Potato Review

38 POTATO REVIEW MARCH/APRIL 2023 CUPGRA Any approach taken must maintain or increase marketable yield with similar or reduced cultivations/inputs over a rotation, he emphasised, noting that cover crops can help in a number of ways, such as improving soil physical properties and biodiversity, but risks and bene ts should be carefully evaluated. If the decision is taken to go ahead and grow cover crops, their full impacts should be measured. For example, the cost of inputs used to grow and then destroy cover crops needs to be balanced against changes in marketable yield over a long time period (10-12 years). One of the disadvantages of growing them, within a vegetable rotation, are strong indications that autumn cover crops may provide a continual green bridge linked to encouraging wireworm neonate survival. Other anecdotal evidence suggests some plant species grown as cover crops may provide the right environment to incubate diseases such as rhizoctonia and encourage multiplication of root lesion nematodes linked to verticilliumwilt. Work is continuing in Canada looking at the long-term e ects of growing potentially wireworm antagonistic buckwheat or brown mustard as cover crops within the rotation. is may make cover crop options more attractive in blocks of land within vegetable rotations however further investigation is still required, he said. “Growers should also investigate any particular cover crop claims. For example if it is being recommended as being nematode resistant, it is important to ask which species of nematode is being referred to,” he said. “ ere are still many gaps in our understanding of the nuances of cover crops and the relationships between the di erent species grown together as cover crops.” He said a useful resource to investigate some of the interactions between pests and diseases with regard to cover crop and cash crops is the Best4soils.eu database “Sustainability is often mentioned in relation to cover crops and this can be interpreted in many ways. However a clearer target for one aspect of sustainability would be assessing and measuring how cover crops within a rotation could help reduce the overall greenhouse gas (GHG) emissions per tonne of production of a particular rotation.” If the overall target is reduced GHG emissions/carbon footprint, knowing your soil properties can be key to achieving what you are looking for, he said. For example, carbon which has been locked up in the soil from cover crop growth ideally should stay locked up, however this is di cult to achieve on sands within vegetable rotations. erefore other complementary measures may need to be considered such as better utilisation of new varieties with higher yields or lower input requirements, reducing the GHG emissions per tonne produced. In addition, fossil fuel free ammonium nitrate fertilisers, produced with renewable energy and hydrogen from electrolysis, which have an 80-90% reduction in carbon emission during production could result in a signi cant reduction in the GHG emission of the average potato crop of in the order of 20%. “ ese options could providemore reliable reductions. However, the end-customers will need to be prepared to pay for any cost increases.” Collaboration key to achievement A collaborative approach is key to creating opportunities to satisfy the consumer, said Bernard de Geus of Holland Innovative Potato, a Dutch organisation of potato companies established in 2017 to facilitate and coordinate joint pre-competitive research activities. Current members include potato breeders, processors and two sector associations and the aims of the organisation is to seek practical solutions for products and processes to help the potato supply chain to meet consumer demand. Opportunities could include new business and transaction models, in uencing regulation and legislation, and globalisation. Although there are challenges in trying to bring people together, it makes sense because the costs of external research are not cheap as it is means for building the capacity for research to take place, he told delegates. “One of the di culties is that the goals of our sector are often common in the early stages but they do not deliver in the long term,” he said. e organisation was formed in a number of phases; with the de ning moment being a visit by the Minister of Agriculture to Solynta in 2014. It then spent three years building a consortium and securing funding, and then founding the association in 2017. “Our rst aims were to improve yield, quality and stability of potato production, by enhancing the understanding of agronomy and genetics. is was through the development of practical guidelines for monitoring and controlling cultivations, and we also looked at new breeding traits.” Working with the University of Wageningen, the organisation identi ed research leads. “ is was not easy because the di erent sub-sectors have di erent views on what is needed in both the short and long term, so we had to manage expectations. We knew many of the members wanted to turn knowledge into a product very quickly.” is led to the challenge of keeping people ‘on-board’, and Bernardo emphasised the need to listen and address the needs of the partners in industry and academia through careful management. He re ected that the EU ‘Green Deal’ is imposing challenges on the potato value chain, and there is a need to address the speci c needs connected to the regulatory environment. CUPGRA attendees heard that more needs to be done to educate the public. Sebastian Eves-van den Akker. Prof Ian Toth of the James Hutton Institute.