The threat of root‐knot nematodes (Meloidogyne spp.) in Africa: a review

Abstract

Meloidogyne species pose a significant threat to crop production in Africa due to the losses they cause in a wide range of agricultural crops. The direct and indirect damage caused by various Meloidogyne species results in delayed maturity, toppling, reduced yields and quality of crop produce, high costs of production and therefore loss of income. In addition, emergence of resistance-breaking Meloidogyne species has partly rendered various pest management programmes already in place ineffective, therefore putting food security of the continent at risk. It is likely that more losses may be experienced in the future due to the on-going withdrawal of nematicides. To adequately address the threat of Meloidogyne species in Africa, an accurate assessment and understanding of the species present, genetic diversity, population structure, parasitism mechanisms and how each of these factors contribute to the overall threat posed by Meloidogyne species is important. Thus, the ability to accurately characterize and identify Meloidogyne species is crucial if the threat of Meloidogyne species to crop production in Africa is to be effectively tackled. This review discusses the use of traditional versus molecular-based identification methods of Meloidogyne species and how accurate identification using a polyphasic approach can negate the eminent threat of root knot nematodes in crop production. The potential threat to Africa posed by highly damaging and resistance-breaking populations of 'emerging' Meloidogyne species is also examined.

Plant parasitic nematode assemblages associated with sweet potato in Kenya and their relationship with environmental variables

“…Due to its capability of rapidly spreading to and colonizing new localities (Bebber et al 2014)) and wide host range, root knot nematode (RKN, Meloidogyne spp), is ranked as the most economically damaging (Jones et al 2013). Twenty Meloidogyne species occur in Africa with M. incognita, M. javanica and M. arenaria being the most prevalent (Onkendi et al 2014).…”

Climate change impacts and adaptation in South Africa

“…Impacts on key agricultural pest species are a critical concern, with a number of key pests and pathogens projected to increase net range suitability in South Africa and on the continent more broadly. [61][62][63] Water Hydrological models using downscaled climate projections have been the primary means of assessing sectoral impacts. 29,[64][65][66] The hydrological system is dynamic, and changes in climate may result in unanticipated hydrological responses, possibly beyond the ranges for which the models' ability to represent processes has been tested.…”

Fungal root endophytes of tomato from Kenya and their nematode biocontrol potential

“…In particular, the plantparasitic root-knot nematode Meloidogyne incognita (Kofoid and White 1919) Chitwood 1949, is considered a major problem in the tropics and subtropics, such as the East African rift valley areas of Kenya and Ethiopia (Onkendi et al 2014). Therefore, increase in tomato yield is partly dependent on proper nematode control.…”