Effects of spraying Metasystox* (0.05, 0.08, 0.10 and 0.15%) and Cuman-L** (0.25, 0 50, 0.75 and 1.00%) were studied on in vivo nitro-genase activity in detached root nodules of Phaseolus mungo. The enzyme activity was inhibited by 20 per cent with 0.15 per cent of metasystox on the 7th day after spraying. The plants, however, showed remarkable recovery after the growth. On the other hand, treatments of Cuman-L had little or no effect on the enzyme activity.
