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Geophyte discussions => General Discussion => Topic started by: Uli on March 12, 2023, 06:08:50 AM

Title: Sowing old seed
Post by: Uli on March 12, 2023, 06:08:50 AM
Dear All,

Here is a picture I would like to share with you. It shows sprouting seed of three Dahlia species and one hybrid. Not very exciting you might think but the seed was very old, stored in paper envelopes in a domestic refrigerator (not freezer) at typical fridge temperature.
The seed of Dahlia tenuicaulis in the bottom right pot dates from a trip to Mexico in 2006, the seed in the other 3 pots was picked in 2011 in my former garden. I am particularly pleased about this germination because I had lost all three Dahlias after my move to Portugal. With better knowledge of this climate I will give them another try. The blue granules are slug pellets, I do not want that to happen.......
Title: Re: Sowing old seed
Post by: Martin Bohnet on March 13, 2023, 12:10:06 AM
I can confirm that Uli treats his seeds excellent - last year he gave me Tigridia seeds from (i think) the very same trip, and they were sprouting fine. did not count them before, but above 90% seems a safe bet.

but I do have a question about the slug pellets: are those methaldehyd or iron(III)-phosphate pellets? whenever I tried to protect seed from slugs using the phosphate-based ones, they molded within days - which likely wasn't helpful for the seedlings either.
Title: Re: Sowing old seed
Post by: Uli on March 13, 2023, 02:03:13 AM
I use Methaldehyd to be sure. These pellets will also become mouldy after some time and in fragile and valuable seed I replace them with fresh ones.
My seed trays and pots are covered with wire mesh to exclude birds so this protects against accidental intoxication at the same time.
Title: Re: Sowing old seed
Post by: David Pilling on March 13, 2023, 06:55:52 AM
From a hedgehog web site (talking about 2022)

"Good News! Metaldehyde Slug pellets can no longer be sold or used in the UK, as of Friday 1st April, because they mainly contain a pesticide called Metaldehyde which poses an unacceptable risk to birds, dogs, and wildlife such as hedgehogs.

We know slugs munching on your prize-winning lettuces can be irritating but slugs and snails play a hugely important role in maintaining a healthy ecosystem! In March 2022 the RHS announces that they will no longer be classing slugs and snails as pests saying "The RHS is all too aware of the role that gardens have in supporting biodiversity and as such will no longer label any garden wildlife as pests".

Title: Re: Sowing old seed
Post by: CG100 on March 13, 2023, 07:04:44 AM
Quote from: David Pilling on March 13, 2023, 06:55:52 AM"Good News! Metaldehyde Slug pellets can no longer be sold or used in the UK, as of Friday 1st April, because they mainly contain a pesticide called Metaldehyde which poses an unacceptable risk to birds, dogs, and wildlife such as hedgehogs.


I believe that the ban is only for domestic/householder use - agricultural use remains legal?

Most? All? Slug pellets are cereal based, which is the attractant/food, the same as with rodent baits. The toxins are added at just a very few %. Hence they all mould pretty quickly if damp enough.
Title: Re: Sowing old seed
Post by: David Pilling on March 13, 2023, 07:45:30 AM
Quote from: CG100 on March 13, 2023, 07:04:44 AMI believe that the ban is only for domestic/householder use - agricultural use remains legal?

I am no expert, indications from Google, pronouncements of UK Government are that the ban applies to farms too.

Interesting comment on why slug pellets go mouldy.

Always been interested that:

"Metaldehyde was originally developed as a solid fuel. It is still used as a camping fuel, also for military purposes, or solid fuel in lamps. It may be purchased in a tablet form to be used in small stoves, and for preheating of Primus type stoves."

Title: Re: Sowing old seed
Post by: CG100 on March 13, 2023, 08:16:46 AM
Amazingly, perhaps, slugs are a very serious agricultural pest even today - at their worst they can occur at rates of hundreds, possibly thousands, per square metre in preferred soil, which would include plenty of arable land (numbers will be online somewhere).

Most baits for any species are produced using machinery designed for use in the food or feed industry - either livestock pellet/pencil making for pelleted poisons, or pasta-making machines (lots of rodent poisons are available in blue pasta shapes). The only exception that I can think of are wax blocks used for rodents, and even they are laced with cereal as well as poison. (I am unsure that tracking powder is used/legal now - I haven't seen it for sale for years.)

I know that metaldehyde was still permitted because there wasn't any realistic alternative for commercial growers - aluminium was, if not now, discounted.

I had completely forgotten the waxy metaldehyde fuel blocks!! 
Title: Re: Sowing old seed
Post by: Martin Bohnet on March 13, 2023, 11:32:49 AM
Methaldehyd is legal in Germany - I guess it's EU-wide. Wasn't Brexit made to escape all those pesky EU rules?
Title: Re: Sowing old seed
Post by: CG100 on March 14, 2023, 12:38:09 AM
Campaigns to get it banned in the UK have been going on for a very long time, since way before Brexit. Perhaps the EU has escaped a new regulation pushed through by the UK?

There would, I strongly suspect, be more people in the UK thankful to have escaped it still being legal, than the other way around.

Metaldehyde is toxic, it can kill non-target wildlife, but is there any real evidence that it does and at a significant level? Doubtful.
Title: Re: Sowing old seed
Post by: Martin Bohnet on March 14, 2023, 01:39:42 AM
Don't get me wrong, I don't use it - though i'm convinced the most "toxic" substance for hedgehogs is rubber. Lost one in our street last summer.

On the other hand I wonder if one can reach toxic phosphate levels with slug pellets. too much phosphate seems to block calcium uptake, as a quick google search turned out. too much Iron can catalyze hydroxyl radicals. So much to the theory, but does it happen? Solubility in water and thus mobility is low. still I'd guess it does more damage in pots than in the open garden.
Title: Re: Sowing old seed
Post by: janemcgary on March 14, 2023, 04:47:45 PM
I use the iron phosphate slug pellets, but instead of putting them in the pots, I put little piles of them between the pots (which are plunged almost to their rims), since the slugs are likely to hide out under the pot rims and crawl around at night between the pots. This seems to have been very effective on slugs, but it doesn't get rid of cutworms. There are enhanced products containing (can't remember the exact word -- spinosab?) which are supposed to be better, but they don't get the cutworms either. Only late-night visits with a strong headlamp work.
Title: Re: Sowing old seed
Post by: CG100 on March 15, 2023, 01:41:28 AM
Biological controls (mostly? all? are nematodes) for soil pests work very well in pots, so long as there is no major rate of  reinfestation, which is pretty much the case for things like cut-worms as they are laid as eggs very seasonally.

I stll have metaldehyde pellets and would continue to buy them as I only ever use them in the greenhouse (or very occasionally indoors, when a silver trail gives away intruders that I can't find.

If anyone has ever seen a slug or snail starting on a pellet, the poison must work extremely quickly as the molluscs are writhing PDQ after a small taste.
Title: Re: Sowing old seed
Post by: David Pilling on March 15, 2023, 08:46:35 AM
There should be something to water on plants that makes them unpalatable to creepy critters - garlic water or summink.
Title: Re: Sowing old seed
Post by: CG100 on March 15, 2023, 09:10:48 AM
Quote from: janemcgary on March 14, 2023, 04:47:45 PM(can't remember the exact word -- spinosab?)

Possibly one of the carbamates? The common one was/is methiocarb. Possibly also banned in the UK/EU????

Spinosad is a thing - a natural, reasonably environmentally-neutral compound outside of its use as an insecticide. I can't find mention of its use as a mulluscicide. It can be extremely persistant (half life of 100's days) in the environment unless exposed to water and strong sunlight simultaneously.
Title: Re: Sowing old seed
Post by: Wylie on March 16, 2023, 08:12:33 AM
I have found that most snails and slugs are clever enough to use pellets as some sort of obstacle course. I will go out at night before going to bed with a salt shaker and it seems to deter others.
Title: Re: Sowing old seed
Post by: David Pilling on March 16, 2023, 09:10:52 AM
The chief BBC gardening expert would say "if pests are a problem, grow something else" along with "all pesticides will be banned". I did not like that advice, I was going to carpet the land with Nomocharis.

But that is where I have ended up. I use very little in the way of pest control. Slug pellets just when putting out new seedlings, that is when they are most vulnerable and maybe most tasty. The rest of the time I have to put up with whatever happens.

I did spend five years growing a Nomocharis, and a slug bit the flower bud off it, and that was the end of it. Who needs a hobby that is so much at the mercy of random events and not much fun.

I can fill the garden with colour and interest, but as with the weather, only some things will succeed.

Title: Re: Sowing old seed
Post by: CG100 on March 16, 2023, 11:06:15 AM
Chemicals, across the board, used to tend to get banned due to their potential for affecting human health, general environmental concerns are now much more common, presumably as much as anything because anything new has to get past so many checks for potential human health implications.

No bad thing, but used as intended, but not in the "outside world", but in greenhouses, even in our homes, they pose no major threat to anything except the intended. The problem is that the legislating bodies have little faith in Joe Average sticking to such restrictions, although good numbers of horticultural treatments are licenced for professional glasshouse use only.

I probably have, but do not recall ever using slug pellets outddors. Inddors and in the greenhouse - certainly. I also use neo-nic's in both.
Title: Re: Sowing old seed
Post by: Diane Whitehead on March 16, 2023, 12:00:20 PM
I just pick slugs off my plants and stomp on them.
Title: Re: Sowing old seed
Post by: Martin Bohnet on March 16, 2023, 12:42:29 PM
with that method i'd have to camp 24/7 beside my dahlias, orchids and most amaryllids. my slugs have a rather exclusive taste, so I can feel with david's nomocharis pains - and it pains me that nomocharis seems to have been sunken into lilium now?

To make it worse, I can't use slug pellets in the bog garden, where the pressure on orchids is astronomically high and the slugs can re-hydrate even in mid-summer.
Title: Re: Sowing old seed
Post by: Diane Whitehead on March 16, 2023, 06:40:02 PM
Well, Martin, if you had a dry garden like mine, you wouldn't have many slugs.
Title: Re: Sowing old seed
Post by: David Pilling on March 16, 2023, 07:07:00 PM
Quote from: Martin Bohnet on March 16, 2023, 12:42:29 PMit pains me that nomocharis seems to have been sunken into lilium now?

Yes, merging Nomocharis into Lilium has been on the cards for some years, Mary Sue has recently made the changes on the PBS wiki. Pity because they are different to most lilies.

Changing "Nomocharis hybrids" to "Lilium hybrids" is a bit misleading, but if they're all Lilium what else can you do.
Title: Re: Sowing old seed
Post by: CG100 on March 17, 2023, 01:06:43 AM
They must surely have their own group or sub-family?
The latin form of Nomocharis will have changed but presumably still exists?
Title: Re: Sowing old seed
Post by: fierycloud on March 17, 2023, 02:41:21 AM
 Front. Plant Sci., 01 February 2022
Sec. Plant Systematics and Evolution
https://doi.org/10.3389/fpls.2021.699226 (https://doi.org/10.3389/fpls.2021.699226)
Phylogeny, Age, and Evolution of Tribe Lilieae (Liliaceae) Based on Whole Plastid Genomes
[img width=30px]https://www.frontiersin.org/files/Articles/699226/fpls-12-699226-HTML-r1/image_m/fpls-12-699226-g001.jpg[/img]
Title: Re: Sowing old seed
Post by: David Pilling on March 17, 2023, 03:06:10 PM
Quote from: fierycloud on March 17, 2023, 02:41:21 AMhttps://doi.org/10.3389/fpls.2021.699226

Good reference. Maybe one can now cross Lilies with Nomocharis to gain more robustness.

PBS Nomocharis wiki page:

https://www.pacificbulbsociety.org/pbswiki/index.php/Nomocharis