Fusarium wilt
I mentioned in an earlier post that the Legend plant I cut down appeared to have fusarium wilt. This is not a good thing to have, as it affects all sorts of plants and can survive in the soil for years. I've no idea where it came from, as I've not had these symptoms before. The advice for people who have it is "grow resistant varieties".
Anyway, the Roma plant next door to the Legend also had it, and I removed this over the weekend (Roma is supposed to be resistant). I also decided to remove the Ferline plant which was dying having collapsed due to the weight of the fruit (I thought). Ferline is supposed to be resistant to fusarium wilt. This is what the stem looked like when I cut it off:
Its not easy to make out, but once you identify the cut off stem near the bottom of the photo, you can clearly see the brown areas in the xylem vessels which are charactaristic of this disease.
This is what a diseased plant looks like (also Ferline):
The plant in the middle (which was to the right of the one I just cut down) is dying from the bottom up, and has wilted in the hot sun. Unlike when the leaves die back naturally, wiggling them does not easily detach them at the leaf base, which is unusual - they remain firmly attached even when looking quite dead. The Mountain Magic (resistant to fusarium wilt) on its right is also beginning to look unhappy, but strangely the plant on the left (Ferline), which was next to the one I cut down, is ok apart from wilting a little in the heat (its 27C here today).
I think the important lesson here is the reminder that when a variety is described as "resistant" this is not the same as "immune". These varieties can still get the disease.
So, what's to do about this? Well, apparently the green manure Caliente Mustard, if grown then chopped or crushed and dug into the soil, will "fumigate" it with isothiocyanates - these are the chemicals that give things like mustard, nasturtiums and horseradish their taste. These apparently kill things like fusarium and verticillium wilt and also onion white rot (which I don't have as far as I know) - all these are fungal pathogens.
I have ordered a packet of Caliente mustard seeds (available from Marshalls) which can be sown now, and I will no doubt find out if it works next time I grow tomatoes in that area (which will be soon as it is one of the few areas that is sunny enough).
I mentioned in an earlier post that the Legend plant I cut down appeared to have fusarium wilt. This is not a good thing to have, as it affects all sorts of plants and can survive in the soil for years. I've no idea where it came from, as I've not had these symptoms before. The advice for people who have it is "grow resistant varieties".
Anyway, the Roma plant next door to the Legend also had it, and I removed this over the weekend (Roma is supposed to be resistant). I also decided to remove the Ferline plant which was dying having collapsed due to the weight of the fruit (I thought). Ferline is supposed to be resistant to fusarium wilt. This is what the stem looked like when I cut it off:
Its not easy to make out, but once you identify the cut off stem near the bottom of the photo, you can clearly see the brown areas in the xylem vessels which are charactaristic of this disease.
This is what a diseased plant looks like (also Ferline):
The plant in the middle (which was to the right of the one I just cut down) is dying from the bottom up, and has wilted in the hot sun. Unlike when the leaves die back naturally, wiggling them does not easily detach them at the leaf base, which is unusual - they remain firmly attached even when looking quite dead. The Mountain Magic (resistant to fusarium wilt) on its right is also beginning to look unhappy, but strangely the plant on the left (Ferline), which was next to the one I cut down, is ok apart from wilting a little in the heat (its 27C here today).
I think the important lesson here is the reminder that when a variety is described as "resistant" this is not the same as "immune". These varieties can still get the disease.
So, what's to do about this? Well, apparently the green manure Caliente Mustard, if grown then chopped or crushed and dug into the soil, will "fumigate" it with isothiocyanates - these are the chemicals that give things like mustard, nasturtiums and horseradish their taste. These apparently kill things like fusarium and verticillium wilt and also onion white rot (which I don't have as far as I know) - all these are fungal pathogens.
I have ordered a packet of Caliente mustard seeds (available from Marshalls) which can be sown now, and I will no doubt find out if it works next time I grow tomatoes in that area (which will be soon as it is one of the few areas that is sunny enough).
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