10 February 2023
Crop health advisors at FERA look at the outlook for this spring.
HOT dry weather and input cost inflation dominated the 2022 potato season. While crops which had access to water thrived, others senesced early, resulting in lower yields.
At the same time, the marketable yield from some fields has been reduced by quality issues such as secondary growth, cracking and greening. Elsewhere, crops which have remained green later into the season are likely to have high dry matter, making them prone to bruising – and some growers have chosen to burn crops off early at the expense of reduced yields.
These factors have helped to ensure a long harvest window. Struggling maincrops were harvested in many areas well before the end of August, while others were still green and continuing to grow. As harvest ramps up through September and October, grower’s thoughts turn to next season.
Quality issues, high production and energy costs, and subdued prices are making many consider their production plans.
High energy prices mean high storage costs, and while ware growers are becoming more adept at managing sprouting without the use of CIPC, the dry weather has raised questions about the effectiveness of maleic hydrazide treatments which will only be answered later in the season. Because of these challenges, and the ongoing situation around seed imports from Europe, a number of growers may be actively considering holding on to some of their smaller non-MH treated crops for use as home-saved seed.
While industry experts accept that this may be a useful approach for many, they stress that growers need to consider the risks carefully and be aware of the potential for virus and other issues in home-saved seed.
“We have seen very high aphid numbers – more than seven-times the average in some parts of the country – and in those areas we are anticipating very high levels of virus infection, particularly PVA and PVY,” says Fera entomologist Larissa Collins.
“Numbers of Myzus persicae (peach potato aphid) have been seen at four-times the usual levels, and there have also been very high numbers of Aphis fabae (black bean aphid). With such high aphid populations, there is a very high probability of virus transmission and crops from the affected areas will be particularly risky to use as seed.”
In July, Defra’s Animal & Plant Health Agency (APHA) also warned that the hot dry weather could not only reduce yields, but also lead to late virus infections in crops, and advised growers to ‘take steps to make sure they are confident stocks will meet marketing standards.’
Despite the ongoing restrictions on seed potato imports from the European Union, seed potato
companies believe that many English growers will find it easier to obtain the seed they require under Defra’s revised rules, although with high costs and potentially lower yields, some
growers may be looking to reduce production costs through the use of home-saved seed. Anything which may be destined for seed use should be risk assessed and tested.
“It may be that early-season infection has been the biggest risk this year, but whenever peak
transmission actually occurred, due to the high risk of PVA and PVY infection this season it is vital that growers test potential planting material,” stresses Fera virologist Adrian Fox.
The relatively small cost of postharvest tuber virus testing massively outweighs the risk of having an infected crop next year, and those benefits are magnified when the risks of cross contamination between infect home-saved crops and clean certified crops are considered.”
Growers who have been using Fera’s aphid monitoring service this year will already have a good idea of the virus risk to their crops. For complete peace of mind, Fera’s tuber testing services can confirm the presence of virus in crops, enabling growers to make informed decisions about crop marketing or keeping home-saved seed.
Source: Fera Science