Discussions about organic slug control
(1999 - 2001)

postings: 15
countries: Australia, Costa Rica, Honduras, Nicaragua, United States
organizations/institutions/companies: Cafesombra, CATIE (Nicaragua and Costa Rica), CIIFAD/Cornell University

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Discussion #1: slugs and mulches (1/19/99 - 1/20/99) ______________________________________________________

Date: Tue, 19 Jan 1999
From: Donald Kass
To: MULCH-L@cornell.edu
Subject: slugs

Dear Mulchers,

One of the perennial objections of farmers and others to using mulches are that they increase the incidence of slugs. My experience is that they don't usually do so in wet seasons, when slugs have other things to eat and places to hide, but in dry seasons, mulches and crops will generally attract slugs since there are fewer moist refuges and succulent alternatives.

We always used to control slugs with baits but most of these are not organic and hence unacceptable in organic farming practices. Beer has always been suggested but it becomes quite an expensive operation in a planting of more than 1/10 hectare where one would have to put out at least 100 beer traps--each trap rarely catches more than five slugs and change the beer daily since slugs don't seem to like flat beer any more than Homo sapiens. An organic bait would seem better but most of what I have used as organic insecticides (garlic, hot peppers, soap) would more likely repel slugs than attract them. I doubt that one could disguise the odor of hot peppers or garlic to deceive even a slug.

Well, there is my problem. Of course, using baits would not mean that the crop would be contaminated with a toxic pesticide. However, as we all know, there are many purists in the organic field and organic means no pesticides even near the crop.

All suggestions are appreciated.

Don Kass
(CATIE, Costa Rica)

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Date: Tue, 19 Jan 1999
From: Bedigger
To: MULCH-L@cornell.edu
Subject: Re: slugs

Iron phosphate slug bait is reportedly an alternative with extremely low toxicity to mammals. I believe that it is organic. It is marketed in the US as "Escar-Go" by Gardens Alive. I don't know if it is sold commercially (ie to nurseries and farmers) under a different name, or if it is sold out of the the US. It is patented and offered through very limited channels---unfortunately for consumers and probably the patent holder as well.

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Date: Tue, 19 Jan 1999
From: Robert H. Faust
To: MULCH-L@cornell.edu
Subject: Re: slugs

Regarding slugs;

I have found that fresh green tobacco leaves both attrach slugs in my mulched gardens and kill them, so I grow a tobacco plant for that purpose, i don't smoke it!! This is a fair "organic" approach, and does work,untill the tobacco is gone or dried out. Of course dead line, a metahyde pastes you drip around the edge of the garden is more effevtive. It's not on the crop and not toxic,to any thing but slugs, but the purists of organics won't allow it. I have seen many crops ruined by slugs,"but they are organic slugs now"

Robert H. Faust
(Hawaii)

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Date: Tue, 19 Jan 1999
Reply-To: MULCH-L@cornell.edu
From: Butch Ragland
To: MULCH-L@cornell.edu
Subject: Re: slugs

Can you explain in more detail how this could be used. Would a circle of tobacco plants around a plot keep the slugs out. Could some small growing nicotina be interspersed.

Saturating the ground with vinegar will kill slugs but that would seem expensive or impractical.

Anyone with more experience with tobacco plants?

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Date: Tue, 19 Jan 1999
From: Robert H. Faust
To: MULCH-L@cornell.edu
Subject: Re: slugs

Actually the tobaco leaves are used in the mulch layer, the leaves are layed around the base of plants or as a mulch on the edge of the garden. Intercepting slugs coming into the garden, especially small ones, kills em'

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Date: Tue, 19 Jan 1999
From: Cafesombra
To: MULCH-L@cornell.edu
Subject: Re: slugs

my great grandfather used to soak two cigar butts in a quart of water for two weeks and then use it as a pesticide spray. lethal indeed. wouldn't pass organic certification, or shouldn't anyway. nicotine will kill anything. probably you could make a poisonous stew out of fresh leaves in a bucket of water for this purpose. growing tobacco as a living reprellent won't work as for as i know.

the ducks remedy recommended earlier would probably be equally as lethal. ducks are like terrorists in a garden, they eat the plants and especially seedlings you are trying to protect from the slugs.

there is a copper tape available from one of the US seed companies ~ Johnny's? ~ apparently slugs will not cross copper, you lay the tape out around garden beds or around individual plants, sounds pretty expensive. I have seen folks use copper piping, they happened to have some to recycle that way.

you could try praying. not much else i know to do about slugs. enjoy your day everyone~

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Date: Wed, 20 Jan 1999
From: Agfayan
To: MULCH-L@cornell.edu
Subject: Slug answer

DUCKS

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Discussion #2: Garden invasion by brown slugs (7/16/01 - 7/19/01) ______________________________________________________

Date: Mon, 16 Jul 2001
From: mag
To: MULCH-L@cornell.edu
Subject: Slugs

Brown slugs have invaded my composted garden (hay, leaves, manure). Cups of beer got 75 in one night. Four days later I see some again. Am worried They'll get the whole garden. They're settling in the hollow tubes of onions, climbing garlic, destroying pepper leaves, perching on the top of pea vines, etc. No, I don't think they are army worms as they have no stripes. Some are three inches long. Suggestions? Please reply to: mag@sover.net Thanks.

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Date: Tue, 17 Jul 2001
To: MULCH-L@cornell.edu
From: Donald Kass
Subject: Re: Slugs

Try spraying with commercial ammonia diluted 1:2. You could also use lime--anything alkaline. Slugs can't tolerate anything alkaline. They won't cross a lime barrier. Beer is too expensive to be effective. Also try traps. Soak a burlap bag in beer or molasses. Put it under a board. The next day it should be full of slugs. Then, you can spray the slugs with ammonia or get rid of them any way you choose. I have also tried a mixture of buttermilk and flour--it dries out the slugs and attracts birds which eat them. Bringing in toads or box turtles will also help--they eat slugs.

Look up organic slug control on a website. There are many solutions. They really arent as hard to control as people think.

Don
(CATIE, Costa Rica)

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Date: Thu, 19 Jul 2001
From: mag
To: MULCH-L@cornell.edu
Subject: Re: Slugs

Thanks a lot! The ammonia won't hurt the plants? I'm trying to keep the garden organic.

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Date: Thu, 19 Jul 2001
To: MULCH-L@cornell.edu
From: Donald Kass
Subject: Re: Slugs

I got the recommendation for the ammonia off an organic web page. Apparently, there is no danger to the plants--though it is better to dilute the ammonia--in fact, they may take up too much and become overly succulent. You can always trap the slugs first--soaking a burlap bag with something high in carbohydrates and putting it under a bag and then spray them with ammonia or hydrated lime. If there are birds around, try the flour and buttermilk mixture--here I got a whole flock of egrets that made short order of the slugs.

I don't know why we had such trouble with slugs in pre-organic days. It seems that going organic has come up with better solutions.

Don

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Discussion#3: Slugs and mulch-based cropping (3/9/01 - 3/12/01) ______________________________________________________

Date: Fri, 09 Mar 2001
To: MULCH-L@cornell.edu
From: Charles Staver
Subject: SLUGS and mulch based cropping

Colleagues:

In CATIE in Nicaragua we have been working in humid lowland tropics with improved pest management for late rainy season bean production (December planting). In many areas this is still a fallow type production system called frijol tapado. However, land use has intensified in other areas and farmers now use pesticides to burn down weeds from the previous maize crop planted with the first rains (May planting). After weeds are burned down, they are removed to field borders to reduce slug problems. There is a dry season from February/March through May.

We would like to experiment with the use of green manures planted with the maize which continue growth after the maize harvest and are then slashed and left for bean planting. A major pest of beans in the area is often slugs. In my reading about no-till systems in Brazil etc I have seen very little reference about to slug problems. HOwever, my brother mentioned them in eastern USA coastal maize and soybean production.

Several questions about slugs and green manures:

• what is the experience with different green manures as habitat for slugs?
• what management has been used successfully? I am familiar with the need to control early in the season to avoid late season buildup. I am particularly interested in non-pesticide approaches, but also approaches which are low in labor.
• in longterm systems do slugs continue to be a problem?
• how are slugs managed in the vast areas of no-till in Brazil?

We are planning an experiment with farmers for May planting and are considering the use of either Mucuna or Canavalia with and without early season slug control compared to local tillage and vegetation management.

Any suggestions?

Charles Staver
(CATIE, Nicaragua)

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Date: Fri, 09 Mar 2001
To: MULCH-L@cornell.edu
From: Donald Kass
Subject: Re: SLUGS and mulch based cropping

Dear Chuck et al.,

The slug problem is overexaggerated. The last time I had a problem, I entered organic-slug-control in a search engine and came up with a whole bunch of solutions. The one I tried was a mixture of flour and buttermilk. Not only did it dry out the slugs--it made them more palatable to the egrets which came and ate them all. Supposedly, slugs can't take anything alkaline--spraying with ammonia is also supposed to work. Any kind of bait--which doesn't have to be toxic--will also work. It will attract the slugs off the plants where they can be killed by conventional means. Beer works but is too expensive. I tried dog food which was suggested by the website but the slugs didn't seem to like the cheap Costa Rican dog food. So far, I have had the best results with the flour-buttermilk mixture.

Recently, we have tried a dwarf pigeon pea with farmers. They were very happy with it--they told us it was the best thing we had brought them in two years. It isn't very leafy but they felt it could be grown with most crops with no difficulty. It also produces an edible seed in about four months which can be used for human or animal food. It only gets about a half-meter tall. For competing with weeds, I would stick to Canavalia but we should be looking for leafier Vignas and Phaseoli.

Don

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Date: Fri, 9 Mar 2001
To: MULCH-L@cornell.edu
From: H. David Thurston
Subject: Re: SLUGS and mulch based cropping

Dear Chuck,

I can't answer your questions, but when I went to my database I found the following references that mention slugs. I thought they would be of interest to some of the Mulch-L readers.

1. Andrews, K.L. 1987. La importancia de las babosas veronicéllidos en Centroamerica. CEIBA. 28: 149-153. babosas veronicéllidos, slugs, Central American, mulches, losses, part of a conferences on slugs with CATIE, slash/mulch
2. Arias, F. and M. Amador. Year. Frijol tapado, un sistema ventajoso para el pequeño agricultor. In: M. Bolaños Arquin and I.B. Arquin. I Simposio Sobre Tecnologia Apropiada y Agricultura Biologica Para un Desarrollo Rural Alternativo. San José, Costa Rica.: CICDAA, COPROALDE, Univ. Costa Rica. frijol tapado, minimum tillage, tapado, web blight, Rhizoctonia solani, Thanatephorus cucumeris, fungi, beans, slash/mulch, less problem with insect (Diabrotica) in tapado system, slugs a problem (Vaginulus spp.), 85% of beans in Costa Rica are from small farmers (campesinos) according to the Agricultural Census of 1984, mulching, 65% of beans in Costa Rica are from frijol tapado
3. Beaver, P.C., R.C. Jung, and E.W. Cupp. 1984. Clinical Parasitology. 9th ed. Lea and Febiger, Philadelphia. 825 pp. nematode, Angiostrongylus costaricensis, nematode attacks children, the infective-stage is larvae in tissues of a common slug (Vaginulus plebeius), Adult worms found in cotton rat and black rat, found in Costa Rica, (causing abdominal angiostronylosis), Human infection occurs (maily by small children) by accidental ingestion of slugs, nematode larvae are passed in feces of rats, caused a fatal nematode infection in small children, many cases have occurred in Costa Rica nematodes, Angiostrongylus costaricensis, abdominal angiostronylosis, slug (Vaginulus plebius, rats
4. Bentley, J.W. and K.L. Andrews. 1991. Pests, peasants, and publications: anthropological and entomological views of an integrated pest management program for small-scale Honduran farmers. Human Organization. 50: 113-124. Pests, peasants, anthropological and entomological views of an integrated pest management program for small-scale Honduran farmers, traditional agriculture, Honduras, slugs, army worms, IPM
5. Bentley, J.W., G. Rodriguez, and A. Gonzalez. 1993. Ciencia y pueblo: campesinos Hondureños y control natural de plagas . pp. 33-40. In: Buckles, D. Gorras y Sombreros: Caminos Hacia la Colaboración entre Technicos y Campesinos. CIMMYT, Mexico., Mexico City. Pests, peasants, Honduran farmers, traditional agriculture, Honduras, slugs, army worms, IPM
6. Pitty, A. and K.L. Andrews. 1990. Efecto del manejo de malezas y la labranza sobre la babosa del frijol. Turrialba. 40(2): 272-277. slugs, Honduras, mulching, weeds,
7. Rizzo Boesch, R. 1992. Efecto de una cobertura vegetal en la incidencia de la pudrición de mazorcas de maiz y la babosa del frijol In . Escuela Agrícola Panamericana. cover crops/green manures, slugs, beans, maize, maize rots, mulch MBA (from Honduras) - File
8. Rizzo Boesch, R., et al. 1994. The effect of two diets based on leguminous cover crops on weight gain and reproductive capacity of the slug Sarasinula plebeia Fischer . pp. 109-114. In: Thurston, H. D., M. Smith, G.Abawi, S. Kearl (eds.) Tapado. Slash/Mulch: How Farmers Use It, and What Researchers Know About It. CIIFAD and CATIE, Cornell Univ., Ithaca, NY., The effect of diets based on leguminous cover crops on the weight increase and reproductive capacity of the slug Sarasinula plebeia, mucuna, velvet bean, Canavalia ensiformis, Mucuna puriens, slugs lost weight on mucuna diet and did not, green manures/cover crops, reproduce, mulch
9. Rodriguez V., C.L. 1988. Consideraciones sobre la distribucion y ecologia de las babosas en Costa Rica. Ceiba. 28(2): 201-202. slugs, Costa Rica, mulching, weeds,
10. Rosemeyer, M.E. 1994. El cultivo organico de frijol en Costa Rica In. beans, frijol tapado, organic beans, Costa Rica, slash/mulch, slugs, diseases, HDT File - Mimeo

The database can be accessed at:

http://tapp.mannlib.cornell.edu/

Saludos,

Dave Thurston
Dept. of Plant Pathology
Cornell University

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From: Reid, Aileen
To: MULCH-L@cornell.edu
Subject: RE: SLUGS and mulch based cropping
Date: Mon, 12 Mar 2001

It may not be appropriate but we have a new slug control product over here that is organically certified which is a copper silicate. Obviously copper kills slugs! The company is also looking at trying to register it for disease control as the copper component has fungicidal properties. I can supply contact details if anyone wants it.

Aileen Reid
Perth, Austrailia