Yield constraint analysis using a combination of experiments and crop growth models has been useful
for quantifying the relative role of yield-limiting factors, and for prioritizing management interventions
aimed at increasing the yields of non-photoperiod-sensitive rice grown under rainfed conditions. The
use of a systems approach for photoperiod-sensitive varieties is constrained by the lack of crop growth
models that can simulate the varieties’ photoperiod response. This study used data from the literature,
from a controlled-growth experiment, and from multi-location field experiments to determine the
photoperiod-sensitivity parameters of Jasmine rice grown in north-east Thailand, and incorporated these
in the ORYZA2000 model. Next, the model was used to analyse yield gaps by comparing yields in farmers’
fields with the simulated attainable yields with an adequate N supply (60 kg ha−1) under irrigated
conditions. The ORYZA2000 model adequately simulated growth, development, and yield of Jasmine rice
over a 0–150 kg N ha−1 range under irrigated and normal to above-normal rainfall conditions. The simulated
attainable yields ranged from 3.47 to 5.96 Mg ha−1. A simulated yield gap of 1.76 Mg ha−1 (41%)
currently exists in rainfed rice farmers’ fields. Yield gaps could be substantially reduced by 1.48 Mg ha−1
(34%) through improved N-management practices. The yield gap caused by water limitation was small
(0.02 Mg ha−1,