Investigating botanical pesticides in Southern Africa

 

Tanzania is among the largest producers of common bean (Phaseolus vulgaris) in the world. Common beans are rich in protein and provide many nutrients that are considered key elements for mental development. Insect pests are one of the most common factors affecting bean production and due to the severity of insect pests affecting beans, many African farmers increasingly resort to frequent use of commercial synthetic pesticides. Researchers within CCRP’s botanical pesticides project are working to eliminate knowledge gaps that prevent the widespread uptake and use of botanical pesticides as an alternative. Research on the efficacy of botanical pesticides under field conditions, their economic viability, best application practices, and impact on beneficial organisms have been published.

The team focused on studying extracts made several abundant weed species found the area, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina, Lippia javanica, Bidens pilosa, and Lantana camara and if the extracts offered effective control of key pest species on common bean plants. Among the of array of interesting results the team has shown that the plant pesticide treatments had significantly lower effects on natural enemies and that plant pesticide treatments were more cost effective to use than the synthetic pesticide. The team also identified T. vogelii as a good candidate for development in to a natural pesticide as a non-food cash crop. Publications are linked below.

  • Mkindi, Angela, Nelson Mpumi, Yolice Tembo, Phillip C. Stevenson, Patrick A. Ndakidemi, Kelvin Mtei, Revocatus Machunda, and Steven R. Belmain. 2017. “Invasive Weeds with Pesticidal Properties as Potential New Crops.” Industrial Crops and Products, June. doi:10.1016/j.indcrop.2017.06.002. https://doi.org/10.1016/j.indcrop.2017.06.002
  • Mkenda P, Mwanauta R, Stevenson PC, Ndakidemi P, Mtei K, Belmain SR (2015) Extracts from Field Margin Weeds Provide Economically Viable and Environmentally Benign Pest Control Compared to Synthetic Pesticides. PLoS ONE 10 (11): e0143530. doi:10.1371/journal.pone.0143530. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4658159/

 

Photo above: Farmers, who have intercropped maize and beans are receiving a short training on the use of botanical pesticides. They are participating in the trial of mixing measured powders in a water that has 0.1% soap by practicing measuring volumes of water and soap as well as weighing plant  powders. Courtesy of Angela Mkindi, botanical pesticide project.