Potato Review

www.potatoreview.com POTATO REVIEW JULY/AUGUST 2020 21 OVERSEAS FOCUS 2% extraction of total annual discharge of the River Columbia in order to preserve ecosystems such as vital salmon runs further downstream and killer whale numbers at the estuary where it meets the ocean. Appetite for expansion e appetite for continued expansion and development is clear. While the average potato area per grower in WA is 275ha, some of the larger growers in the basin are responsible for in excess of 3000ha each. Despite the appearance of huge investment, huge return, WA growers on average experience pro ts of £356/ha, highlighting the drive for large scale. e high capital outlay required has seen ventures backed by external investors, some with nancial interests in agriculture across the globe, giving rise to super farms who farm tens of thousands of hectares and hundreds of pivot irrigators in the basin. is size presents huge economies of scale and a requirement for mechanisation of an incomparable level to the UK. Planting rates of 150-200ha per day in April are not uncommon and harvesting 10,000t/day can see multi-gang harvest campaigns lasting only four weeks in late September and early October. ese narrow cultivation windows are necessitated by harsh winters which can see temperatures drop to -7 o C in autumn. Accepted tolerance to chemical use Aerial spraying is still very much practised, with land under centre pivot irrigation often never having another wheel-based eld activity performed between planting and harvest. Weekly petiole testing can be implemented through on-farm laboratories, with nutrient inputs added and adjusted in as little as 24 hours from the sample being taken, this information being fed into the pivot systems fertigation system to ensure that the potato plants are always fully supplied with part of the 450kg/ha they receive over the season. e pivots themselves can also be used to apply programmes of blight, herbicide, and importantly the application of liquid nematicide fumigation pre planting for Root Knot Nematode (RKN), something that is now prohibited in the UK. e di erence in the chemical arsenal on o er doesn’t stop there, as advantages in sprout suppression in the form of CIPC and DMN are relatively low cost options available to growers, as oppose to the expensive and relatively untested options now reality in the UK. is accepted tolerance to chemical use in the US has allowed WA ➜ “Should the chemistry available to WA growers reduce, the area would be faced with the very real prospect of productivity falling and potato rotations based on one in three becoming unviable.” The USA retail o ering sees potatoes sold by colour rather than variety.