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Using eucalyptus leaves to preserve maize and bean seed

Post-harvest losses account for a considerable contribution to the total crop losses incurred by farmers. Most of the times, agricultural produce prices are very low just after harvesting when there is plenty of produce for sale. In some instances, farmers need to store seed for next season. These and many more factors call for produce preservation methods. The use of synthetic chemicals in seed and grain preservation has cost and health implications to the farmers and the consumers of the treated produce.  There is need for simple, cost effective and safe methods of seed and grain preservation. Let me share with you a technology used by Andrew Chemonges, a farmer from Kapchorwa to preserve maize and bean seed.

How the practice works

The farmer uses either of the two options below;

Option one:

To preserve 100kg of seed; the farmer gets a full basin of dry eucalyptus leaves and divides them into three equal portions. One portion is put at the bottom of the sack in which the seed will be stored. The seed/gain to be stored is then poured into the sack until it is half way full.  Another layer of eucalyptus leaves is put and more seed/grain is poured until it is full. A final layer of eucalyptus leaves is put on top and the sack is sealed.

Option two:

The farmer mixes 100kg of the seed with a full basin of dry eucalyptus leaves. The leaves are mixed thoroughly to ensure uniform distribution. The mixture of the seed and the leaves is then packed in a sack and the sack is sealed.

The farmer says both approaches, can keep the seed pest free for a period of six months if kept in a dry place under a leak proof roof. He says putting the leaves in layers make it easy to sort out the leaves when the grain is being cooked.

Caution: if the grain is to be cooked, all the eucalyptus leaves should be sorted out and the grain washed with water to avoid having the eucalyptus aroma in the food.  


Karin Nichterlein's picture

This is again an interesting traditional practice, used as indigenous control of storage and other pests around the world where Eucalyptus grows: in Uganda is has been observed around the Lake Victoria basin (see paper from 2008: http://www.academicjournals.org/ajest/PDF/pdf%202008/Oct/Mugisha-Kamaten...), but no details are given on how it is used.

You might contact the author the corresponding author located at Botany Department of Makerere University. If you have Community knowledge workers in that region you might be able to get more information. Or perhaps other members of this group can help?

Just to share similar experiences around the globe:
Eucalyptus leaf extracts are used by tribal people in Tamil Nadu also in combination with wood ash (see the article from 2009 in the Indian Journal of Traditional Knowledge: http://nopr.niscair.res.in/bitstream/123456789/3959/1/IJTK%208(2)%20218-224.pdf). Research has been done in India studying the use of Eucalyptus leave extract to control Angoumois Grain Moth, a storage pest of maize and rice seed (http://www.arccjournals.com/pdf/ijar2-34-4/ijar2-34-4-012.pdf). The use of Eucalyptus leaf extracts in Egypt is cited, see: http://ip.aaas.org/tekindex.nsf/2a9c4e44835b04ea85256a7200577a64/84ee562....
Its use in Bolivia to control insects has been mentioned (http://www.unesco.org/most/bpik22-2.htm).

Since most of the literature published on the web does not provide details of the practice, your work to develop a good description of the practice as used by farmers in Uganda is very valuable.

This is a very interesting practice that I was completely unaware of! After looking into it more, it seems like a very practical and has has success! A few research journal articles have supported the Eucalyptus leaf as a stored grain protectant against pests. For example, I have included three summarized texts and their links, that show the Eucalyptus leaf's successes as a protectant.

Evaluation of botanical products as stored grain protecting against maize weevil, Sitpphilus zeamis(L.), on maize.
Mulungu, L.S.  Lupenza, G.  Reuben, S.O.W.M   Misangu, R.N.
Journal of Entomology; 2007. 4: 3, 259-262. 22 red.


The study evaluates leaf powder botanical products of Eucalyptus, as well as others, in comparison to synthetic chemicals and no insecticide controls, against the infestation of maize weevil on stored maize grains. Pawpaw leaf powder showed the best results; however, the weight loss in stored maize grains was also less in grains treated with eucalyptus leaf powders. The study supports that eucalyptus leaf powders can be good alternatives to synthetic pesticides. It appears that Pawpaw is also a good practice to implement if Eucalyptus leaves are not available. http://scialert.net/fulltext/?doi=je.2007.258.262&org=10

Botanical Pesticide mixtures for insect pest management on cowpea, Vigna unguiculata (L.) walp plants- 2. The pod borer, Maruca vitrata Fab. (Lepidoptera: Pyralidae) and pod sucking bug, Clavigralla tomentosicollis Stal (Heteroptera: Coreidae).
Oparaeke, A.M. Dike, M.C. Amatobi, C.I.
Agricultura Tropica et Subtropica; 2005. 38: 2, 33-38. 23 red.


Eucalyptus  and Neem leaf extracts mixed with extracts of other plant species are investigated for efficacy in managing two post flowering insect pests of cowpeas. Results show that plots sprayed with leaf extracts of Eucalyptus + African Bust tea (and many Neem leaf + something) reduce the pod borer by <1.0/flower and/or pod. Pod sucking bugs are suppressed ,1.5/plant on plots treated with Eucalyptus + African Bust tea (and many varieties of Neem leaf + something). The extract mixtures cause great reduction in pod damage per plant and higher grain yield compared to unsprayed plots during the two year investigation.


Efficacy of mint and eucalyptus leaves on the physic-chemical characteristics of stored wheat against insect infestation.
Modgil, R. Samuels, R.
Nahrung; 1998. 42: 5, 304-308. 14 ref.


Wheat grain treated with eucalyptus leaf powder was stored for six months in four storage structures. Monthly samples were analyzed. After six month of storage, no significant changes were observed in treated grains, whereas untreated grain experienced more damage and decrease in weight and density. Mint lead powder protected wheat for 6 months, whereas eucalyptus leaves were protective for 5 months.


These studies offer insight into the effectiveness of eucalyptus leaf powder, along with mixtures of the leaf and other plants, and possible alternatives.

Thank you so much for sharing this interesting technology with us!

Dear Members,

Thanks for sharing.

I managed to get some testimonies from different farmers with experiences in using several preparations to control storage pests in maize and beans. Please find their testimonies bellow.

Salongo Kazibwe from Mukono District in Central Uganda uses a mixture of Eucalyptus leaves, ash, Mexican marigold and hot pepper to control storage pests in beans and maize. He picks fresh eucalyptus and marigold leaves and ripe hot pepper fruits and dries them separately under shade. He grinds each of the ingredients into a fine powder. He then mixes 2 half litre cups of the eucalyptus leaf powder, 2 cups of ash, 1 cup of hot pepper powder, 2 cups of Mexican Marigold powder and mixes this mixture with 100kg of the grain. The treated grain is then packed in sucks. This grain can remain pest free for over five months. The grain can be planted or washed and cooked for food.

Richard Byaruhanga from Masindi District in western Uganda uses Ash, dry hot pepper powder and dry Cypress tree leaves to control storage pests in maize and beans. He mix about 1 kg of ash, half a cup (half litre cup) of hot pepper powder and one handful of Cypress leaves. This mixture is then mixed with one tin of beans (about 20kg). The grain stored can remain pest free for one year.

Moses Odekaje from Mukono District in central Uganda uses Mexican marigold leaves to control storage pests in beans. He dries the beans and before packing them for storage, spreads them on a tarpaulin or polythene sheet and uniformly spreads Mexican marigold leaf powder on top of the bean. He then packs the beans in a suck for storage. He says this method can keep the beans pest free for 3 months. The beans can be washed and cooked for food or planted.

Eucalyptus leaves have been used on several occasions in my village and at my own home. This has yielded awesome results in controlling weevils especially in beans, with no negative impacts on the grains. Am pleased to read about this now published technology. Thanks Possiano for this realistic and cheap technology. Am going to encourage even more people to use it.

As Jennifer said, it is nice to have such a realistic and cheap technology being presented! Although, Jennifer, would you mind letting us know how the eucalyptus is used in your village or at home- what exactly is your technique? It is so interesting to hear of the different mixtures and methodologies throughout different areas.


For the previous discussion about pig intestines as termite control, someone mentioned Tephrosi leaves which I began to read about. I found a few references about the usage of Tephrosia leaves as pest control in grain storage, does anyone have any more information on this?

I have read that in Tanzania there was a study about Tephrosia leaf's effect on cowpea weevils in stored cowpea grains. It was concluded that leaf powders of Tephrosia, tobacco snuff and combination of neem and Tephrosia are effective in controlling stored grains of cowpeas (http://docsdrive.com/pdfs/ansinet/ajps/2006/91-97.pdf). Also, in Malawi and Zambia, a study was done about small farmers knowledge of pests in stored maize and beans. Storage methodologies were different in both countries, but Tephrosia was most frequently reported as used for a pesticidal plant. (Farmers' insect pest management practices and pesticidal plant use in the protection of stored maize and beans in Southern Africa).

Could anyone offer more insight onto the Tephrosia leaf? Thanks!!

Thanks Molly. In response to your question, in my village (Hima village in Kasese district-Uganda)and at my home, these are the steps we take to preserve beans;
After harvesting and drying the seeds, but before packaging, fresh eucalyptus leaves are thoroughly mixed with the seeds. Some small branches with leaves (small enough to fit in a sack) are laid horizontally at the bottom of the sack and others put vertically in the storage material (a sack for our case). Then the mixture of seeds and the leaves is put in the sack and some leaves spread as cover on top. However, enough aeration should be provided so that the drying leaves do not cause moisture build up. When i became curious and asked my Mother why she mixes seeds with leaves, she told me that as the leaves dry and the smell becomes strong, the bean weevils will be driven away by the strong smell produced by the leaves. With this technique, we would manage to keep bean seeds until the next season without weevils. But, some times when the smell decreases, there is need to add fresh leaves if the beans if they should store for more than 4 months. We would eat some and even plant some without any harmful side effects. Once again am excited to read about this technology, that i thought was invented by my mother, be shared by many educated people. Keep it up!!

Hi, this is Lea from the Teca group, FAO, I am trying to structure this really interesting technique of preserving seeds.

Thanks Jennifer for sharing your experience also. It seems to be quite similar to Option 1 suggested by Possiano, only that you additionally lay the leaves vertically in the sack.

Dear Possiano, I found your description very detailed, still I have some questions to make sure I got you right:

1. are the leaves the farmers are fresh (like in Jennifers case)?

2. can you again define more in detail
a) how much is in a "cup" and what then means "2 half litre cups" as you mentioned it in the case of Salongo Kazibwe from Mukono District
b) how much litre is a “full basin”?
c) by “ash” do you mean a specific origin of the ash?

Thanks again for sharing your knowledge. I think it is something very important as storing techniques are so essential!

Dear Lea,

Thanks for your contribution.

In all option explained, farmers use dry eucalyptus leaves. Fresh leaves are picked and dried under shade to keep the aroma which repels the pests.

Because farmers do not have weighing scales, they usually use available means to measure quantities of different materials they use. In this practice the farmer uses a plastic cup whose volume is half a litre. The cup holds approximately 0.5kg of grain. By two half litre cups, I meant the farmer adds two of these cups. The basin used in this case holds 10litres of water and about 20kg of grain (when heaped). The ash used is ordinary wood ash and therefore its source does not matter much. Farmers usually use ash collected from the kitchen fireplace where several types of wood have been burnt.  

Thanks again for the question; they are an opportunity to explore more.  

In this brief article about post-harvest management in India it says regular smoking with (neem and) eucalyptus leaves could help to avoid seed damage. Maybe you have also experiences with such "smoking methods"?


Thanks again for giving me details on the measurement units.

I was wondering why farmers use it speficically for maize and beans. As far as I know it is a very important staple food, so it might be of priority.

But does the Eucalyptus method also apply to other grains/seeds? If no, do you know why only for maize and beans?