Plants that repel harmful insects and pests if properly grown are as effective as insect and pesticides commonly used in farming, says an environmental expert.
These ‘miracle plants’ can be grown on a farm, in a garden or courtyard, but many smallholder farmers may be unfamiliar with them.
Smallholder farmers may find natural protection of crops effective, but may know very little or nothing at all how to effectively protect their food or cash crops against the attack of predacious insects and pests. In most cases they are risk takers and may harvest little where they could have a bumper harvest and may spend money where they could have saved it.
In such uncertainty what can they do to engage in productive farming? The Business Wiz interviewed Envirocare Project Manager, who is also an environmental engineer, Amos Mbwambo, on plants which repel predaceous insects and pests to find out whether a smallholder farmer could grow food or cash crops naturally without running the risk of insect and pest attacks and ending up yielding nothing.
Mbwambo was asked about the amount of insect and pest repellent plants a smallholder needed to protect his or her crops and this was what he said. “It all depends on the size of farm or garden a farmer has. There is no specific standard that can be used to determine the ratio between the size of farm or garden and the amount of insect and pest repellent plants a farmer must have,” he said.
He explained that good practices showed that most of the insect and pest repellent plants were planted on the boundaries of a farm or garden and served as a fence to protect the insects and pests against entering the farm or garden and usually would be at an interval of from 50-100 centimeters from plant to plant.
“Botanical repellents include citronella, which repels bugs, flies and mosquitoes. Lemongrass repels bugs, houseflies, fleas, lice, ticks, mosquitoes and other insects. Lavender repels bugs, moths, flies, fleas and mosquitoes. Marigold repels nematodes, cabbage worms, mosquitoes and pests. Allium repels pests, cabbage worms, aphids, carrot flies and slugs. These are just some of them. We are familiar with some of these plants, but we may be unfamiliar with their insect and pest repelling properties.”
Using botanical repellents may look impossible and farmers are skeptical about their effectiveness and that is why they go for insecticides and pesticides. However, Mbwambo said botanical repellents were affordable and user-friendly. He explained that since his organisation promoted environmental protection and conservation and organic farming he wished farmers to engage in environmentally friendly agriculture.
He was also asked whether he had any specific district or region in the country in which they had a project on botanical repellents. He said they had implemented such projects in Kilimanjaro Region. “Most farmers have adopted this technology because it is affordable compared to commonly used insect and pesticides.”
He recounted that farmers were helped to understand and grow botanical repellents through training in integrated pest management (IPM) and encouraged them to practise organic farming to save costs and get health and environmental benefits.
On whether these ‘miracle plants’ also controlled plant diseases such as black spot, leaf spots, powdery mildew, blight and canker, Mbwambo said most diseases which attacked plants were fungi related which could not be treated by bio-pesticides. So, he advised that the proper way to do this was “to maintain farm or garden hygiene by removing any litter and ensuring plants have plenty of sunlight and good circulation of air.”
Some farmers may be interested in organic farming, but they could be discouraged by the time a crop takes from growing to harvest, while those using improved seeds take a very short time. For instance, some maize seeds may hardly take three months from sowing to harvest.
Mbwambo said organic farming did not take too long for a plant to grow from sowing to harvest. “Improved seed if well-applied with recommended organic fertilisers will also grow fast. We encourage farmers to prepare their compost manure, and use only what is generated from domestic animals, poultry or plants.”
On the market of organic crops he said his organisation was assisting farmers to understand potential areas where they could sell their products. Farmers were also encouraged to join agricultural marketing and cooperative societies (AMCOS) and were sometimes linked directly with potential buyers.
“Farmers are trained in different methods to control insects, pests and diseases on their farms and in their homes,” he said.
On the other hand, a study published in the journal of Nature and led by William Wetzel, a Michigan State University entomologist and lead author, suggests that growing a variety of plants on a farm or in a garden attracts fewer plant-eating insects than just one type of crop.
According to Wetzel, farms can create monocultures where pests may find the perfect nutrition to be healthy and reproduce. “Planting fields with higher plant nutrient variability could contribute to sustainable pest control.” So, growing a variety of crops on one farm also serves the purpose of ‘miracle plants’.
It is advisable to smallholder farmers to grow botanical repellents on their farms if this suits their situation and may only resort to insect and pesticides where botanical repellents are ineffective. It is better to try than fail to try!
Envirocare is a Dar es Salaam-based non-governmental organisation that advocates environmental justice, human rights and gender equality and equity for all nationally and internationally.