Although the world has fully turned its attention to climate change and is continually looking for ways of slowing down its effects on humans, plants, and animals, there is another consequence sneaking up—and no one seems to notice. This consequence is nematodes! Africa’s high population growth rate and rapid urbanization, coupled with climate change, has led to the need for the intensification of agriculture, i.e., producing more from the same piece of land. However, more pests and diseases come with intensification, especially from soilborne threats, such as nematodes. The effect of nematodes on agriculture across sub-Saharan Africa (SSA) is discussed in a research review article entitled, Plant Parasitic Nematodes and Food Security in sub-Saharan Africa.
The lead authors, Danny Coyne
and Laura Cortada
, IITA Soil Health Scientists, highlight the level of damage that nematodes are responsible for in terms of yield and economic losses, up to an estimated $100 billion worldwide. These parasites are a major threat to many crops including starch staple root crops, cereals, banana/plantain, vegetables, etc. Worse, the symptoms of these nematode threats can be difficult to detect and may often be confused with symptoms of nutrient deficiency or water deficiency. Nematodes not only cause specific damage but more often form disease complexes with other pathogens and pests, exaggerating crop losses. It is unfortunate to note that although nematodes are responsible for greater losses to production than insect pests, in general, they are largely overlooked or ignored in research, policy, and farmer awareness training: “In the United States, nematodes were estimated to cause annual crop losses of US$10 billion, compared with US$6.6 billion for insect pest losses,” the authors say in the paper.
The research article, published in 2018, warns that as average temperatures rise in SSA, it is increasingly important to optimize water-use efficiency and to make better use of existing water sources to reduce the severity of the effects of nematode infection in crops.
Other recommended measures to protect against nematode threats include the use of healthy nematode-free planting material, resistant varieties, and crop rotations to suppress nematode infestation.
Farmers’ awareness and skills are equally important in minimizing nematode infestation and yield losses.
The authors also call for policies that more readily facilitate the registration of new, biologically based products, as well as considering nematode resistance when using newer breeding tools such as biotechnology.