1 Management of Crops to Prevent Pest Outbreaks Claudia Daniel,* Guendalina Barloggio, Sibylle Stoeckli, Henryk Luka and Urs Niggli Research Institute of Organic Agriculture, Forschungsinstitut für biologischen Landbau (FiBL), Frick, Switzerland Introduction pests on oilseed rape are usually higher than on vegetables. Therefore, less control is used Organic farmers face the same potentially in oilseed rape which might lead to the severe pest problems as their colleagues in build-up of large pest populations, threatening integrated pest management (IPM) and conven- nearby vegetable fields. With the increasing tional farming systems. However, approaches area of oilseed rape production, pest prob- to manage the pest insects are different because lems in these crops are likely to increase. the aim of organic farming is a holistic system perspective rather than simple reductionist Standards for Organic and IPM control approaches. Organic cropping sys- Production: Similarities tems are designed to prevent damaging levels of pests, thus minimizing the need for direct and Differences and curative pest control (Peacock and Nor- ton, 1990). Within this chapter, we will briefly Organic farming explain the standards for organic farming, which also set the framework for pest control. Organic farming is regulated by international We present a conceptual model for pest control and national organic production standards, in organic farming and describe the influence such as the IFOAM (International Federation of of functional agrobiodiversity and conservation Organic Agriculture Movements) Norms (IF- biological control on pest management. We OAM, 2012), Codex Alimentarius (FAO and focus on the use of preventive strategies and WHO, 2007), or European Union (EU) regula- cultural control methods. The system approach tion (EC, 2007). Organic standards all have is illustrated with examples in organic Bras- the same principal norms for plant produc- sica vegetable and oilseed rape production, tion as described in the Codex Alimentarius: because these economically important crops Organic agriculture is a holistic production (Ahuja et al., 2010) are attacked by a broad management system which promotes and range of different pest insects (Smukler et al., enhances agroecosystem health, including 2008; Ahuja et al., 2010) and show different biodiversity, biological cycles, and soil levels of tolerance. Economic thresholds for biological activity. It emphasizes the use of * Corresponding author: [email protected] © CAB International 2018. Handbook of Pest Management in Organic Farming (eds V. Vacante and S. Kreiter) 1 2 C. Daniel et al. management practices in preference to the strategies are centrepieces of IPM strategies. use of off-farm inputs, taking into account Nevertheless, pest management in IPM is still that regional conditions require locally dominated by the use of synthetic pesticides. adapted systems. This is accomplished by In particular the strong focus on economic using, where possible, cultural, biological, thresholds leads to a reductionist view of the biotechnical, physical and mechanical systems (El-Wakeil, 2010). Environmental methods, as opposed to using synthetic materials, to fulfil any specific function considerations and the presence or absence within the system. of beneficial insects are mostly not included (FAO and WHO, 2007) in the economic thresholds (El-Wakeil, 2010). According to Ehler (2006), this perpetuates a Thus, the maintenance of plant health pri- ‘quick-fix mentality’, where symptoms are marily relies on preventative measures, treated instead of causes. IPM principles are such as: (i) the choice of appropriate species only reluctantly implemented by the farmers and varieties resistant to pests and diseases; due to higher costs, and higher risk of failures (ii) appropriate crop rotations, cultivation of non-chemical control methods, as well as techniques, mechanical and physical methods; lack of experience with these methods (Gruys, and (iii) the protection of natural enemies of 1982). Incentives for farmers to use alterna- pests. In the case of an established threat to tive methods are missing, because the ad- a crop, plant protection products may only vantage of using sustainable and preventive be used if they have been authorized for use measures ‘is at the social and environmen- in organic production. Within the EU, prod- tal level and on the long-term, rather than at ucts authorized for organic farming are the private economic level and on the short- listed in Annex II of the implementation term’ (Gruys, 1982). In addition, the low rule 889/2008 (EC, 2008). Substances used price for synthetic pesticides does not re- for plant protection should be of plant, ani- flect the true ecological costs. Thus, for the mal, microbial or mineral origin. Genetically individual farmer it is often more econom- modified organisms (GMOs) and products ical to use a curative pesticide instead of produced from or by GMOs, as well as min- preventive measures. The use of pesticides eral nitrogen fertilizers are not allowed. is more regulated in organic farming sys- Chemically synthesized products are only tems: only naturally derived substances are allowed if they are not available in sufficient allowed. As availability and efficacy of quantities in their natural form (e.g. phero- these substances is limited and most of mones) and if conditions for their use do them are considerably more expensive than not result in contact of the product with the synthetic pesticides, organic farmers have a edible parts of the crop (e.g. application in stronger incentive to consequently apply dispensers). preventive measures. IPM Conceptual Model for Pest IPM standards were developed and defined Management in Organic Farming by the International Organisation for Bio- logical and Integrated Control (IOBC) (Boller A conceptual model for pest management in et al., 2004). With the Sustainable Use Dir- organic farming (Fig. 1.1) was proposed by ective (EC, 2009), IPM has become the main Wyss et al. (2005), refined by Zehnderet al . part of the European crop protection policy. (2007) and complemented by Luka (2012, Central goals of IPM are the prevention and cited in Forster et al., 2013). The fundamen- suppression of harmful organisms, as well as tal first step of this holistic approach is the the preference of non-chemical methods with benefits of nature conservation measures: eco- few side effects on non-targets (Kogan, 1998). system diversity is increased through habitat In addition, monitoring of pest insects, eco- management, extensification of land uses, es- nomic action thresholds and anti-resistance tablishment of non-crop habitats and biotope Management of Crops to Prevent Pest Outbreaks 3 e Direct control: approved insecticides of biological or mineral origin, pheromones, physical measures Inundative or inoculative biocontrol: release of living, beneficial micro- and macroorganisms ect and curativ (viruses, bacteria, fungi, nematodes, arthropods) pest management Dir Habitat management at field level: push–pull strategies, trap e crops and conservation biological control (wildflower strips and companion plants to enhance beneficial antagonists) entiv ev Cultural and management practices: crop rotation, resistant cultivars, farm-site selection, timing of planting/harvesting, improving soil fertility ect and pr Nature conservation measures (increase ecosystem diversity through habitat pest management management): extensification of land uses, enriching biodiversity of non-crop Indir habitats, biotope networks, interlinking of crop and non-crop habitats Fig. 1.1. Conceptual model for pest management in organic farming. (Adapted and supplemented based on Luka, 2012, cited in: Wyss et al., 2005; Zehnder et al., 2007; Forster et al., 2013.) networks. The second step of the pyramidal discussed in detail in Chapters 2 and 3 of model are cultural practices applied by the this volume, respectively. farmers in order to avoid pest damage (Pea- cock and Norton, 1990). These practices include crop rotation, increasing crop diversity, timely planting and harvesting, transplant- Nature Conservation Measures: the Basis ing, weed management, choice of resistant for Biodiversity and Ecosystem Services varieties and avoiding areas with high pest presence on the farm level. These practices According to the Convention on Biological go hand in hand with the third step which Diversity of Rio de Janeiro in 1992, biodiver- is habitat management at the field level sity encompasses the variety of life on earth (i.e. companion plants, tailored wildflower ranging from genes, through species, to entire strips, push–pull strategies) which aims at ecosystems (United Nations, 1992). Ecosys- interlinking crop and non-crop habitats. tem diversity covers the diversity of habitats These first three steps create a broad and or patches within a landscape and includes solid basis for healthy plant development. the diversity of farming systems, ratio of ar- Direct control methods based on biocontrol able land to other land uses as well as inter- organisms or bioinsecticides are the fourth actions between agricultural land and nearby and fifth steps of the model. However, these natural biotopes. Ecosystem diversity and di- methods can have side effects on beneficial versified cropping systems have a range of arthropods and thus adversely affect eco- benefits, both short term (e.g. by increase in system services needed for pest prevention. crop yield and quality due to improved