Herbicide resistance modelling: past, present and future

Abstract

Computer simulation modelling is an essential aid in building an integrated understanding of how different factors interact to affect the evolutionary and population dynamics of herbicide resistance, and thus in helping to predict and manage how agricultural systems will be affected. In this review, we first discuss why computer simulation modelling is such an important tool and framework for dealing with herbicide resistance. We then explain what questions related to herbicide resistance have been addressed to date using simulation modelling, and discuss the modelling approaches that have been used, focusing first on the earlier, more general approaches, and then on some newer, more innovative approaches. We then consider how these approaches could be further developed in the future, by drawing on modelling techniques that are already employed in other areas, such as individual-based and spatially explicit modelling approaches, as well as the possibility of better representing genetics, competition and economics, and finally the questions and issues of importance to herbicide resistance research and management that could be addressed using these new approaches are discussed. We conclude that it is necessary to proceed with caution when increasing the complexity of models by adding new details, but, with appropriate care, more detailed models will make it possible to integrate more current knowledge in order better to understand, predict and ultimately manage the evolution of herbicide resistance.

Occasional mouldboard ploughing slows evolution of resistance and reduces long-term weed populations in no-till systems

“…An empirical study of this issue would be a major undertaking, requiring many years and also large areas of land to adequately study the evolutionary dynamics of large populations and initially rare resistance alleles, and so a modelling approach is appropriate and necessary (Neve, 2008;Neve et al, 2009;Renton, 2012;Neve et al, 2014;Renton et al, 2014). In this study we used the Polygenic Evolution of Resistance To Herbicides (PERTH) model to predict whether systems incorporating MB tillage would have a lower risk of weeds developing resistance to a soil-residual herbicide applied atsowing compared to NT systems.…”

The legal changes regarding chemical protection used by amateurs, available active substances and the expected impact on the development of pest resistance in Poland

“…Resistance of harmful organisms for chemical plant protection products is a growing problem in agriculture (Clarke at al., 1997, Metcalf, 1989, Zamojska and Malinowski, 2012, Renton at al., 2014. International orgnisations, such as European and Medditeranean Plant Protection Organisation recognize this problem and carry out multiple activities on resistance to plant protection products (EPPO 2014).…”

Optimizing pesticide spray coverage using a novel web and smartphone tool, SnapCard

“…Thus, applications of pesticides should be considered a selection pressure imposed by humans, and the sustainability of a particular pesticide becomes a matter of resistance management: how to kill enough pests to avoid economic losses but at the same time not impose a strong and persistent selection pressure leading to resistance in the target pest population and shortening the useful life of the pesticide. Many factors influence the actual level of pesticide resistance development in a pest population, including the following (Nansen and Ridsdill-Smith 2013;Gassmann et al 2009;Georghiou and Taylor 1976;Renton et al 2011Renton et al , 2014: (1) genetic factors (i.e. frequency, dominance, and expressivity of resistant alleles and their interactions with other alleles, fitness costs associated with resistance, past selection pressures in pest population, and whether the resistance is monogenic or polygenic), and (2) biological factors (fecundity, generation and development times, mating behavior, level of polyphagy, migration/dispersal and mobility, fitness costs of resistance development, and feeding biology).…”

“…As discussed by recent authors (Whalon et al 2008;Nansen and Ridsdill-Smith 2013;Renton et al 2014) and publicly available databases (the Arthropod Pesticide Resistance Database (APRD, http://www.pesticideresistance.org/), a main characteristic of most known pests is their ability to develop resistance to pesticides. With the continuously growing list of pesticides becoming ineffective due to resistance, insecticides being phased out due to concerns about their adverse environmental effects, and with chemical companies having to spend increasing amounts of resources on getting new active ingredients registered for commercial use, it seems reasonable to reflect on the longterm sustainability of the current pesticide application practices.…”

“…Likely consequences of low spray coverage and target pests developing behavioral avoidance/resistance include reduced pest suppression and therefore an increase in number of applications (because after a spray failure, farmers have to come back and spray again), increased risk of environmental contaminations, and potential loss of agricultural productivity. There are also quantitative analyses highlighting that low dosage of herbicide applications (which is an indirect effect of low spray coverage) may lead to increased risk of weed species developing resistance (Renton et al 2011(Renton et al , 2014Powles and Yu 2010;Mortensen et al 2012).…”