Use of eco-friendly and low cost locally available botanical extracts for the control of common bean pests in Uganda

Common bean is the most important grain legume consumed in Uganda. Known as the “meat for the poor”, the crop is the most important source of protein to the Ugandan population providing about 45% of the total dietary protein.  Despite its importance, its production has remained very low. Pests of common bean such as Ootheca spp, Ophiomia spp, Aphis fabae, Bemisia tabaci, among others are the most challenging factors responsible for low yields of common bean in Uganda. In an attempt to reduce the effect of pests and diseases, farmers use chemical insecticides. However, the use of chemical insecticides is associated with adverse effects to the environment such as killing of non-target organisms and offer health threats to the farmers. Additionally, the use of chemical insecticides is expensive and therefore results into low profits from bean farming. This is worsened by the fact that Ugandan farmers are resource poor farmers who lack enough capital to invest in the use of chemical insecticides despite their adverse effects. The use of botanical extracts to control bean pests in Uganda will provide an opportunity for the resource poor farmers to control bean pests and obtain high yields while maintain the quality of the environment. Farmers in Uganda lack knowledge of these substances mainly because they have not been promoted by researchers and agricultural extension agents. In neighboring countries like Tanzania, these botanicals have been found to control bean pests (for example, bean leaf beetles). Therefore, validating these botanicals in Uganda, and promoting their use through farmer training and advocacy will help bean farmers reduce on the use of chemical insecticides, produce food that is free form pesticide residues and hence safe for human consumption, reduce on the effect of chemicals in the environment, and maximize profits resulting from low costs of pest control.

Botanical extracts will be obtained from available plant species with insecticidal properties such as Azadirachta indica, Phytolacca dodecandra, Capsicum spp, among others. Additionally, urine from animals will be included. Formulations of such concoctions will be prepared and applied to control bean pests in a farmer participatory research with selected bean growers on their fields as model farmers. Farmers will learn how to prepare and apply these substances. Later on, community meetings will be held where we shall pass on the knowledge to the target communities using the model farmers. This will therefore build capacity of farmers to control bean pests using a few model farmers. The activities will be carried out for one year (two consecutive growing seasons) and by the end of this time, farmers will be equipped with the necessary skills to control bean pests using botanicals. For the beginning, the target shall be the Northern region of the country which is the most infested by bean pests. Subsequently, given the availability of funds, the project will be extended to other parts of the country. The skills and knowledge can be passed on from farmer to farmer even after the project has ended.

Chalres Halerimana, Uganda

79 comments

  1. Charles, thank you for the piece and tireless efforts towards this research. It’s the way to go. Do we have it on market already?

    Liked by 1 person

    1. On the Ugandan market, there is one commercialized botanical pesticide called Nimbecidine. It is made from Neem tree and is avilable for use. However, the cost is similar to that of inorganic insectcides and is not accesible to farmers in most regions. We want to explore different insectcidal plants in this study and have even cheaper options than Nimbecidne that farmers themselves can locally make for their pest soulutions.

      Like

  2. This is a very important research innovation for the country.The use of inorganic chemical pestcides in beans is almost lendering beans useless. This is because children are nolonger suffering from protein deficiencies but rather from chemical intoxification and sometime poisoning as a result of consuming intoxicated beans. We need plant extract based pestcides indeed.

    Like

    1. Oh…This is deep now!!
      Pesticide residues affect all people exposed to them. Residues in food, therefore, affects everyone that consumes an item contaminated with the insecticides. It is probably more pronounced in children because, at the young age, their immunity is still weak but in the long run if this continues, even adults who eat of those beans will definitely have to suffer the consequences. There is a need to reduce the use of chemical insecticides but also now this calls for proper protective mechanisms for safety.
      Thank you Papius.

      Like

  3. it’s a nice innovation for our farmer, I pray that you succeed especially through getting funds to kick start it

    Like

  4. This is so good for this country, beans form one of the major staple foods for the populations in Uganda

    Like

  5. This is great work Charles. I like the idea that your focus was on beans which is the staple food for the people of East Africa. This means masses will benefit from this brilliant idea. Keep it up. The sky is no longer the limit.

    Like

  6. Controlling pest in beans is a major challenge due to drawbacks associated with the cultural and chemical methods. Among these limitations are for example issues with human and environmental safety, polyphagous nature of pests and the lack of resistance genes (R-genes) in cultivated crops or their related germ pool. This triggers the innovative use of plant extracts as alternative control strategy for sustainable agriculture. In fact, research has demonstrated that extracts from certain crop species contain molecules that trigger natural immune system of the plant. Application of extracts alerts the plant to recognize and react to pests by activating defence responses which are expressed and conditioned in a variety of mechanisms. This puts the plant in ‘primed’ state, meaning that it is able to trigger more robust and long lasting resistance upon pest attack. Examples of induced defence responses include signal transduction pathways leading to production and secretion of defence molecules including reactive oxygen species (ROS), phytoalexins biosynthesis, cell wall strengthening, callose deposition, synthesis of defence enzymes, production of pathogenesis-related (PR) proteins and production of phytohormones.
    All these mentioned responses only kill the plant invaders, meaning that beneficial organisms will not be affected since these extracts don’t kill the pest directly but rather induce natural host resistance. However, this might be hypothetical but can be confirmed by bioassay experiments.
    I am therefore grateful that Charles has come up with this innovative idea for sustainable crop protection. Indeed, this strategy can be applied in other crops to control their respective devastating pest.
    Good luck Charles!

    Like

Comments are closed.