A superweed in the making: adaptations of Parthenium hysterophorus to a changing climate. A review

Abstract

Parthenium weed (Parthenium hysterophorus L.) is a globally invasive plant with significant negative impacts on the environment, agriculture, economy, and health. This invasion problem is likely to be exacerbated by climate change. Elevated atmospheric carbon dioxide concentration ([CO 2 ]), high ambient temperatures, heatwaves, and droughts will facilitate the establishment, range expansion, and interference potential of this invasive species while making its management more difficult. Here, for the first time, we review the potential impact of climate change elements on parthenium weed biology and management at regional and global levels. We establish that (1) parthenium weed plants morphologically and physiologically adapt to sustain or promote their growth, fecundity, competitive ability, and allelopathic effect under most climate change scenarios; (2) climate change elements can reduce the relative vigor of neighboring plants, especially C4 grasses, in competition with parthenium weed, providing this invasive species a competitive edge; (3) elevated [CO 2 ] has the most pronounced positive effect on parthenium weed performance compared to other climate change elements; (4) the efficacy of a widely used herbicide, glyphosate, may be reduced on parthenium weed grown under elevated [CO 2 ]; (5) mixed effects have been reported for biological control agents, with some losing ground, while others are maintaining or improving their efficacy; and (6) a greater risk of spread and range expansion under sustained climate change will pose greater challenges for management in natural and managed ecosystems. There has been a disturbing transition of this weed from noncropped landscapes to agroecosystems in response to recent climatic and land use changes. All evidence presented in this review suggests that the situation will be greatly aggravated if drastic management interventions are not implemented. Therefore, the research, policy, and outreach focus must be revisited and revamped considering the impacts of climate change to develop pragmatic solutions to combat this "superweed".

Impact of Climate Change on Dryland Agricultural Systems: A Review of Current Status, Potentials, and Further Work Need

“…They reported that climate change favors the expansion, growth and multiplication of wheat pests. Furthermore, climate change opens new geographic windows for weed infestations (Mao et al, 2021;Vilà et al, 2021), insect biodiversity (Raven & Wagner, 2021) and disease outbreaks (Chaloner et al, 2021) across Fig. 6 Interactive effect of elevated CO 2 , temperature, and drought on soil organic carbon the globe.…”

Biological Response of Invasive Parthenium Weed to Elevated Concentration of Atmospheric Carbon Dioxide and Soil Salinity

“…Parthenium weed (Parthenium hysterophorus L.) belongs to the family Asteraceae and is one of the most invasive plant species with an ever-expanding introduced range around the world [14]. It is an aggressive, herbaceous weed with multiple morphological and physiological characteristics making it highly adaptable to various biotic and abiotic stresses [14][15][16]. Massive infestations are often observed on vacant land, disturbed sites, roadsides, railway track sides, and wastelands [15].…”

“…Massive infestations are often observed on vacant land, disturbed sites, roadsides, railway track sides, and wastelands [15]. Parthenium weed invades and causes significant production losses in many major field crops, including wheat (Triticum aestivum L.), rice (Oryza sativa L.), sorghum [Sorghum bicolor (L.) Moench], maize (Zea mays L.), and sugarcane (Sachharum officinarum L.) in over 40 countries in Asia-Pacific and Africa [14,15,17]. The weed is also a major production constraint in grazing lands, pastures and livestock systems in many parts of the world [15,18].…”

“…Parthenium weed has been observed to benefit immensely from different climate change drivers. Parthenium weed often tolerates drought, extreme temperatures, and other abiotic stress conditions while outcompeting other plant species [14]. One major climate change driver, elevated CO 2 concentration has been noted to benefit this invasive plant the most [19][20][21][22].…”

“…One major climate change driver, elevated CO 2 concentration has been noted to benefit this invasive plant the most [19][20][21][22]. Parthenium weed, like many other C 3 plant species, improves its photosynthetic efficiency under elevated CO 2 [23,24], which is the major photosynthetic pathway throughout its life cycle except during the early rosette growth stage, when parthenium weed leaves photosynthesize through a C 3 /C 4 intermediate pathway, making it an exceptionally resilient species [14,25]. It has been observed that under elevated CO 2 , some C 3 weeds significantly increased their biomass production, resulting in enhanced crop competition and reduced crop yields [26].…”