<p>The present investigation was aimed at evaluating the effect of individual and combined treatments of defoliation and limited irrigation on stem reserve mobilization in teosinte (wild progenitor) and maize inbreds, LM 11 (relatively susceptible to water deficit) and CML 32 (relatively tolerant to water deficit). Defoliation did not affect reserve mobilization from internodes of teosinte. Mobilization remained unaltered from the basal and lower internodes of LM 11 during defoliation treatment. Mobilized dry matter and mobilization efficiency were maximum in CML 32 internodes under defoliation and limited irrigation. High sucrose synthase activity in teosinte and CML 32 grains (&gt; 75% at 0 DAIS and &gt; 25% at 8 DAIS in both genotypes under combined defoliation and limited irrigation stress as compared to control counterparts) might be related to the increased mobilization of sucrose from their internodes under stress conditions. Principal component analysis showed that alkaline invertase activity of grains, mobilized dry matter, percent mobilization efficiency, along with mobilized soluble sugars and sucrose content of upper internodes, had a significant relation with CML 32 plants subjected to individual treatment of limited irrigation and combined treatment of limited irrigation and defoliation. Linear regression analysis also showed that CML 32 and teosinte had an inherent capacity to maintain starch content under normal and stress conditions. It may be concluded that the efficient mobilization of stem reserves might be responsible for the tolerance behaviour exhibited by CML 32 plants.</p>