UCDavis if
I remember correctly) found that it overwintered on the roots
of many winter cover crops (vetch, clover, peas, cereal rye,
etc; not on mustard or oilseed radish), and then colonized
mycorrhizae-compatible vegetables planted into those same
beds the following year.

Tell me, Dice:

Is it safe to say that I won't need to treat everything in a raised bed in which I've treated one group of vegetables, or should I treat everythinng to be safe?

[bohica]

You dont need to innoculate everything, but I normally do, a small pinch of a decent Mycorrhiza is all that you need.

[dice]

I would not guess that onions or garlic are colonized by
mycorrhizae, whether you add it or not. As for the rest,
I do not know how fast it grows. If I treat the rootball of
one tomato plant at one end of a 4' x 12' row, how long
does it take to reach the plants at the other end of the row?
I do not know. (It probably varies with the type of soil, the
weather, the specific type of mycorrhizae organism, etc.)

On the other hand, if it has been there all of the previous
summer from inoculated plants and all winter on the roots
of winter cover crops, it probably already exists throughout
the raised bed and will quickly colonize any new plants that
you plant there in the spring.

[cdg]

Thanks for all the replies. Now I'm wondering , will it overwinter in the soil without a cover crop??
CDG

[bohica]

Mycorrhiza has been reported to be able to live on Organic matter for long periods of time, and studies have shown that mycorrhiza can overwinter connected or detached from roots, there has been a 20%-30% decrease in live hyphea, I think that it is still worth broadcasting left over Mycorrhiza with your fall cover crops, we do this every fall.

[dice]

So, without the winter cover crop, likely to still be there but
reduced in extent by spring compared to the extent with a
winter cover crop that is mycorrhizae compatible.

Again, it depends a lot on your soil and weather. In a mineral soil
(sand, clay, etc), with little organic matter, there is simply
less food there to sustain mycorrhizae over the winter
without roots of live plants to grow on. If the soil freezes
solid a foot deep over the winter, that could make a serious
dent in the mycorrhizae population remaining in spring, too.
Harsh chemical treatments for fungal soil diseases
(fusarium, etc) in fall or spring could wipe it out, too.

[barkeater]

If your soil is healthy, i.e., 5% or more organic matter, buying expensive supplements that advertise mycorrhizae as an ingredient is an incredible waste of money. Just add compost annually and you'll always have all you'll ever need.

[bohica]

Barkeater, with all due respect, I think saying that it is an incredible waste of money is inaccurate, the amount found naturally in healthy soils and the amount applied by purchasing top quality Mycorrhiza is far different. If you are content with the results that you have, its a no brainer, but the improvements to the roots structure, the increased tolerance to drought, the increased uptake of nutrients and water are absolutely not an incredible wate of money in my opinion, not to mention that a healthy plant is far less susceptable to pests and disease.