Temperature Response of Benghal Dayflower (Commelina benghalensis): Implications for Geographic Range

Abstract

The noxious weed Benghal dayflower has become a severely troublesome agricultural weed in Georgia in the southeastern Unite States, and there are indications that it is moving northward. Benghal dayflower is glyphosate tolerant and possesses a high degree of reproductive elasticity, making it a formidable threat in many crop systems. The purpose of these experiments was to develop the first temperature response profiles for Benghal dayflower, and use them to evaluate whether temperature might limit its northward invasion into North Carolina and adjacent states on the U.S. east coast. Experiments focused on vegetative and early reproductive growth, stages considered crucial for establishment and competitiveness. Exposure to a range of aerial temperatures revealed that Benghal dayflower growth and production of aerial and subterranean reproductive structures were maximized at 30 C, with sharp declines occurring at cooler temperatures. When exposed to differing root temperatures in hydroponics, with a constant aerial temperature, Benghal dayflower growth did not show the same cool temperature sensitivity, but reproductive performance declined when temperatures decreased below about 29 C. The root temperature responses of several other weed species known to thrive in the climate of this geographic area also were determined. Growth of sicklepod, hemp sesbania, and jimsonweed was more sensitive than Benghal dayflower to cool temperatures, whereas the growth response of velvetleaf was similar. Based on the comparison of the Benghal dayflower temperature responses in controlled environments to (1) seasonal air and soil temperatures in the field, and (2) the temperature responses of agronomic weeds known to thrive in the region, it is concluded that cool temperatures will not restrain the northward spread of Benghal dayflower into North Carolina.

Seed germination in cleistogamous species: theoretical considerations and a literature survey of experimental results

“…(2001) and Sermons et al . (2008) distinguished between small and large aerial and small and large subterranean seeds, whereas Ferreira and Reinhardt (1999) and Voll et al . (2002) recognized only aerial and subterranean seeds.…”

“…In an anatomical study of the development of cleistogamous flowers, Hayden and Fagen (2016) noted that the seeds were dimorphic. Furthermore, comparison of germination of intact CH and CL seeds of this tropical/subtropical/warm temperate perennial/annual weed is based on both non-treated (Walker and Evenson, 1985b; Ferriera and Reinhardt, 1999; Voll et al ., 2002; Sermons et al ., 2008) and on treated (stored) (Kim and De Datta, 1993; Santos et al ., 2001) aerial and subterranean seeds. However, several studies on C. benghalensis have used only aerial seeds (Budd et al ., 1979; Kim et al ., 1990; Matsuo et al ., 2004; Dias et al ., 2009).…”

Temperature interactions with transpiration response to vapor pressure deficit among cultivated and wild soybean genotypes

“…In summer months in the southeastern USA, high VPD commonly coincides with high temperatures. Average daily maximum temperatures range between 30 and 32°C (Sermons et al , Purcell et al ) and occasionally reach or exceed 35°C. During a day, and sometimes from day to day, plants will experience rapid increase in temperature.…”

Environmental Influences on Growth and Reproduction of InvasiveCommelina benghalensis

“…benghalensis response to high temperature [17,35], growth processes were enhanced at the high 35/28 ∘ C temperature. However, mass of short-day plants, when compared to longday plants, was decreased by about 40% at 56 d in 35/28 ∘ C and growth was decreased 60% by short days in the slower growing plants at 30/22 ∘ C. The decreases in plant mass were accompanied by decreases in root mass (Figure 5(a)), plant height ( Figure 5(b)), and total leaf area ( Figure 5(d)) compared to plants in the long-day photoperiod.…”

“…With current warming patterns [15,16], cropping seasons can be extended, unless a counterbalancing effect is exerted by shorter day lengths. To assess responses in a worst case scenario, the environmental treatments were imposed under relatively high temperatures of 30-35 ∘ C, a temperature range common in the southeastern states in the US, when crop interference by weeds most often occurs, and a range where C. benghalensis exists [17].…”