Effects of Short Term Waterlogging and Nitrogen Top Dressing on Leaf Photosynthesis and Carbon Partitioning in Short Duration Pigeonpea

Accession number;05A0579915
Title;Effects of Short Term Waterlogging and Nitrogen Top Dressing on Leaf Photosynthesis and Carbon Partitioning in Short Duration Pigeonpea
Author;MATSUNAGA RYOICHI(Japan International Res. Center For Agricultural Sci. (jircas), Ibaraki, Jpn)   ITO OSAMU(Japan International Res. Center For Agricultural Sci. (jircas), Ibaraki, Jpn)   JOHANSEN CHRIS  RAO THEERTHAM P.  
Journal Title;Japanese Journal of Tropical Agriculture
Journal Code:F0874A
ISSN:0021-5260
VOL.49;NO.2;PAGE.132-139(2005)
Figure&Table&Reference;FIG.4, TBL.2, REF.27
Pub. Country;Japan
Language;English
Abstract;Apparent photosynthetic rate of leaf (Pa), stomatal conductance to water vapor (Gs) and leaf N concentration (Lf-N) of pigeonpea grown in a Vertisol field were depressed by 3-day waterlogging. Pa, Gs and Lf-N were 35,19 and 70%, respectively, of the control plants at 1 day after the end of the waterlogging treatment (DAW). Lf-N and Pa recovered simultaneously during the subsequent period of waterlogging by the of implementation of N top-dressing (50 kg ha'-1') at 1 DAW, while Gs did not recover sufficiently to the level of the control plants. Short-duration pigeonpea accumulated more starch in stems when the normal root activity was severely depressed by the waterlogging treatment. During the subsequent recovery period, the amount of starch accumulated in stems decreased gradually without N top-dressing, while more rapidly with N top-dressing. '14'C export from the '14'C-fed leaf of short-duration pigeonpea was significantly depressed immediately after 3-day waterlogging, but recovered quickly and a considerable amount of '14'C was transferred to stems soon after the release from waterlogging. In the present study we observed that short-term waterlogging reduced the Pa of short-duration pigeonpea and the early Pa depression might be caused mainly by the decrease of Gs, while the continued depression of Pa after waterlogging would be limited by Lf-N. We also concluded that short-duration pigeonpea could store photo-assimilates temporarily in stems and utilize them to survive under the unfavorable conditions such as waterlogging and that N top-dressing could promote the utilization for the recovery. (author abst.)