Received: July 16th, 2022 ; Accepted: September 8th, 2022 ; Published: September 12th, 2022 ; Correspondence: [email protected] atmospheric carbon dioxide (CO2) concentration is increasing and the on crop
production needs to be investigated. A pot experiment was conducted in open top chambers
(OTC) to determine the response of rice to elevated CO2 (eCO2) under varying time of nitrogen
(N) application. The results revealed that photosynthesis, root and shoot dry matter production,
yield components and nutrient absorption were favored at eCO2 when N applied up to flowering
stage (FT) of rice. However, the N application up to FT of rice also significantly improved percent
filled grain, reduce spikelet sterility and rice yield increased by 18 to 20% under eCO2. Rice plant
absorbed higher amount of Zn, Ca, Mg, and Fe at eCO2 when N was applied up to FT. Amylose
was higher but protein percentage was lower at eCO2. These results indicate that to maximize rice
yield under eCO2, it is important to supply N up to FT of rice in order to increase grain fertility
and reduce spikelet sterility