CSIRO Ecosystem Sciences and Sustainable Agriculture Flagship, Canberra, Australia.
Department of Agriculture and Food, Irrigated Agriculture and Diversification, Perth, Australia ; The University of Western Australia, School of Animal Biology, Perth, Australia.
PLoS One. 2014 Feb 19;9(2):e89119. doi: 10.1371/journal.pone.0089119. eCollection 2014.
Prophylactic use of broad-spectrum insecticides is a common feature of broad-acre grains production systems around the world. Efforts to reduce pesticide use in these systems have the potential to deliver environmental benefits to large areas of agricultural land. However, research and extension initiatives aimed at decoupling pest management decisions from the simple act of applying a cheap insecticide have languished. This places farmers in a vulnerable position of high reliance on a few products that may lose their efficacy due to pests developing resistance, or be lost from use due to regulatory changes. The first step towards developing Integrated Pest Management (IPM) strategies involves an increased efficiency of pesticide inputs. Especially challenging is an understanding of when and where an insecticide application can be withheld without risking yield loss. Here, we quantify the effect of different pest management strategies on the abundance of pest and beneficial arthropods, crop damage and yield, across five sites that span the diversity of contexts in which grains crops are grown in southern Australia. Our results show that while greater insecticide use did reduce the abundance of many pests, this was not coupled with higher yields. Feeding damage by arthropod pests was seen in plots with lower insecticide use but this did not translate into yield losses. For canola, we found that plots that used insecticide seed treatments were most likely to deliver a yield benefit; however other insecticides appear to be unnecessary and economically costly. When considering wheat, none of the insecticide inputs provided an economically justifiable yield gain. These results indicate that there are opportunities for Australian grain growers to reduce insecticide inputs without risking yield loss in some seasons. We see this as the critical first step towards developing IPM practices that will be widely adopted across intensive production systems.
预防性使用广谱杀虫剂是世界各地大田谷物生产系统的共同特征。减少这些系统中农药使用的努力有可能为大面积农业土地带来环境效益。然而，旨在使害虫管理决策与简单施用廉价杀虫剂脱钩的研究和推广计划收效甚微。这使农民处于高度依赖少数几种产品的脆弱地位，这些产品可能因害虫产生抗药性而失去效力，也可能因监管变化而不再使用。制定综合虫害管理 (IPM) 策略的第一步是提高农药投入的效率。特别是要了解何时何地可以不使用杀虫剂而不会有产量损失的风险。在这里，我们量化了不同害虫管理策略对害虫和有益节肢动物丰度、作物损害和产量的影响，跨越了澳大利亚南部五个种植谷物的多样性环境的地点。我们的研究结果表明，虽然更多地使用杀虫剂确实减少了许多害虫的数量，但这并没有带来更高的产量。在使用杀虫剂较少的地块中可以看到节肢动物害虫的取食损害，但这并没有转化为产量损失。对于油菜籽，我们发现使用杀虫剂种子处理的地块最有可能获得产量收益；然而，其他杀虫剂似乎是不必要的，而且经济成本高昂。考虑到小麦，杀虫剂的投入都没有带来经济上合理的产量增益。这些结果表明，澳大利亚谷物种植者有机会在某些季节减少杀虫剂的投入而不冒产量损失的风险。我们认为这是朝着广泛采用集约化生产系统中的 IPM 实践迈出的关键第一步。
