Premium
Nitrogen studies in Lolium perenne grown for seed. IV. Response of amenity types and influence of a growth regulator
Author(s) -
HAMPTON J. G.,
CLEMENCE T. G. A.,
HEBBLETHWAITE P. D.
Publication year - 1983
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/j.1365-2494.1983.tb01627.x
Subject(s) - lolium perenne , tiller (botany) , perennial plant , growth regulator , agronomy , biology , nitrogen , yield (engineering) , cultivar , competition (biology) , horticulture , chemistry , ecology , materials science , organic chemistry , metallurgy
In field trials in 1979–81, perennial ryegrass cultivars Royal and Majestic (amenity) and Morenne (agricultural) produced maximum seed yields at levels of applied N ranging from 40 kg ha −1 to 160 kg ha −1 . Available soil N levels were estimated at 55 kg ha −1 ; hence maximum seed yields were obtained at total nitrogen levels of 95–135 kg ha −1 in Royal, 95–215 kg ha −1 in Morenne, and 175–215 kg ha −1 in Majestic. Applied N at rates above 120 kg ha −1 either reduced or did not significantly increase seed yield, decreased seed numbers per unit area and decreased spikelets per tiller and seeds per spikelet. The use of a growth regulator increased seed yields by preventing lodging, but did so irrespective of nitrogen application rate. It is suggested that failure to increase seed yield at high N rates is a result not of poor pollination because of lodging, but seed abortion as a consequence of competition for assimilate supply by secondary vegetative tillers.