Tomato Nematode Diagnosis in Daloa, Côte d’Ivoire
Symptomatological studies were carried out in two tomato growing areas in Daloa to estimate and identify the associated nematode populations. Symptoms were assessed by visual observation. The soil and root nematodes were extracted by Bermann’s method and identified by observing morphological characteristics. The symptomatological study showed the presence of symptoms of plants wilting, yellowing of the leaves as well as galls on the nematodes characteristic roots. The results also highlighted diversity within the nematode population that colonizes tomato in Daloa with four genera of nematodes. The genera Tylenchus, Helicotylenchus, Partylenchus and Meloidogyne were identified. The presence of the genus Meloidogyne in all plots shows that it is responsible for the yellowing symptoms associated with root galls. These nematodes are known for their action on the formation of galls on the roots of the tomato.
The tomato (Lycopersicon esculentum Mill), Solanaceae is considered as the first vegetable after potato and the second world food resource after cereals. Its culture is adapted to very varied culture conditions. Tomato production has continued to grow in recent decades around the world; from 48 million tonnes in 1978, it rose to 124 million in 2006 (Blancard et al., 2009). In Côte d'Ivoire, the tomato sector is booming with production increasing over time. For Faostat, production was estimated at 26,235 t in 2005 and rose to 40,306 t in 2018. This crop generates income and employment for vulnerable groups and for youth (Tujague-Gibourg and Moustier, 2009).
However, tomato cultivation is faced with many parasitic constraints. Root-knot nematodes of the genus Meloidogyne are among the most important pests of tomatoes (Bissadou, 2012). Symptoms from nematode attack are characterized by the appearance of galls on the roots and reduced growth of infected plants (Cunha et al., 2018). These pests, although less integrated in research programs, are among the most important causes of crop yield reduction. It is estimated that approximately 11% of global crop losses are caused by nematodes, resulting in a crop loss of several million tonnes each year (Gregory et al., 2017).
The damage caused by Meloidogyne spp. lead to significant production losses in areas with favorable conditions (Castagnone-Sereno and Djian-Caporalino, 2011). In Côte d'Ivoire studies have been conducted on these worms which reduce tomato production. Nematode damage is difficult to quantify because it affects production by direct and indirect action.
The fight against these terrestrial parasites should begin with the information about the diversity of the tomato parasitic nematodes. The present study aims to contribute to tomato production in Daloa region through the understanding of nematode species infested with tomatoes in the area under study. This will specifically involve the causes of the damage by these nematodes and the diversity of species on the tomato crop.
Source : Tomato Nematode Diagnosis in Daloa, Côte d’Ivoire | InformativeBD
