Sugarcane shoot borer is a pest of major importance in all the cane growing areas of India.
The caterpillar damages 50 per cent of the shoots by tunnelling downwards into them. The pest occurs during pre monsoon and monsoon seasons. The larvae can migrate and attack many shoots. Wilted shoots can be easily pulled out.
Rotten portion of the shoot emits foul odour. Heavy infestations are favoured by poor irrigation, scanty rain fall, high temperature and low humidity.
Maximum damage
Maximum damage is caused when the crop is one to three months old. Adult moth is pale brown coloured. Female lays about 400 scale-like flat eggs in different clusters on the undersides of leaves.
Eggs hatch in five days. The larva cuts a hole in the stem above ground level and bores into the central shoot and feeds from inside. It appears pale yellowish in colour with five violet stripes of mottling brown marks.
Larval period lasts for 15 days. It pupates in the stem itself for 10 days. Total life cycle takes place in six weeks. Five generations are completed in a year. Maize and pearl millets are alternate host plants other than sugarcane.
Management
Adopt early planting during main season. Use tolerant sugarcane varieties such as CO 421, CO 661, CO 917 and CO 853.
Ensure adequate moisture to bring down the soil temperature and to increase humidity.
Remove and destroy dead shoots. Provide trash mulching up to 10–15 cm thickness three days after planting.
Earth up the crop to a height of 15-22 cm by two months after planting.
Raise intercrops like green gram, black gram and daincha with sugarcane. Sequentially release tachinid fly parasitoid, Sturmiopsis inferens at125 gravid females /ha from 30 to 50 days after planting .
Soil application of carbofuran at 33 kg/ ha or phorate 10G at 25kg/ha during planting is beneficial.
Two rounds of spraying of chlropyrifos 20EC at 1000ml or monocrotophos 36WSC or lindane 20EC at 500ml /ha or Neem Seed Kernel Extract 5 per cent during 60-90 days after planting should be done.
(N. Muthukrishnan, Professor and Head and J. Jayaraj, Professor , Department of Agricultural Entomology, Agriculture College and Research Institute, Madurai 625 104, email: agentomac@tnau.ac.in, Phone: 0452-2422956 Extn. 214)
