Microbes, New Weapon Against Agricultural Pests in Africa

  • 25th April 2017
  • by secretary
10 April 2017. BULAWAYO, Zimbabwe,  (IPS) – Microscopic soil organisms could be an environmentally friendly way to control crop pests and diseases and even protect agriculture against the impacts of climate change.

Researchers at Auburn University have worked on beneficial soil bacteria/microbes, specifically plant growth-promoting rhizobacteria (PGPR). The soil dwelling bacteria that colonize plant roots have beneficial effects of increasing plant growth and enhancing the ability of plants to fight off herbivorous insect pests such as the beet armyworm-Spodoptera exigua and the fall armyworm Spodoptera frugiperda to which they have a direct toxic effect.

“Research from our labs at Auburn University has shown a great potential in microbes for helping fight pests- and we have done some research on fall army worm that are pests in turf grass,” Dr. Esther Ngumbi, a post-doctoral researcher in the Department of Entomology and Plant Pathology at the Auburn University in Alabama, United States.

First reported in Sao Tome and Principe in January 2016, the crop-eating pest has affected thousands of hectares of crops in Namibia, Malawi, Mozambique, South Africa, Uganda, Zambia and Zimbabwe to date. The pest which is difficult to control with one type of pesticide can cause extensive crop damage of up to 73 percent in the field. It also attacks non-cereal crops including potato, groundnut, spinach, tomato, cabbage, soybeans, cotton and tobacco.

Poor identification of the pest delayed response to the outbreak in November 2016 because the pest has never been encountered before in Southern Africa. Everyone was classifying it [FAW] as a stalk borer or the American bollworm but they were all wrong. This new pest has now been identified as the fall armyworm and people started extensively using pesticides – some of them not yet registered.  

Chemicals are a quick fix and short-term solution to insect pest control and also kill the predators of the pests. This affects the environment and also birds who feed on caterpillars making it important to focus more on alternative ways through biological solutions such as Integrated Pest Management, crop diversification and  intercropping.  Dr. Christian Thierfelder, Senior Cropping Systems Agronomist at the International Maize and Wheat Improvement Center (CIMMYT), Southern Africa Regional Office,