Farming Monthly National September 2018 | Page 21

| Root Crops Potato storage preparation tips Given the dry summer many have experienced, growers may be tempted to leave crops to grow out to maximise yield this season. owever, we would advise to balance this with the need to get crops of the right quality into store in best condition, especially if long-term contracts need to be met. Achieving adequate skin set is a crucial element of storage preparation. This may be difficult in some varieties but remains important if disease is to be kept at bay and weight loss minimised. Use an effective desiccation strategy to prepare the crop for storage and plan its use around an efficient store loading plan to minimise down time and periods where stores are left waiting for loading to be completed. Recent rain will hopefully have eased the risk of bruising, but the hot growing conditions have tended to encourage early dormancy break and sprout growth in short-dormant varieties; these will need cooling quickly or treating with CIPC early to maximise control. The accumulated heat of the summer means that some crops H www.farmingmonthly.co.uk have physiologically aged more than usual this summer. This has shown with both early sprout growth in the ridge (right) and dormancy break immediately after lifting (in early crops). It is logical therefore to expect an increased risk of senescent sweetening problems later in store. With this in mind, it is worth taking steps to conserve physiological age (i.e. exposure to degreedays) wherever possible during storage. For example, this might be achieved by using a quicker pull- down than usual or by storing at a lower temperature. The key is to monitor crops closely to ensure that there is regular assessment of quality in relation to market needs. Some crops that have extensive sprout growth in the field will also need to be watched closely as stores are loaded. Many sprouts will break off during the harvesting process but this potentially provides a point for disease ingress. There are several reports of pink rot (below left) in the field and the risk from fungal infection will be high even if temperatures Pink rot (left) and late blight (right) infection in tubers adjust to more seasonal levels, close to 15°C. Late blight (below right, with characteristic rust coloured lesions) also remains a threat in places especially in those crops which may have been infected early in the season. Disease risk from pink rot could be greatest in crops grown in fields which were waterlogged last year. If either disease is encountered, reduce temperature as quickly as possible and maintain ventilation until the crop can be assessed fully and, if necessary, moved. See https://potatoes.ahdb.org.uk/ gallery/potato-diseases for further guidance. Speaking at a recent AHDB Stategic Potato Farm Field Walk at Somerby Top, near Brigg, Adrian Cunnington from SBCSR reminded delegates to minimise risk by ventilating crops when they first come in store to remove field heat and aerate the stack to aid curing. He said: “Don’t overfill boxes as this constrains airflow at the most critical time for the crop. If tuber size is below average it also provides additional resistance to air penetration through the potatoes.” Mr Cunnington went on to remind growers of the need to minimise temperature differences in storage to manage the risk of condensation. “This can be especially important when field conditions are warm at harvest and a lot of field heat is having to be removed quickly. Humidity can rise quickly as the crop is cooled and it then only needs a small temperature difference to result in free moisture being deposited within the crop” he warned. You can help by alerting us to cases of sprouting-in-the-ridge, performance of desiccants, rates of skin set etc. by calling the Storage Advice Line. While we can’t respond to all short messages on the day they arrive, you'll get free initial advice, and keeping us posted will allow us to point the team at specific issues as and when they arise” Storage advice is available from the SBCSR team on 0800 02 82 111 September 2018 | Farming Monthly | 21