Top Borer Control

Symptoms

Look for dead hearts in the top of grown canes that cannot be pulled out easily, unlike early shoot borer. Rows of small bore holes appear in a straight line across young top leaves, called shot holes, and the growing point is killed so side shoots grow giving a bunchy top appearance.

Damage

Top borer (Scirpophaga excerptalis) bores into the top growing point of the cane, killing it and causing dead hearts and bunchy tops. It attacks at several stages through the season and stops cane growth, reducing both cane length and weight. Heavy infestation can cause significant yield and sugar loss.

Organic & cultural control

Release the egg parasitoid Trichogramma chilonis and conserve the specific parasitoid Isotima javensis where present. Remove and destroy young shoots showing dead hearts along with the larvae. Detrash lower leaves and avoid excess nitrogen. Use light traps and pheromone traps for monitoring adult moths through the season.

Chemical control

Where the pest crosses the threshold, soil application of recommended systemic granular insecticides such as chlorantraniliprole near the base followed by irrigation can give good control. Time applications to the early generations for best effect. Always read and follow the product label, observe the pre-harvest interval, and consult your KVK or a qualified agronomist before applying.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Plant healthy setts of less susceptible varieties on time and keep balanced fertiliser, avoiding excess nitrogen. Detrash regularly, remove and destroy dead heart shoots, and avoid carrying over heavily infested ratoons. Monitor with light and pheromone traps and release Trichogramma against early generations.