Fig. 4. Specific activity (dpm mg^-1 nodules^-1) of ¹⁴C in different nodule size fractions as influenced by cultivar, averaged over water treatment (A) and water treatment, averaged over cultivar (B). LSDs (P < 0.05) for Fig. 4A within and between cultivars are 14 and 20, respectively, and for Fig. 4B within and between water treatments are 13 and 18, respectively.