Alleviation of dark induced effects of nodule functioning by sucrose and succinic acid spray in Cicer arietinum L.

Prolongation of the natural dark period to 18, 42 and 66 h resulted in a marked decrease in nitrogen fixation (acetylene reduction activity). Dark treatment also resulted in a considerable decrease in nodule respiration and their carbohydrate content (total soluble sugars, reducing sugars and starch). Spraying dark treated plants with sucrose (30 mM and 60 mM) and succinic acid (10 mM and 20 mM) alleviated the adverse effect of dark treatment on nitrogen fixation and other parameters to some extent. The most effective treatment was found to be spray with 60 mM sucrose followed by 20 mM succinic acid.