Notes to broadcasters
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Banana is a very important crop not only in Africa, but all over the world. It is the world’s fourth most widely-grown food crop after rice, wheat and maize, and the most important food staple in many countries in Africa. Bananas are widely grown in East African countries, while plantains, which are closely related to bananas, are a staple in West Africa. In recent years, banana productivity in Africa has been decreasing due to pests and diseases, declining soil fertility and socio-economic factors such as inadequate labour and marketing problems. The following script concentrates on simple actions which small-scale farmers can take to manage the banana weevil. It reinforces using a sustainable integrated pest management approach – in other words, using a variety of different methods (cultural, biological, genetic and chemical) to manage crop pests while protecting the environment, human health and economic viability.
Most banana workers in Africa are women, a trend which may be increasing due to migration of males in search of work. Be sure to air this program at a time when women will be listening to the radio.
Script
Characters:
Host
Mr. Emmanuel Kagaro:
Host
Mr. Emmanuel Kagaro:
farmer
BRING UP MUSIC AND FADE UNDER HOST.
Host:
Good morning [afternoon, evening]. I’m your host, [ ]. Today we’re going to talk to Mr. Emmanuel Kagaro about how he controls banana weevils… without using pesticides! Good morning [afternoon, evening] and welcome, Mr. Kagaro.
Mr. Kagaro:
Good morning [afternoon, evening].
Host:
Let’s start right in. First, I have a question for you. Is it true that you are able to manage the weevils in your bananas without using pesticides?
Mr. Kagaro:
Yes it is. But it has taken a lot of observation and experimentation to find methods that work.
Host:
You say methods. Does this mean that you use more than one method at the same time?
Mr. Kagaro:
That’s right. I learned that the actions you take to manage a pest should be based on what you know about both the crop and the pest. The more you know, the more actions you can take, and the better success you will have in controlling the pest.
Host:
So how do you manage the banana weevil?
Mr. Kagaro:
Well, before we get started, I should mention that one of the most important things to keep in mind when dealing with any pest is that a healthy plant is more resistant to attack by pests and diseases.
Host:
Just as a healthy person can fight off an illness better than a sick person.
Mr. Kagaro:
Exactly. So keeping your plants healthy is your first defense against pests. I use a good mulch of corn stalks and grasses around my banana plants. It helps to keep the soil moist, suppresses weeds and provides the plant with important nutrients.
Host:
That certainly sounds like good advice, Mr. Kagaro. Now what about the pest itself?
Mr. Kagaro:
As I said, I have several different methods for controlling banana weevils. But I always start with the motto: “Start clean to stay clean.” By “start clean” I mean that farmers should use planting materials that are not already infested with weevils or other pests. Weevils can’t move very far by themselves, just a few feet. But farmers can spread them from field to field when they use infested planting materials.
Host:
So what should you do to avoid spreading the weevils?
Mr. Kagaro:
Well the best way is to buy clean planting material from a nursery.
Host:
But that’s not always possible.
Mr. Kagaro:
No. If you can’t buy clean planting material, you must clean the planting materials yourself.
Host:
And how do you clean planting materials?
Mr. Kagaro:
One of the best ways is to pare the suckers of the banana. Use a sharp knife to remove the roots and outer corm layers to a depth of one-third of a centimetre. Make sure you kill any eggs and larvae that you find by crushing them.
Host:
So now you have clean planting materials. What’s next?
Mr. Kagaro:
Plant the suckers very soon after you pare them. That way there’s no chance that weevils can re-infest the suckers. It’s probably best to plant them about sixty centimetres deep. Some research has shown that planting suckers this deep prevents weevils from finding the suckers.
Host:
I’ve heard that some farmers use their own homemade insecticides as well as paring the suckers.
Mr. Kagaro:
Yes, that’s becoming more common. A mixture of water and powder made from seeds of the neem tree can keep weevils away from the plant. If it’s easy to get neem, it might be a good idea to use it. You apply the neem solution directly onto the corm just before planting the suckers.
Host:
Of course farmers will need to find out exactly how to make the solution, and how and when to apply it before starting this treatment.
Mr. Kagaro:
That’s right. And that’s important with any pesticide.
Host:
Is there anything else we know about the banana weevil that can help us manage this pest?
Mr. Kagaro:
Well… we know that females like to lay eggs in corms and stems. We also know they’re attracted to recently cut plants. So it’s a good idea to cut some old stems in half and lay the two halves on the ground near the banana mat with the split surface facing the ground. If you leave the split stems in the field for a week, the weevils will lay their eggs inside them. After a week, destroy the stems.
Host:
So what you’re saying is that first you set a trap for the weevils by putting cut stems on the ground, and then you destroy the weevils once they’re in the trap.
Mr. Kagaro:
Exactly! It’s also a good idea to dig out corms at the beginning of the rainy season and chop and split the stems and leave them to dry. This kills weevil eggs and larvae and gets rid of food sources and places to breed. But those are just a few suggestions. The more you know about how a pest lives, the more methods you can use to control it.
Host:
Well you’ve certainly shared some good strategies for controlling the banana weevil. And I’m sure there are other methods that other farmers are using. As you said earlier, observation and experimentation are keys to success.
Mr. Kagaro:
And both take time and effort. But the results are well worth it.
Host:
Let me just sum up quickly.
- To start with you told us the importance of keeping all plants healthy to better resist pest attacks.
- Then you mentioned your motto: “Start clean to stay clean,” which means using clean planting materials so you don’t spread the weevils.
- You told us how to pare the suckers, and you suggested that using neem is a good idea if it’s affordable.
- You also talked about trapping weevils in cut stems on the ground.
Mr. Kagaro:
I feel confident that if farmers can manage to do these things, then their banana production will increase. It may not happen immediately, but if you keep at it, you’ll have less damage and better yields.
Host:
Thanks very much, Mr. Kagaro, for your wise words on this serious pest. You certainly have given us a lot of information to think about.
Mr. Kagaro:
You’re very welcome.
Host:
This is your host, [_________ ], saying good morning [afternoon, evening].
Acknowledgements
- Contributed by Vijay Cuddeford, researcher/writer, North Vancouver, BC.
- Reviewed by Godfrey Kagezi, Research Associate, International Institute of Tropical Agriculture (IITA)-East and Southern Regional Center (ESARC), Kawanda Agricultural Research Institute (KARI), PO Box 7065 Kampala, Uganda.
Notes
Following is the basic life cycle of the banana weevil. This information may be incorporated into another radio program that covers different methods than the ones mentioned above for controlling the banana weevil without using pesticides.
- Female banana weevils lay their eggs mostly in the corm and the pseudostem, but also in the first few inches of a newly cut stem.
- After the eggs hatch, the small white larvae burrow into the corm. The larvae live for five to seven weeks, and do a lot of damage digging tunnels that make it difficult for the plant to take up water and nutrients from the soil. This reduces fruit yields and also weakens the plant, causing it to snap and topple over in high winds.
- After five to seven weeks, the larvae become black-coloured adults, which are about the length of your thumbnail and live for more than a year. They do not damage the plant, but, the female weevil lays eggs in the corm and stem.
Information sources
- Masanza, Michael. “Effect on crop sanitation on banana weevil Cosmopolites sordidus (Germar) populations and associated damage.”
- Gold, Clifford S., Jorge E. Pena and Eldad B. Karamura. “Biology and Integrated Pest Management for the Banana Weevil Cosmopolites Sordidus (Germar) (Coleoptera: Curculionidae).” Integrated Pest Management Review. Vol. 6: 79-155.
- Frison, E.A., C.S. Gold, E.B. Karamura, and R.A. Sikora, eds. “Mobilizing IPM for sustainable banana production in Africa: Proceedings of a workshop on banana IPM held in Nelspruit, South Africa – 23-28 November 1998.” INIBAP Eastern and Southern Africa Office, PO Box 24384 Plot 106, Katalima Road Naguru, Kampala, Uganda. Tel: (256-41) 286213, Fax: (256-41) 286949, Email: Admin@inibap.co.ug
- “Research on Banana and its Pests.” International Centre of Insect Physiology and Ecology (ICIPE). ICIPE, PO Box 30772, 00100 Nairobi, Kenya. Tel: 254 (20) 861680-4, Fax: 254 (20) 806330/860110, Email: dg@icipe.org
- Tinzaara, W., A. Barekye, C.S. Gold, C. Nankinga, G.H. Kagezi, P. Ragama, W. Tushemereirwe, and G. Blomme. “Use of cultural practices for the management of the banana weevil, Cosmopolites sordidus (Germar) and nematodes in Masaka District, Uganda.”
- Masanza, M., C.S. Gold, A. van Huis, and P.E. Ragama. “Effects of covering highland banana stumps with soil on banana weevil Cosmopolites sordidus (Germar) oviposition.”
- Masanza, M., C.S. Gold, A. van Huis, P.E. Ragama, and S.H.O. Okech. “Effect of crop sanitation on banana weevil Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) populations and crop damage in farmers’ fields in Uganda.”
- “Project 7: Improving Plantain- and Banana-Based Systems.” International Institute of Tropical Agriculture (IITA). IITA, c/o Lambounr (UK) Limited, Carolyn House, 26 Dingwall Road, Croydon CR9 3EE, UK.
- Picq, C., E. Fouré and E.A. Frison, eds. “Bananas and Food Security.” International symposium, Douala, Cameroon, 10-14 November 1998.
- McIntyre, B.D., C.S. Gold, H. Ssali, and S.J. Riha. “Effects of mulch location on banana weevil, soil and plant nutrients, soil water and biomass in banana fields.” Biology and Fertility of Soils. Dec. 2003: 74-79.