Topic: Nemaslug: no benefit with potatoes?

[Ellen K]

Well, I thought I'd give nematodes a try as they have rave reviews on Unwins website.

My potato patch got 2 doses: first dose end May, second dose end July - 10 quid a shot but I wanted a proper test.

Dug up my Picasso spuds yesterday - and the slugs had had a few goes at almost every one of them.

I had watered well so the spuds were HUGH but sadly they went in the skip.  However, they were gone this morning so perhaps someone will get some benefit.

So, another story from the Organic Bible debunked.  Don't waste your money, buy proper chemicals instead.

Grrrrr.

[goodlife]

I've used it in past with really good results... ??? ..and I couldn't recommend highly enough.
Perharps our soils are so different type that it would have effect for the movements of these little things?

[hippydave]

why throw them in the skip they will still be usable and store quite well

[grawrc]

Another vote for Nemaslug here. I've always found it decimates slugs, but this year has been ... well ... different? so maybe that's why or maybe it's what Goodlife said. Anyway I think it's great stuff but very pricey.

[Robert_Brenchley]

Maybe the soil was too dry for the nematodes?

[saddad]

I've found they work well too... even on our heavy clay, which even the makers (providers) say isn't ideal for them, the benefit also seems to be cumulative...
It has been very dry.. so if you watered them heavily you would attract any slugs from a wider area... the fact they were only nibbled... rather than riddled may imply the nematodes worked... affected slugs stop feeding...
I'd rather face the odd slug hole than eat "pristine" potatoes full of poisons...  :-X

[Ellen K]

Hi - just back: dug up the Setanta which were similar to the Picasso and the Desiree which were almost untouched (YAY!).

Spuds got the sprinkler maybe once or twice a week so the ground should have been wet enough for the nematodes.  But with the weather we've had, it has been hard to overwater.

Yet to dig up the PFA, I had 4 main crop varieties, 10 tubers each.  So plenty of nematodes to go around.

I don't think the nematodes did anything and the susceptible varieties took the hit.

It's possible that the second pack was dud I guess.

I was ready to jack in growing MC spuds so it was good to dig up the Desirees.

But I was worried about the Biological Warfare aspect of using nematodes, they are supposed to be safe but they are parasites after all.  And they don't even blooming work  >:(

[Ellen K]

Should add: I am Year 3 on heavy clay.  Some varieties I've tried like Golden Wonder were a total loss from slug damage.  Somebody else believed my Picassos were salvageable because thy were rescued from the skip but most of them had multiple entry/exit holes and as there is just me at home, I still hope to get enough good ones to keep me in spuds over the winter without eating what the slugs left behind.

But I do seem to have a lot of slugs in spite of keeping the plot clear.  And possibly these things might work better if more people used them.  But for me - no evidence they did anything.

[goodlife]

Hmm....perharps the nematodes have done their job..but it is just too big job for them clear in a one year ???
..and given this odd weather too.. over worked, I say.. ;)

[Ellen K]

^^ the problem is that you wouldn't resort to paying out for the treatment unless you had a serious slug problem.

I did not expect 100% clean up but have been surprised at just how ineffective it has been for the Picassos.

[manicscousers]

we've found that red varieties and kestrel have much less  problems with slugs :)

[Trevor_D]

I always use nematodes on my earlies and I find they are very successful.

But Picasso are rather prone to slug damage. Desiree always seem OK though.

[Ellen K]

Hum ... now I am wondering whether to do another trial next year - one row gets the nematodes, another row same planting but no nematodes to see if there is any difference.  The scientist in me says that would be worth a go, d**n her!

[strawberry1]

I wonder if watering with a weak salt solution would work? or perhaps diatomaceous earth

[Robert_Brenchley]

Salt kills most plants. Ever heard of the old practice of sowing an enemy's fields with salt?

[cornykev]

I used it on my maincrop and they've still been eaten.   :'(

[goodlife]

I think the biggest problem with nematodes is that the ground conditions have to be spot on or all the effords will be wasted. Soil should be in nice crumb, evenly moist, warm enough and not too compacted so that nematodes and slugs can easily travel through it and meet each other with passionate embrace.. ;)
And then after the application the soil should stay moist long enough for the nematodes to do their evil deeds and multiply.
If there is dry pockets in soil neither party will move about.. ::)
If I would have tried to use them this summer..it would have been waste...even if the soil was moist at places..it dried out very quickly and we've hardly had any rain for all summer. Even now the soil is not right for the treatment..
I think just as the soil is rotavated that would be ideal time to apply...soil would nice and 'fluffy' good for a little slug dating game.

[saddad]

I have used them on and off for several years... and some seasons they seem to do nothing... but now most of my potato beds are virtually slug free... so I'd persevere Ellen..

[Ellen K]

The thing is: they didn't work in spite of two treatments in one season.

And they didn't work for Kev's spuds either.

So you have to conclude that they are not particularly effective.  You can speculate on why that is but it may be that they take 10 days to kill a slug and by that time it has munched on your crop and spawned a new generation to do the same.  That is my theory anyway.

[chriscross1966]

I reckon this year would have been really bad for nematodes, just too dry, they'll die before finding a slug.... slugs not moving much so you don't get the endemic infection... last year one dose just as it started raining for a week in May and the fact that my spuds were growing through weed mulch woven plastic... ground stayed moist and warm, slugs moved about well before the maincrops were forming decent sized tubers and the nematodes got the lot....