Field evaluation of insect pests and pathogens associated with Sesame cultivated in the Niger Delta of Nigeria

Field evaluation of insect pests and pathogens associated with sesame cultivated in the Niger Delta region of Nigeria was conducted to provide baseline information on their status. The experiment was laid out in Randomized Complete Block Design. Herein, sesame seeds were obtained from the Jos and Maiduguri main markets. These were sown, then data were collected on insect species beginning three weeks after sowing (WAS) for six weeks and identified to species levels. At 10 WAS, plant parasitic nematodes (PPNs) were extracted from both root and soil samples in the rhizosphere of sesame, using the modified Baermann method. Plant parasitic nematodes were identified to generic level. Infected plant parts from field were thoroughly washed, disinfected and plated on PDA, and subsequently incubated at 25 ± 2 °C. Fungal pathogens were isolated, identified and checked for their viability and purity. Data obtained were subjected to both parametric and none parametric analyses. Insect species collected included Leptaulaca fissicolis, Gryllus bimaculatus, Apogonia nitidula, Trilophida conturbata, Elis sp. amongst others. A total of six genera of PPNs, Helicotylenchus, Pratylenchus, Scutellonema, Gracilacus, Meloidogyne and Tylenchus were associated with Sesame. Gracilacus and Pratylenchus had the highest population in soil (37.5%) and roots (37.5%). Three fungal isolates, namely, Fusarium oxysporum, Fusarium solani and Trichoderma sp, were consistently isolated from the plant parts - with Fusarium oxysporum and Fusarium solani being pathogenic. Knowledge of these insect pests and pathogens will aid in their management.