In my transplanted dhan the middle leaf of some tillers has dried and yellowed, and it pulls out with a gentle tug leaving the outer leaves green.
3 Answers
A dried, yellow central shoot that pulls out easily while the outer leaves stay green is the dead heart symptom of rice stem borer in the early vegetative stage. The borer larva tunnels into the base and kills the growing point, and at panicle stage the same pest causes white empty ear heads, so it is worth controlling now. Pull a few affected tillers and split the base to find the tunnel and caterpillar to confirm, or send a photo to your KVK or agri officer. Cultural steps that help are clipping the seedling tips before transplanting to remove egg masses, keeping bunds weed free, and using pheromone traps to follow the moth flights. If the share of dead hearts is high and control is needed, recommended actives include cartap hydrochloride or chlorantraniliprole, but follow the label dose, the pre-harvest interval and your local KVK recommendation and rotate the mode of action. Rice can compensate for a few dead hearts early, so base any spray on real scouting rather than panic.
I split a tiller and found the borer inside, just as described. The pheromone traps from the KVK helped me time things better.
Clipping the seedling tops before transplanting is a small effort that reduced my dead hearts noticeably this season.