Bio-ecology of the cyst nematode infecting banana

Abstract

Pathogenicity of the cyst nematode on banana cv. Nendran carried out revealed that the nematode can affect crop growth and yield at lowest initial inoculum of 100 cyst3 per plant. However, the threshold level of initial inoculum of 800 to 1,000 cysts per plant the growth, yield and quality of fruits were considerably reduced. An initial inoculum of 100 to 1,000 viable cysts per plant at planting time could reduce bunch weight by 20.5?£ to 56.6?4. The nematode Infection was observed to affect quality of fruits by increasing acidity and reducing total sugars. This nematode attacks the minute tertiary feeder roots and not observed to attack the fleshy roots and rhizome portions. The attacked feeder roots turn black in colour and detach easily. The final nematode population revealed that there was significant build up in the density of population. The increase ranged from 15*59 to 35.18 per gram root and from 1,168 to 3,188 in 100 gram soil. A significant negative correlation was found to exist with plant growth parameters, bunch characteristics and root weight with the initial inoculum levels of cyst nematode population.