# Maize Replacement for Controlling Invasive _Eupatorium adenophorum_
## 1 Introduction  
Agricultural lands suffer from several problems, especially the spread of weeds that affect soil productivity [1; 2]. Weeds consume the resources and diminish the growth and productivity of economic crops [3; 4]. In this regard, crops exposed to nutrient stress and drought caused low yield and quality because nutrients and water were removed by weeds [5]. To maintain soil productivity, some measures should be implemented to confront the adverse impacts of weeds [6; 7]. Frankly, herbicides as a chemical method have presented remarkable efficiency in weed control [8]. Herbicides usage achieved more than 90% efficiency in controlling various weed species while enhancing the crop productivity in weed-infested soils [9; 10]. _Eupatorium adenophorum_ (Spreng.) King & H.Rob (_E. adenophorum_) has invaded more than 30 countries, causing environmental deterioration and economic losses [11; 12]. Since 2003, it has been ranked first on the list of invasive plant species in China [13]. _E. adenophorum_ is a perennial subshrub, native to regions from Mexico to Costa Rica, and spreads rapidly and can produce biological toxins or allelechemicals. _E. adenophorum_ has purple stems and opposite diamond-shaped leaves with serrated margins. It has many types of habitats such as wetlands, gum lands, open and lightly shaded margins, plantations, shrulands, estuaries, roadsides, coastal forests and disturbed sites. It alters the soil microbial community, interferes with ecosystem structure and function, reduces the biomass of other plant species and accelerates the loss of biodiversity [14; 15; 16]. The total economic loss caused by _E. adenophorum_ to animal husbandry and grassland ecosystem services reached 3.62 billion yuan per year [17]. The total invaded area in China exceeded 30 million hectares and continues to increase [18; 19]. Technologies for the efficient and sustainable control of invasive weeds were needed. In addition, there was an urgent need to raise awareness of the risks of biological invasions. _E. adenophorum_ management includes artificial, mechanical, chemical, biological and replacement control [20; 21]. Hand uprooting is expensive, has poor efficiency and increases the risk of soil erosion. Mechanical cutting is also unsatisfactory due to the rapid asexual reproduction of new individuals from the residual roots and stems after cutting. Herbicides such as pyrazosulfuron-ethyl, thifensulfuron and picloram were effective in controlling weed growth [22]. However, chemical control was limited by the spray amounts required. Control effects are variable, and control only lasts for one year. The two measures (hand uprooting and mechanical cutting) are difficult to conduct in wetlands, open forests and steep slopes where _E. adenophorum_ is essentially uncontrollable. Traditional biological control, when available, is one of the best ways to control invasive plant species [23; 24; 25]. However, _Proccidachares utilis_, a parasitic natural enemy, exhibited negligible inhibition of the growth and reproduction of _E. adenophorum_[11]. _Dorylus orientalis_ mainly feed on the roots and stems of _E. adenophorum_, interrupting the exchange of nutrients between the roots and shoots, resulting in the death of the plant because the strong and distinctive odor of _E. adenophorum_ is the chemical signal that attracts _Dorylus orientalis_[13]. Nevertheless, _Dorylus orientalis_ could not function when its habitat was different from that of _E. adenophorum_. Replacement control technologies directed against invasive weeds are now receiving more attention [26; 27; 28]. Ecological theories and the stress-gradient hypothesis have been employed to illustrate the transformation regulations of the interacting relationships of populations [29; 30]. In a previous study, the germination and growth of _E. adenophorum_ was substantially inhibited by 90% coverage of a broad-leaved forest (_Quercus glauc_) or a mixed forest [17]. [PERSON] et al.