A survey of pests of stored Ginger [Zingiber officinale (Rosc.)] in some selected markets in Rivers State, Nigeria

Two seasonal surveys were carried out in March/April and June/July, 2009 to identify insect pests of stored ginger. Dried ginger was randomly obtained from old stocks in 10 local markets within the Port Harcourt metropolis and the study was laid out in a simple CRD and each treatment was replicated 4 times. Potato dextrose agar medium was used to isolate the fungal organisms. The results show that mites were the most abundant (P,<0.05) arthropods and they were followed by Lasioderma serricorne in stored ginger during the two sampling periods. Sample collected in March/April indicated that mean number of arthropod pests that emerged from Rumuomasi market was significantly higher (P< 0.05) and the lowest number was recorded in ginger obtained from Oil Mill and Abuloma markets. Mean weight loss (g) was significantly higher in samples obtained from the fruit garden market (P< 0.05). Quantitative loss due to arthropod infestation was lowest in ginger sampled from Abuloma market. In the June/July season weight loss was significantly higher in ginger obtained from Creek road (P< 0.05) and the lowest weight loss (g) was recorded in ginger obtained from Rumuomasi and Mile 3 markets. Aspergilus flavus, Aspergilus niger, Fusarium oxysporium and Rhizopus sp. were isolated from the dried ginger samples with A. flavus having high occurences. The survey has shown that in Rivers State, stored ginger is not immune to arthropod pest infestation and fungal infection. It has also shown that seasonal variation affects the population dynamics of arthropod pests of stored ginger.