|dc.description||Garlic ? a natural insect repellent
Using chemical pesticides to kill insect pests has both advantages and disadvantages. The main advantage is that they work quickly, enabling farmers to save a crop if it becomes infested with a pest. One disadvantage is that many chemicals are broad-based, meaning that they kill all insects, not just the pest species. This unfortunately means that beneficial insects, like ladybirds for example, are also killed. Another disadvantage is that chemical pesticides can be expensive, and can damage the health of both crops and people if used incorrectly.
In Bulawayo, Zimbabwe, the Lead Trust is working with orphanages to establish nutritional gardens. Those working in the gardens are being trained to use a wide variety of methods to control pests. Busani Bafana visited the Trust?s demonstration garden and spoke to extension specialist Canisius Mpala. He was curious to know more about the pest control methods. Does the Trust teach modern methods, and is there still a culture in Zimbabwe of protecting plants without using chemicals?
IN: ?The culture still exists. The problem has ?
OUT ? the numbers of the whitefly.?
BACK ANNOUNCEMENT: Canisius Mpala, an agriculture extension specialist working for the Lead Trust in Bulawayo, Zimbabwe. He was speaking to Busani Bafana, and the interview comes from a resource pack produced by CTA.
Mpala The culture still exists. The problem has been that people have been more used to using the quick fix methods, which are the chemicals, whereby if you spray, after two days the problem is gone. Right now people are discovering, due to the costs of the chemicals that they can still maintain a clean environment and save their crop using biological means. The culture is there but it has been over-shadowed by quick fix methods.
Bafana Is there a need then for agro-chemicals if we can use the biological control of pests?
Mpala The need could be there on a small scale, whereby there is a time lag between the increase in the population of the beneficial versus the pest. The pest increases faster than the beneficial. It will take some time for the level of the beneficial insect to come and control the pest. During that phase, that is when people could come and use mild chemical remedies. My organisation Lead Trust is implementing a nutritional garden programme in the orphanages in Bulawayo. We are using other plants to control insects, like interplanting garlic with tomatoes. Since garlic has a pungent smell it repels red spider mites. Or using paw paw leaves or tobacco leaves to spray for aphid pests.
Bafana What are the tangible benefits therefore, in terms of crop quality, human health, and the environment in using good insects to manage pests?
Mpala The tangible benefits are: the quality of the crop improves, because you will be having crops that are not disfigured by harmful pests; the human health is also enhanced because chances of food poisoning or chemical poisoning are reduced; you increase biodiversity, because there will be an increase in the animals or insects that are in the system that you are having.
SFX Moving outside.
Bafana Right now we are actually outside Mr Mpala?s demo garden. I can see you are holding a leaf of the chomolia plant. There are actually some aphids there. Please explain how biologically you control those aphids?
Mpala We can control these aphids by using some plants that we have in the yard. We have some aloe in the yard. We can take that, crush it in water, spray it on the leaves. This will destroy the aphids. Or we can use the garlic which we have, interplant it with the plants, and the smell will repel the aphids.
Bafana One of the leaves that you are actually holding is white in colour. What has caused that?
Mpala This is a chemical burn. We were trying to do a quick fix on one of the rows of chomolia plants. We used some chemicals and the mixing up was not done properly, and what we have now done is to burn most of the plants in the garden in that row of plants.
Bafana In front of me I can see that you have intercropped some chomolia plants and some garlic. What are the benefits there?
Mpala The benefits are we are trying to save water. Whatever space we can get between the chomolia we can get garlic growing there. But the major thing is we want to use that garlic as a repellent, that will repel any harmful pest that will attack the chomolia or the tomatoes nearby.
Bafana And the tomatoes have actually been infected with whitefly, so how then do you control them biologically?
Mpala The whitefly we could use some ladybirds. Unfortunately if you are going to use a chemical spray the ladybirds will be destroyed and therefore you are removing the predator of the whitefly, and this will lead to an increase in the growth or an increase in the numbers of the whitefly. End of track||en_US