Premium
Volunteer winter wheat: its effects and control in ryegrass seed production
Author(s) -
WRIGHT D.,
HEBBLETHWAITE P. D.
Publication year - 1983
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.1983.tb00550.x
Subject(s) - agronomy , yield (engineering) , biology , crop , perennial plant , volunteer , winter wheat , metallurgy , materials science
Summary The effects of different populations of volunteer winter wheal and their control with ethofumesate and TCA on growth, seed yield and yield components of S.24 perennial ryegrass were investigated in lield experiments in 1978 and 1979. Reductions in ryegrass seed yield due to the presence of wheat depended on the density of wheat and the number and dry weight of ryegrass tillers. The greatest percentage reduction in ryegrass seed yield occurred at high densities of wheat (300 plants m −2 ) when the number of ear‐bearing tillers and 1000 seed weight of ryegrass were reduced. When Ihe density of wheat was low (80 plants m −2 ) a smaller reduction in ryegrass seed yield occurred and the number of live wheat plants remaining gradually decreased. Within the range of wheat densities in these experiments (0–300 plants m −2 ) a 1% loss in ryegrass seed yield occurred for every 10 wheal plants m −2 present in the crop post winter. Both herbicides caused a reduction in number of ryegrass tillers during growth but, except where TCA was applied at 12 kg ha −1 in November, ryegrass seed yields were not significantly reduced (in comparison with a wheat‐free control) and were always greater than those obtained in the presence of wheat where no herbicides had been applied. Levels of volunteer infestation of 300 wheat plants m −2 were controlled with minimum risk of crop damage by applications of 6 kg ha −1 TCA in either October or November, or by application of 1–9 kg ha −1 ethofumesate in November.