Author:
FROMENT M. A.,McDONALD H. G.
Abstract
The effect of nitrogen and a plant growth regulator regime (chlormequat
chloride followed by 2-chloroethylphosphonic acid) on the crop performance
of
a hybrid (cv. Luchs) and a conventionally
bred winter rye (cv. Sentinel) were investigated in two field experiments
each
year between 1993 and
1995 at Winchester, UK. Internode length and dry weight/unit length
of
internodes was measured
in order to assess the effect of the growth regulator regime on stem structure.
Grain yields were 15%
higher in the hybrid Luchs than in Sentinel. With high levels of applied
nitrogen, both cultivars
lodged in all seasons and this was most severe in 1994 when 88% of the
crop
lodged in Sentinel and
52% in Luchs. Plant growth regulator treatment consistently reduced lodging
but
did not eliminate
it. Reductions in lodging were not always associated with an increase in
grain yield. In the hybrid
cultivar, the growth regulator treatment reduced yield in 1993 and 1995
when
2-chloroethyl-phosphonic acid was applied at GS49 and GS39 respectively,
but increased yield in 1994 when applied
at GS37. Growth regulator consistently reduced stem length, and the percentage
reduction in length
of the individual internodes within the stem was strongly influenced by
the
timing of the 2-chloroethylphosphonic acid component of the PGR treatment.
Growth regulator reduced internode
lengths by up to 25% in Sentinel and 35% in Luchs, and this was associated
with reductions in the
dry weight of internodes by up to 32% in Sentinel and 38% in Luchs. Consequently,
dry weight/unit
length of the stem was not increased by growth regulator treatment. Yield
reductions in Luchs
following growth regulator treatment may have been due to reduced stem
reserves
which have been
associated with tolerance of stress in rye. Both cultivars were highly
responsive
to nitrogen. Economic
optima varied from season to season, but they ranged over three years,
from
175–273 kg/ha nitrogen,
and were greater than the currently recommended application rates. Crop
lodging
increased with
increasing nitrogen rate even when plant growth regulator was applied and
yield penalties from lodging would have been high, if weather conditions
during grain maturity had been unfavourable.
Publisher
Cambridge University Press (CUP)
Subject
Genetics,Agronomy and Crop Science,Animal Science and Zoology
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献