Infestation patterns of the coconut mite (Eriophyes guerreronis Keifer) and resulting yield loss in the South Western Region of Bangladesh (original) (raw)

2013, International Journal of Biosciences (IJB)

In the experiment, coconut was collected randomly from Khulna, Satkhira and Bagherhat districts of Bangladesh and categorized into five grades based upon infestation pattern of coconut mite on coconut. The experimental treatments of factorial experiment consisted of three locations (L1= Khulna, L2 = Bagherhat and L3 = Satkhira); two varieties (V1= Green and V2= Brown) and five grades on the basis of mite infestation which are G0 = nuts with no mite damage, G1 = nuts with 1-29% surface area damage, G2 = nuts with 30-59% surface area damage and less than 20% reduction in size, G3 = nuts with 60-80% surface area damage, 20-30% reduction in size and G4 = nuts with over 80% surface area damage with 30% reduction and often greatly deformed. From the study it was found that most of the cases highest values were recorded from G0 and the lowest values were recorded from G4. It was found that the dry weight of copra was significantly varied among the different grades. The highest dry weight (164.33g) was recorded from G0 and the lowest (386.94g) from G4. Among the location, the fruits collected from Khulna and Satkhira gave highest values and the lowest value was recorded from the fruits of Bagherhat district. From the experiment it was found that water loss was observed about 0, 5.5, 34.19, 50 and 62.59% in damage categories of G0, G1, G2, G3 and G4, respectively. For the copra yield considerable loss was occurred that ware 0, 13.22, 24.90, 38.00 and 52.72% in damage categories G0, G1, G2, G3 and G4, respectively. Observed coconut shell losses were 0, 7.28, 15.32, 24.42, and 37.17% corresponding to damage categories G0, G1, G2, G3 and G4, respectively. Due to mite infestation about 37.17% coconut shell loss, 62.59% water loss and 52.72% copra yield loss was occurred when nuts with over 80% surface area damaged with 30% reduction of size.