Top-dressing N application significantly increased LI of
japonica rice primarily due to reduction of stem stiffness.
The structural carbohydrate (e.g., cellulose and lignin) of N4
internodes were responsible for higher stem stiffness, which
showed that a high accumulation of structural carbohydrate
in stem instead of NSC, exhibited the superior role for lodging
resistance in japonica rice. Top-dressing N decreased
stem physical strength due to reduction of structural carbohydrate,
especially, reducing lignin accumulation and its
related arrangement in the culm tissue and thus, resulting
in poor lodging resistance