ISSN:
1573-5036
Keywords:
Cicer arietinum L.
;
Chickpea
;
Dinitrogen fixation
;
Nitrate
;
Nitrogen assimilation and distribution
;
Rhizobium
;
Temperature interactions
;
Yield
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Nodulated chickpea plants were grown in pots in a glasshouse programmed to simulate either hot (32.5°C day/18°C night) or warm (25°C/18°C) thermal regimes characteristic of those experienced by crops grown in different seasons or locations in the semi-arid tropics. The plants were irrigated with nutrient solution either devoid of inorganic nitrogen or containing 0.71, 1.43 or 2.86 mM nitrate. Hot days delayed nodulation, decreased specific dinitrogen fixation (acetylene reduction) activity and hastened nodule and host plant senescence compared with these symbiotic attributes in warm days. The effects of nitrate on acetylene reduction activities plant−1 were mediated primarily through changes in the respective rates of nodule establishment, growth and senescence. Nitrate at 0.71 or 1.43 mM stimulated early nodulation and nodule growth but at 1.43 and 2.86 mM it hastened nodule senescence compared with plants totally dependent on symbiotic dinitrogen fixation, particularly in the hot regime. Larger concentrations of nitrate decreased not only symbiotic N2 assimilation during seed filling but also the total N assimilated during the same period. Plants given 2.86 mM nitrate, in either the warm or hot regime, assimilated substantially larger amounts of total N than those dependent on nodules, and then mostlybefore the seed filling period. However, nodule-dependent plants assimilated about 50% of their total Nduring the seed filling stage and the partitioning of N to fruits, stems and roots in mature plants was similar irrespective of thermal regime or nitrogen nutrition. The implications of these data for the nitrogen nutrition of chickpea crops are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02184299
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