Marjan Diyanat
Abstract
Polygonum is one of the most widespread weeds in the world. To determine the best dormancy- breaking treatment, five dormancy-breaking treatments consisted of 10 and 20 min soaking in sulfuric acid, 0.2% nitrate potassium, wet chilling and 200 ppm gibberellic acid were studied. At second experiment germination ...
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Polygonum is one of the most widespread weeds in the world. To determine the best dormancy- breaking treatment, five dormancy-breaking treatments consisted of 10 and 20 min soaking in sulfuric acid, 0.2% nitrate potassium, wet chilling and 200 ppm gibberellic acid were studied. At second experiment germination percentage was evaluated under different alternating temperature and light regimes. seeds of ten populations were exposed to three levels of light (24 h darkness, 16 h light/8 h darkness and continuous light) and five alternating day/night temperature regimes 15/5°C, 20/10°C, 25/15°C , 30/20°and 35/25 ºC for 21 days. For third experiment, seven depths ( 0, 2, 4, 6, 8, 10 and 12 cm) were investigated. Results showed that best treatment for dormancy breaking was wet chilling for Prostrate knotweed and Lady’s thumb and sulfuric acid 20 min for Wild buckwheat. Germination of Polygonum species seeds occurred over a wide range of alternating temperatures but there were inter- and intraspecific differences in optimal temperature. Wild buckwheat was not dependent to light for germination. Seedling emergence decreased exponentially with increasing burial depth with highest emergence for unburied seeds. The influence of burial depth was extremely dependent on population. High seedling emergence of Prostrate knotweed and Lady’s thumb on the soil surface could be suggesting light requirements. Therefore, spreading of these species would be higher in fields with no-tillage or minimum-tillage practices. Increasing of tillage depth could be an effective weed management strategy to reduce seedling emergence of Prostrate knotweed and Lady’s thumb.
