Fig. 1 Relationship between aboveground N content at maturity and grain yield for nine sorghum hybrids grown under terminal water deficit (r = 0.83, n = 21, P < 0.001). Total N content was the sum of green leaf N content, dead leaf N content, stem N content, and panicle N content. In the case of AQL41/R69264, AQL41/RQL36, AQL41/RQL12 and A35/RQL12, at least one of these components was missing, preventing the calculation of total N uptake for those samples. Hence, there are only 21 points on the graph out of a potential of 27 points