Effect of Environmental Factors on Seed Germination and Early Seedling Emergence of Carolina geranium (Geranium carolinianum)

Abstract

Carolina geranium (Geranium carolinianum) is an emerging invasive weed in rape and wheat fields in China. A better understanding of its germination and emergence ecology will enable the development of integrated weed control strategies. In this study, we investigated the effects of temperature, photoperiod, soil water content, salinity, and burial depth, on germination and emergence of Carolina geranium. Germination percentages were over 74% under 15/20 and 20/25 oC night/day temperature regimes. Germination rate was independent of light/dark regime. Increasing salinity reduced germination of Carolina geranium from 81.1% at 0 mM to 0% at 160 mM NaCl. Seeds germination was peaked at 50% soil moisture, but was completely inhibited at < 20% and > 90%. The seedling emergence above 82.2% was observed when seeds were placed at a depth from 0 to 1 cm, and no seedlings emerged from seeds placed at a depth of 7 cm. Current work provide the basic information to effectively prevent and control this invasive weed in Chinese rape and wheat fields.

Germinação de sementes de Amaranthus deflexus L. submetidas a diferentes condições de tempera-tura e estresse salino

“…The lowest GSI were again observed at the temperatures of 20, 40, and 30-40 °C (Figure 5C). Liu et al (2017) evaluated the influence of temperature and light on the germination and emergence of Geranium carolinianum and found that the alternating temperatures of 15/20 °C and 20/25 °C (day/night) was the most appropriate to express the maximum potential germination of this species, regardless of light. Ataíde et al (2016) found higher GSI in Melanoxylon brauna when grown at 30 ºC.…”

Managing herbicide resistance in China

“…These cultural practices disrupt the life cycles of weeds and change the surrounding weed community based on the growth characteristics of each crop (Buhler 2002). In Chinese agricultural production, crop rotation is usually adopted by rotation of a grass crop (e.g., corn, wheat, rice) with a broadleaf crop (e.g., soybean, cotton, canola), or rotation of a wetland crop (e.g., rice) with a dryland crop (e.g., wheat) (Liu et al 2018;Zhang 2003). In addition, growers often attempt to enhance crop competitiveness through the use of mulching (Yang et al 2018), allelopathy (Li et al 2019), cover crops, and full-season cultivars combined with suitable planting timing and planting density (Deng et al 2010).…”