Brassicas, liming and crop rotation

[emarisa28]

Hello all

I am wondering this year if i should bother rotating my brassicas or just to lime over again the same patch. My thinking is if for a few years i just keep liming the same area then the PH level with carry on rising; and it may also help reduce the clubroot is other areas of my allotment if i don't plant brassicas there

Has anyone done this before and any feedback X

[toomanytommytoes]

There are other brassica diseases that could build up without rotation: last year we got white blister (hadn't ever seen it before) in a bed that hadn't been rotated for 3 years.

[Snadger]

Clubroot is a microscopic fungus. Even walking between different areas of the plot can spread it. Liming can help increase alkalinity if soil is acidic but won't necessarily prevent clubroot.

I got rid of club root and onion white rot (also a microscopic fungus) by adopting a holistic approach to my allotment and mixing different veg, flowers and fruit all over the plot in small pockets along with growing clubroot resistant varieties initially and using green manures.

And never accept brassica seedlings from other plot holders.

[dennyjim]

Clubroot is a microscopic fungus. Even walking between different areas of the plot can spread it. Liming can help increase alkalinity if soil is acidic but won't necessarily prevent clubroot.

I got rid of club root and onion white rot (also a microscopic fungus) by adopting a holistic approach to my allotment and mixing different veg, flowers and fruit all over the plot in small pockets along with growing clubroot resistant varieties initially and using green manures.

And never accept brassica seedlings from other plot holders.

I have club root and it's my first year on the plot. I lost all my Brasicas not knowing that the soil had club root. I had no idea what it was till I googled it. I'm putting in a green manure this week hoping it will still grow. As an experiment I have grown some cabbages and turnips from seed till they had a great ball root in individual 3" pots. I've limed them in along with some Blood Fish and Bone pellets and sprinkled some lime granules around all of the plants. At present I see loads of new and very healthy looking plants. Time will tell.... Next season I have succumbed to growing F1's that are supposedly club root resistant. Could you eloborate about the holistic approach please Snadger?

[Penellype]

One of the reasons clubroot is so hard to control is that it affects all members of the brassica family, which is a huge family of plants. Even if you don't plant cabbages etc on the land, clubroot can live on some common weeds such as bittercress and shepherds purse. If you grow green manures, remember that mustard is a brassica too.

Things you can do (I am not familiar with the holistic approach mentioned by Snadger, which sounds interesting) are keep the plot clear of every single weed, grow brassica seedlings in pots until they are big enough to survive, and possibly in containers for their whole growing time (not practical if you want large numbers).

Be very, very careful not to take the problem home with you if your garden is clear or to bring it back in from other plots. This is particularly difficult if you have to cross another plot or use a communal path (as I do) to reach your allotment.

I appear to be lucky as I have seen no signs of clubroot on my plot, but when one of the plot holders further down gave me some spare cabbage seedlings I didn't plant them for fear of importing the disease.

[Aberdeenplotter]

Anyone growing brassicas and has a problem with clubroot, have a look at Perlka.

https://www.lefroyvalley.co.nz/wp-co...nformation.pdf

If you decide to use it, remember you need to wait 2-3 weeks after application(be sure to check that as the time may be longer)as you may well fry your plants otherwise.

[Trouvere]

I've previously trawled the literature for clubroot control strategies, and this is what I've noted down:

(1) hot composting / soil solarization
the clubroot organism's spores are killed by 1 week at 45'C or after a couple of days at 50'C. Of course a lot of other soil life will be killed too, but it's a brute force method that might work, perhaps if you added fresh horse manure in deep trenches and then covered with black plastic

(2) bait crops
clubroot spores will persist dormant for many years, but if they germinate they must quickly infect a brassica root, or they will die. You can trick clubroot spores into germinating when there is no plant host around for them to infect by pouring cabbage root extract into the soil, or by sowing a bait crop of radishes or similar and then pulling them up early before the clubroot lifecycle can complete

(3) leeks and rye grass
they are also said to trigger germination of clubroot spores but be immune to infection; the highest number of free clubroot spores are found 2 years after the brassica crop, when remnant roots are decaying, so this is perhaps the best time to rotate leeks into the area

(4) boron supplementation
something like 0.2 grams per square metre of boric acid or equivalent, added once a year, no more; it's quite easy to reach toxic levels and cucurbits in particular are very sensitive to higher boron levels; tests show 36 to 64% reduction in clubroot infection rates

(5) liquid seaweed extract fertilizer
you'll probably be doing this anyway, but tests show 55 to 84% reduction

(6) aspirin
switches on plant salicylate defence pathways; something like 1/4 of an aspirin in a 20 litre watering can seems about right; 50% reduction

(7) Bacillus subtilis
possibly more difficult to get hold of, although I know there is a commercial product called Rhizocell C, or you could mess around with natto from an Asian food store perhaps; the bacteria colonise plant roots, help to mobilise soil phosphorus, and produce anti-fungal enzymes; 62 to 83% reduction

(8) chitosan treatment
powdered crustacean shell at about 0.4 grams per litre; switches on plant anti-fungus defences

(9) encourage earthworms
clubroot spores that pass through a worm gut are killed, but it will take a long time for all the soil to be cycled through

(10) clubroot-resistant brassica varieties
there are said to reduce infection by 70 to 90%

(11) start plants in pots until they develop good root systems
otherwise known as 'fattening them up for the kill' - no, this probably works well for brassicas that don't stay in the ground for too long

(12) liming
unfortunately the sort of pH needed to suppress clubroot, above pH 8, is too high for almost all plants except brassicas and tumbleweeds, but if you're happy to do that, it certainly helps.

[nickdub]

Hello all

I am wondering this year if i should bother rotating my brassicas or just to lime over again the same patch. My thinking is if for a few years i just keep liming the same area then the PH level with carry on rising; and it may also help reduce the clubroot is other areas of my allotment if i don't plant brassicas there

Has anyone done this before and any feedback X

Clubroot is one of those problems which are usually imported on plant or weed roots, unless you have it already on the plot.

Being very careful not to accept gifts of plants from unknown sources is the single best way to try to stay clear of it.

As for the rest, rotation of crops has a number of possible benefits, but to my mind disease prevention is not high on that list. I'd say rotate stuff around a bit if you can, but don't worry about set plans or leaving stuff in the same spot for 2 years running.

[emarisa28]

Clubroot is a microscopic fungus. Even walking between different areas of the plot can spread it. Liming can help increase alkalinity if soil is acidic but won't necessarily prevent clubroot.

I got rid of club root and onion white rot (also a microscopic fungus) by adopting a holistic approach to my allotment and mixing different veg, flowers and fruit all over the plot in small pockets along with growing clubroot resistant varieties initially and using green manures.

And never accept brassica seedlings from other plot holders.

Interesting as I've been thinking about this too; isn't this what they call Polyculture? Would you mind if I messaged you for some more information?

[Ognen09]

(6) aspirin
switches on plant salicylate defence pathways; something like 1/4 of an aspirin in a 20 litre watering can seems about right; 50% reduction

I take one aspirin a day so apart from my many health issues at least I shouldn't get clubroot seriously tho' that was very interesting and informative.

[Vince G]

My dad swears by a little chunk of rhubarb in the planting hole when transplanting seedlings. I've done this and also water during the year with water infused with rhubarb.

Have never had clubroot, maybe it's a coincidence, but I will keep doing the rhubarb thing, just in case it is this that is keeping the clubroot away.

[1Bee]

I have clubroot on my plot, but I seem to manage to crop in spite of it. I've even pulled up plants which have performed brilliantly and found the roots showing signs.. bizarre...

Apart from kales, which seem not to mind, I grow on my brassicas into 3, 4 sometimes 5 inch pots and make sure they're well established before planting out into a planting hole that's been limed. *shrug* Seems to work.

Good luck!

[Derbydal]

would root trainers work for this iv'e some that some kind person donated up the alotment? atb Dal.