The effect of environmental and management factors on seed germination and seedling emergence of Asian spiderflower (Cleome viscosa L.)

Abstract

AbstractAsian spiderflower (Cleome viscosa L.) is a fast‐growing herb found in humid and warm habitats of the Americas, Africa and Asia. It is one of the most important weeds of crop fields in Asia and Africa. The objective of this study was to determine the after‐ripening of Asian spiderflower seeds and evaluate its germination and emergence responses to various environmental (temperature, pH, salinity and water potential) and management (burial depth, flooding time and high temperature) factors. Mature seeds were collected from Kalaleh County, Iran, during October of 2015 and 2018. Seed germination increased over time and reached 77% after 209 days after‐ripening. Based on the segmented model, base and optimum temperatures for germination were 15.70–17.32°C and 31.89–34.11°C respectively. Asian spiderflower seed germination was sensitive to high levels of soil salinity and adapted to moderate‐drought conditions. Seeds germinated better at neutral and alkaline pH levels. Seedling emergence from seeds either left on the soil surface or buried at depths more than 4 cm was low, and the maximum emergence occurred in seeds buried at a depth of 1 cm. Flooding significantly reduced seedling emergence. The exposure of seeds to 82.18–87.59°C reduced seed germination by 50% and no germination occurred at 100°C. The results obtained from this study showed that several options are available for the integrated management of this weed.