The entry of banana weevil, a common pest, in tribal areas across the Petchiparai dam has become a cause of concern for both farmers and officials of the horticulture department as these areas had once been totally free from the pest.
‘Nenthiran’ and red bananas planted in these areas have become its victims. “Commonly known as stem borer, the pest could wreak havoc on banana crop and contribute to drastic decline in banana cultivable area.” said Surendran Joseph, Assistant Director, Horticultural Department in Kanyakumari district, who identified the pests during a field visit.
Mr Joseph said when he received complaints of banana stems bending over and collapsing at Thatchamalai during the flowering stage, he was under the impression it could be due to some fungus attack.
“Even last year there was no incidence of this pest. But now I am surprised to find that it is the handiwork of the stem borer,” he said. Even though the problem was prevalent in Kanyakumari district, particularly in Vilavancode taluk, the borer could not make a foray into tribal areas all these years.
He felt the weevil, which could reach 10-16mm length with a hard-shelled and curved snout, could have invaded the area along with banana suckers brought from outside for planting.
The damage is caused by the grub (larva of the weevil), which makes tunnels as it feeds on the corm and root stock. The tunnels encourage fungal infection, ultimately reducing it into a black mass of rotten tissues. This hinders root initiation and sap flow to the plants.
“The infection will result in yellowing of leaves and withering; particularly, young suckers show symptoms of wilting. In older plants, growth is retarded. In case of severe infection, plants produce small bunches and are easily blown over by wind,” he explained.
Mr Joseph said the pest could be controlled through crop rotation, drip irrigation, selection of healthy planting material and keeping the garden clean from weeds and crop debris. “Uproot the infested plant, chop it into pieces and burn them. Removal of pseudo stem below the ground level,” he said, and advised farmers to avoid planting susceptible varieties such as robusta and red banana
He said if the planting material is suspected of being infested, the suckers should be trimmed on all sides so as to eradicate the presence of eggs and grubs.
