Potato Review

www.potatoreview.com POTATO REVIEW MAY/JUNE 2022 27 SUSTAINABLE FARMING F or more than 10 years now, Jim Reid has been involved with various trials to improve the viability and productivity of his seed potato crop. He had hosted the AHDB’s Strategic Potato Farm (sPot) over the past two years, focusing on desiccation, crop, and soil health trials. The farm itself near St Cyrus, Montrose, extends to 250 ha of mixed spring barley, malting winter wheat, winter oilseed rape and seed potatoes, which are supplied exclusively to McCain. Turning to the pest which has afflicted Scotland’s potato growers for decades, Potato Cyst Nematode (PCN), Jim explained that he has successfully been trialling a new natural biological treatment which could be game changing for the sector. “We have been GPS testing land on the farm where we know there is PCN and then have been selectively treating that area with chitinous soil amendment, which is derived from wood chip and shellfish waste,” explained Jim. “This reduces the viable PCN population within a two to three-year period.” Common practice in the UK when soil testing for PCN is for SASA to analyse 400 ml Going for green The Reids at Milton of Mathers farm have been at the heart of seed potato trials in Scotland for more than a decade, paving the way for a greener sector, less reliant on chemicals. for the first 4ha and if PCN is found, then that field parcel is taken out of seed production. An application for a soil test to lift the recording restrictions will not be accepted until a minimum of 6 years has elapsed. Statutory testing data collected by SASA shows that the area of land recorded as infested with G. pallida, currently 6,200 ha, is doubling every 7–8 years and now accounts for nearly 70% of findings. In Holland, Jim explained that soil is tested immediately after the potato crop using a grid system and sampling at 10 litres of soil per ha which increase the probability of finding very low levels of PCN to allow proactive mitigation measures. When PCN is found in pre-statutory testing, a 20m buffer strip is set aside on either side of the infected area but the rest of the field is given the greenlight for seed production. “Seven years ago, we lost 4ha of ground declared infested by PCN despite the affected area only covering the width of my truck,” he continued. “By pre-statutory GPS soil sampling and targeting applications of chitinous soil amendment, we can sustainably manage the pest and target resistant PCN varieties for seed production.” Jim has also been participating in desiccation trials and has been testing four different nozzle types for spraying, then analysing and comparing the deposition of chemicals on his plants. He has been evaluating a Guardian Air Twin nozzle, a Wilger nozzle, a Syngenta 3D ninety nozzle and a Lechler IDTA – with the latter two nozzles producing superior results. “So many farmers will choose an air induction nozzle to reduce spray drift, but they don’t optimise deposition within the canopy and most stuff we use on potatoes is ➜ Spreading chopped wheat straw before emergence of potatoes. Jim Reid of Milton of Mathers Farm.