Species Complex and Seasonal Abundance of Panicle Pests of Sorghum, Sorghum bicolor (L.) (Moench) in North-Eastern Nigeria

Abstract

Aims: The species complex and abundance of panicle pests of sorghum was studied on eight sorghum varieties and cultivars in field trial in order identify the pest spectrum complexity on sorghum and at what time of the season they are in abundance and identify which of the sorghum varieties supports fewer pests and incorporate it in integrated pest management programme (IPM) for future studies. Study Design: The experiment was laid in a randomized complete block design (RCBD) which was replicated 3 times on 12m2 plots consisting of eight sorghum varieties and cultivars. Place and Duration of Study: The field trial was conducted in two locations at Yola, Adamawa State and Kaltungo, Gombe State in 2011 cropping season in North-eastern Nigeria. Methodology: Data was collected as from Complete Anthesis Stage (CAS) in September up to Hard Dough Stage (HDS) of sorghum development in November ending. Ten panicles /plot were sampled using transparent polythene bags. Results: During this trial, 21 pests were identified, but only 18 were common at both Yola and Kaltungo. At both locations three of the pests found were different. Insects identified in order of their abundance were: Eurystylus oldi, Sitophilus zeamais, Monolepta sp., Orius sp., Nola sorghiella, Agnoscelis versicola, Mirperus jaculus, Spilostethus sp., Nezara viridula, Campylomma sp., Achaearanea tepidoriorum, Forficula senegalensis, Apis mellifera, Messor sp., Erythroneura variabilis, Poophilus costalis, Apocrita polistes, Kraussaria angulifera, Pachnoda chordata, Mantis religiosa and Silidius apicalis. The variety that haboured the highest population of pests was SAMSORG-17 at Yola with a mean population of (609.68/10 panicles) and the least was on Tiksha-Mamza (Ex-Garkida) with a population of (153.33/10 panicles). At Kaltungo, it was SAMSORG-14 haboured the highest population of panicle insect pests (834.34/10 panicles) and the least was on Ex-Tula Farafara cultivar (182.34/10 panicles).The cultivars (Tiksha-mamza, Ex-Tula red and farafara) haboured fewer pests and are more promising than the Samsorgs (14, 17, 37, 39 and 41) improved varieties that haboured more pests. Peak population was in mid-october at soft dough stage. Conclusion: The local cultivars were more promising than the Samsorg varieties which could be improved for further studies to plant breeders and planting dates could be manipulated to escape period of high pests abundance and hence incorporated in IPM programme as a recommendation for further studies.