Nematode infestation is one of the major limiting factors in banana production. Burrowing nematode, root-lesion nematode, spiral nematode and root-knot nematode are the major nematodes associated with banana.

These cause extensive root and corm damage leading to 20-50 per cent fruit yield loss. Commercial banana cultivars like Nendran, Robusta, Grand Naine, Ney Poovan, Poovan and Rasthali are often infested by these nematodes.

Dark lesions

The nematodes penetrate the roots and destroy the plant cells. This leads to dark lesion on root surface. Under severe infestation the root turns black. These nematodes can migrate from infected roots to other parts of the plant.

Adult females lay 200-300 eggs. They damage the xylem vessel and affect the uptake of water and nutrients.

Research on nematode management in banana is in progress for more than three decades through All India Co-ordinated Project on Tropical Fruits (AICRP-TF) at the Tamil Nadu Agricultural University (TNAU), Coimbatore. The following are some management options that help to overcome the infestation.

Summer ploughing and exposing the soil to sunlight prior to planting for about two months. Selection of healthy sucker from nematode-free plants.

Grow marigold

Growing Sunhemp or marigold in and around the basin of plants during early stages of crop and incorporating their biomass one month later can reduce nematode build up.

Press mud application at rate of 15 tonnes per ha (5 kg/pit) or neem cake 1.5 tonnes per ha (500 g/pit) during planting can also help to avoid nematode build up.

Application of farm-yard manure at 10 kg per plant 60 days after planting. — Rotating banana with paddy.

Application of Pseudomonas fluorescens liquid formulation at 4 lit/ha at two, four and six months after planting through drip system will help.

(E.I. Jonathan, Prof and Head, Department of Fruit Crops and N. Sreenivasan, Assistant Prof, department of Nematology, TNAU. email: seeni_nema@yahoo.com and eijonathan@yahoo.com, phone: 09865724277.)