Effect of temperature and photoperiod on the phenological development of wild mustard ( Sinapis arvensis L.)

Abstract

The development of mechanistic weed models focuses on determining the outcome of weed–crop interference. Phenological development is a major factor determining the outcome of weed and crop competition. The influence of temperature and photoperiod on phenological development of wild mustard ( Sinapis arvensis L.) was studied in growth cabinets. The life cycle of wild mustard was defined in terms of biological days (Bd: chronological days at the optimum photoperiod and temperature). Wild mustard was a long-day species adapted to a wide temperature range of 1.5–48°C. Four phases of development of wild mustard were described: (1) a juvenile phase of 12.7 Bd; (2) a photoperiod-sensitive inductive phase of 6.2 Bd; (3) a photoperiod-sensitive post-inductive phase of 12.8 Bd; (4) a photoperiod-insensitive phase of 33.9 Bd. When effects of photoperiod on rate of development were normalized across phases of development, photoperiod sensitivity did not vary among phases of development. Interpretation of constant sensitivity to photoperiod will simplify simulation of weed phenology in mechanistic models.