Ecologically engineering a sustainable sugar beet landscape matrix informed by molecular tools, satellite imagery and bioeconomics.

甜菜是一种满足国内一半糖需求的作物，种植在英国1000平方公里的耕地上，主要是在东英吉利亚。然而，这种作物受到三种病毒的威胁，统称为病毒黄化，通过损害植物的光合作用能力而大大降低产量。这些病毒是由蚜虫传播的，在2018年之前的30年里，甜菜种子被一种类烟碱种子处理剂包衣，这种种子处理剂可以有效和系统地控制蚜虫的进食，从而控制病毒黄化的传播。然而，广泛引用的类烟碱治疗具有有害的非目标影响，最明显的是改变了授粉者，特别是蜜蜂的行为。因此，欧盟于2018年4月27日禁止使用烟碱类种子处理剂。禁令实施后，温暖的天气、甜菜提早出苗和大量蚜虫的共同作用，导致2020年作物受到病毒黄化的严重影响，种植者平均产量损失38%，价值4300万英镑，在剑桥郡部分地区损失高达100%。作为回应，负责确保甜菜种植者茁壮成长的征税委员会BBRO向Defra申请，如果我们的“Rothamsted模型”预测收获时病毒黄化将导致甜菜作物产量损失超过9%（2021年）和19%（2022年），则在2021年和2022年对甜菜使用类烟碱种子处理。于二零二一年，该等条件未能符合，但于二零二二年，Defra批准豁免使用类烟碱Cruiser SB种子处理。然而，类烟碱种子处理在未来并不是一种可持续的做法，特别是考虑到雄心勃勃的环境土地管理计划下的新农业政策，特别是可持续农业激励计划（SFI）。展望未来，允许使用类尼古丁可以基于区域风险，限制环境影响。或者，种植者和行业可以集体决定完全放弃类尼古丁，或者由政策制定者授权这样做。为了在这两种情况下生产可持续和经济上可行的糖料作物，我们需要知道病毒传播途径的行为和规模，然后预测其在收获时的影响。使用分子工具和高光谱无人机来检测叶片黄化，我们将随着时间的推移跟踪受疾病感染的甜菜的发展，并检查作物中病毒黄化的存在，确定田间边缘的关键非作物病毒水库，并跟踪局部传播到邻近作物。这对于下一代病毒黄化模型的进展至关重要，这是一个未来的目标，将为蚜虫管理提供强大的决策支持工具。为了进一步推进这一建模目标，我们需要了解景观尺度上的病毒风险，并计划使用卫星图像来量化田间边缘栖息地的范围，这是病毒黄化的潜在来源，以及冬季支持蚜虫的其他作物。目前还没有统计数据表明，在甜菜附近种植油菜会增加病毒载体的威胁，但许多种植者接受了这一观点。利用Rothamsted掌握的2020年甜菜病媒和病毒发病率的广泛数据，我们将使用2020年的卫星图像来获得邻近度，以估计附近油菜作物网络构成的威胁。一个生物经济模型，结合农业经济学和甜菜系统的生物学，将用于探索病毒爆发的风险如何影响不同支付选项和不同景观情景下的盈利能力。迫切需要了解这一点，以实现粮食安全和可持续性目标。这项提案将提供所需的科学进展，以适应所有人的甜菜种植未来。

Sugar beet, a crop which meets half of domestic sugar demand, is grown on a thousand square kilometres of arable land in the UK, mostly in East Anglia. However, the crop is threatened by a complex of three viruses, known collectively as virus yellows, that dramatically reduces yield by compromising the plant's ability to photosynthesize. The viruses are transmitted by aphids and, for 30 years up until 2018, sugar beet seed was coated with a neonicotinoid seed treatment that effectively and systemically controlled aphid feeding and thus the transmission of virus yellows. However, neonicotinoid treatments were widely cited has having detrimental non-target impacts, most notably changing the behaviour of pollinators, particularly bees. As a result, the EU banned the use of neonicotinoid seed treatments on 27th April 2018. Following the ban, a confluence of warm weather, early sugar beet emergence and abundant aphids saw the 2020 crop severely affected by virus yellows and growers experienced average yield losses of 38%, which were valued at £43 million and rose to 100% losses in parts of Cambridgeshire. In response, the BBRO, the levy board charged with ensuring that growers of sugar beet thrive, applied to Defra for a derogation to use neonicotinoid seed treatments in sugar beet in both 2021 and 2022 if our 'Rothamsted Model' predicted that more than 9% (2021) and 19% (2022) of the sugar beet crop yield would be lost to virus yellows at harvest. In 2021 these conditions were not met, but in 2022, a derogation was granted by Defra to use the neonicotinoid Cruiser SB seed treatment. However, neonicotinoid seed treatments are not a sustainable practice for the future, especially considering new agricultural policy under the ambitious environmental land management schemes, particularly the Sustainable Farming Incentive (SFI). Projecting forward, the permission to use of neonicotinoids could be based on regional risks, limiting the environmental impact. Alternatively, growers and the industry could decide collectively to move away from neonicotinoids altogether or be mandated to do this by policy makers. To produce a sustainable and economically viable sugar crop under either of these scenarios, we would need to know how the virus transmission pathway behaves and scales to then make predictions about its impact at harvest. Using molecular tools and a hyperspectral drone to detect leaf yellowing, we will track the development of disease-infected sugar beet over time and, examine the presence of virus yellows in the crop, identifying key non-crop virus reservoirs in field margins and tracking local spread into the adjacent crop. This is essential to progress to the next generation of virus yellows models, a future ambition that will provide a robust decision support tool for aphid management. To further progress this modelling ambition, we need to understand virus risks at the landscape scale and plan to use satellite imagery to quantify the extent of field margin habitats, a potential source of virus yellows, and other crops that support aphids during winter. It has not yet been shown statistically that oilseed rape planted nearby to sugar beet increases the threat of the virus vector, but many growers adopt to this view. Using extensive 2020 sugar beet vector and virus incidence data held by Rothamsted, we will use satellite images from 2020 to derive proximity measures to estimate the threat posed by the network of nearby oilseed rape crops. A bioeconomic model that incorporates farm economics and the biology of the sugar beet system, will be used to explore how the risk of virus outbreak affects profitability within the context of different payment options and under different landscape scenarios. There is imperative to understand this urgently to meet both food security and sustainability goals. This proposal will deliver the science needed to progress to a farming future for sugar beet that will suit all.