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Dry Matter Production, Yield, and Allocation of Carbon‐14 Assimilates by Wheat as Affected by Nitrogen Source and Salinity
Author(s) -
Botella M. A.,
Cerdá A. C.,
Lips S. H.
Publication year - 1993
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1993.00021962008500050016x
Subject(s) - salinity , agronomy , sowing , dry matter , nitrogen , nutrient , nitrate , biomass (ecology) , ammonium , ammonium nitrate , yield (engineering) , biology , chemistry , ecology , organic chemistry , materials science , metallurgy
Wheat ( Triticum aestivum L.) growth is affected by both salinity and the type of N fed to the plants. The objective of this research was to determine the effect of salinity applied at different stages of the life cycle of wheat plants supplied with either NH 4 or NO 3 on growth, yield, and translocation of photosynthates. Plants were grown in sand culture irrigated with nutrient solution until maturity. The nutrient solution contained 4 m M N, either as (NH 4 ) 2 SO 4 or Ca(NO 3 ) 2 . Salinity (60 m M NaCl) was applied to the nutrient solution at 19, 70, and 92 d after sowing. Some of the plants received 14 CO 2 pulses 100 d after sowing, and 14 C distribution in each plant part was determined 24 h later. Dry biomass production and grain yield were reduced when salinity was applied 19 d after sowing (beginning of the vegetative stage), whereas no effect of NaCl was observed when salinity was applied later. Ammonium‐fed plants always produced more tillers and spikes than NO 3 ‐fed plants. Total grain yield was similar with plants growing in either N form. Nitrate‐treated plants produced fewer, but heavier, spikes due to a larger number of grains per spike than NH 4 ‐fed plants. Ammonium‐fed plants showed a preferential allocation of 14 C‐assimilates to young developing tillers. Nitrate‐fed plants, under similar conditions, allocated assimilates preferentially to grain. Salinity enhanced translocation of assimilates to the spikes when plants were grown with NO 3 .