Effect of N application on its utilization and gaseous exchange in cat tail (Typha elephantina) under waterlogged condition

Abstract

The cat tail (Typha elephantina), a non-food commercial crop grows as an emergent hydrophyte in tidal waterlogged areas. Its leaves are used for preparing mats and used as roof top and wall partition. Typha sp. has been found to be efficient accumulator of N from sediment under waterlogged condition. The N utilization mainly through nitrate reductase (NR) activity was studied in Typha with four levels of N fertilizers i.e. 0, 30 and 60 and 90 kg ha-1 applied at three stages of plant growth i.e. basal, 3 and 6 month after planting. In general, there was reduction in NR activity under waterlogged condition in Typha. But application of @ 90 kg ha-1 maintained high NR activity when it was applied as basal stage. Basal application of N was found better than its application at 3 or 6 month stage of crop growth. The higher leaf NR activity at 60 and 90 kg ha-1 N application level suggested better N utilization under waterlogged environment. The photosynthesis rate showed significant increase with higher N application concomitant with greater stomatal conductance (r = 0.84* * ; n = 12). There was significant increase in leaf yield when N was applied @ 90 kg ha-1 N level as basal dosage as compared to later stage (3 or 6 months) of crop growth. The highest fertilizer use efficiency (kg dry leaf kg-1 applied N) was also found at 90 kg N ha-1 as compared to 30 or 60 kg ha-1 N level, which corroborated superior N fertilizer utilization ability of Typha under waterlogged condition.