No. 5/23 SUBSCRIBER EDITION: please go to potatostorageinsight.com/subscribe to sign up
This is your May edition of Synopsis, Potato Storage Insight's monthly bulletin with news, technical content and new developments on all things potato storage.
In this month's Technical Insight, we are looking at the technical importance of carbon dioxide, a major product of respiration, in determining potato quality from storage.
Fortunately, despite some incessant rain in some parts of the country, a majority of growers have reached, or are now moving towards, the finishing line for this season's planting activity. With a cold spring and wet weather resulting in a delayed start to growth, there have been reports of very slow emergence and problems like chain tuberisation and/or little potato disorder in fields early on...
Meanwhile in storage, there is continued movement of crop to market as supplies tighten, Returns for late deliveries have risen as price pressure comes from the market due to the likely delayed availability of new crop.
It is notable that late season sprout suppressant applications are moving from DMN (which has a 30 day harvest interval) to less restricted options like mint and orange oil, so there is more flexibility for marketing.
PSI is available to provide guidance and advice on all aspects of potato storage; if you think we can help you, call Adrian on 07970 072260 or email adrian@potatostorageinsight.com.
BEST PRACTICE for May/June
Store cleaning options
Disease carry-over is always a concern when it comes to end of season so it is important to plan ahead to ensure your store is ready to receive the best possible treatment as soon as it is emptied and there's a chance to get the building ready for next season.
A key opportunity for 'cleaning' can be taken if you have the benefit of a large area of concrete for holding boxes on. If boxes can be stacked for a few weeks outside in the summer months, the UV part of the light spectrum can set to work on killing any pathogens living on the timber.
There is no specific need to wash boxes for most crops (perhaps with the exception of high-grade seed), but removal of crop debris is an obvious measure that will reduce disease risk. Stepping up to specific steam-cleaning of boxes (with a disinfectant) is only really necessary where boxes have been contaminated by the exudate from breakdown of the previous crop.
Once boxes are dealt with, and dust containing disease spores have been vacuumed out of the store (DO NOT SWEEP - this just relocates the problem), then there is always the opportunity to have the store treated with a disinfectant like peracetic acid (PAA, eg Jet 5) which can be applied as a thermal fog. Contractors are available to do this job but do only consider treating stores that have been thoroughly cleaned beforehand as the PAA is neutralised by organic matter.
Good news from JHI. Alison Lees, David Cooke and their team have managed to secure sufficient funding to continue their Fight Against Blight service for the 2023 growing season. Intelligence from the South of England indicates that the disease is already escalating given the continued wet weather as temperatures slowly begin to rise, so it is important to check dumps and other potential carry-over locations to control spread. Please report outbreaks through the FAB website at https://blight.hutton.ac.uk/
TECHNICAL INSIGHT
Carbon dioxide
Carbon dioxide is produced as part of the potato respiration process that takes place wherever we store the crop. Because we are holding a living organism, the potato - like you and me - is converting oxygen and sugar into energy to keep the tuber alive and by-products of which carbon dioxide is the primary one.