The bushy appearance with dead heart in sugarcane at 6^th inter-node is due to

The bushy appearance with dead heart in sugarcane at 6^th inter-node is due to Top borer.
Dead heart in sugarcane is a deformed stunted plant of certain crop grasses caused by borer attack on the region immediately behind the growing bud and characterized by bushy blanched distorted growth beyond the damaged area.
Presence of the reddish mid-rib tunnel on the crown leaf indicates top-borer infestation. Larva eats away the growing point and thus slender dead heart is formed.