Seasonal changes in germinability, dormancy and viability of field bindweed (Convolvulus arvensis) seeds as affected by storage and duration

Background: Field bindweed (Convolvulus arvensis L.) is a hardy perennial weed currently threatening many agroecosystems and orchard ecosystems in China. It can be spread farther by seed with a long dormancy.Objective: This study aimed to evaluate the seasonal changes in germinability, dormancy and viability of field bindweed seeds in the unique arid environment in northwest China.Methods: Seeds were subject to burial at various depths in the field, outdoor and indoor storage, or dry-and wet-cold stratification (5 C) treatments for 12 months. Seed germinability was tested at monthly intervals.Results: No seed at 0-or 1-cm burial depths germinated in situ. Seeds buried at 3-20 cm started to germinate after 4 months, with steady increase in germination in situ over the next 7-month burial period. Some ungerminated seeds under field conditions released dormancy and could germinate ex situ under optimal laboratory conditions. The rapid dormancy release occurred under outdoor storage conditions and 13%-30% seed germinated ex situ. However, seeds from the indoor storage maintained a high level of dormancy with germination less than 12%. The dry/cold stratification was more effective in breaking seed dormancy than the wet/ cold treatment. Most of the seeds (> 87%) retained their viability during the 12-month period.Conclusions: Low temperature could partially break seed dormancy of field bindweed. The optimal emergence depth was 3-5 cm and the best time to control this weed species was from April to October. In view of the high seed viability, late season weed control is necessary to stop seedset.