Thursday, November 6, 2008

Sugarcane early shoot borer management

Sugarcane early shoot borer management
Sugarcane is grown mainly during December - May in Tamil Nadu.
The main sugarcane planting seasons are categorized as early planting (Dec -Jan), mid planting (Feb - March) late planting (April - May) and special season (June - Sep) grown in parts of Tiruchirapalli, Perambalur, Karur, Salem, Namakkal and Coimbatore districts.
The crop grown in the special season is mostly damaged by early shoot borer and other insect pests. The pest damages mostly 1-3 months old crop.Symptoms
The caterpillars of the shoot borer cause dead hearts in young plants. The dead hearts in young plants formed at shoot stage can be pulled out easily. They emit foul odour and the canes are also damaged.
Small pale greyish brown moth lays white flat eggs in clusters of 8-60 eggs in 3 to 5 rows on the under surface of the leaf sheaths.
The larvae that hatch from the eggs in 1-6 days get scattered and enter the stem by making a hole just above the ground level. The larva may migrate and attack a number of shoots similarly. It becomes full grown in 25-30 days and pupates inside the stem. Adult moth emerges in 6-8 days. The total life cycle is completed in 35-40 days.Management
—Early season planting is ideal to evade the pest damage.
—Intercropping with green gram, black gram, daincha effectively checks shoot borer.
—Spray granulosis virus twice on 35 and 50 days after planting or release 125 gravid females of Sturmiopsis inferens/ha on 30 and 45 DAP
The virus should be applied with teepol (0.05 per cent) during evening hours immediately followed by irrigation.
A sticker like ‘teepol’ (250 ml for 500 I) can also be added to make the solution stick on to the surface of the crop.
N. Raju
D. Packiaraj
& S. Paneerselvam
TNAU, Sugarcane Research Station, Sirugamani
Tamil Nadu

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