Newer apple varieties present different challenges when seeking to avoid rot in storage, East Malling Research (EMR) plant pathologist Dr Robert Saville told a fruit storage conference at the Kent research station last week.
"The fungus Nectria is a problem in newer varieties and is becoming more widespread as they are more widely planted," he said. But newer varieties can also tolerate lower storage temperatures, which may account for the lower overall mean losses to rots, Saville suggested.
He described Jazz, which in EMR's figures shows the lowest proportion of losses, as "a much tougher apple, so you don't see much brown rot (Monilinia fructicola), which otherwise is our biggest rot".
EMR data also show a rising incidence of Gloeosporium, which causes target-like rots on skin. "It is the most important rot in the rest of Europe," said Saville. "Rots here are not too bad at the moment, but there is still much to learn about it."
Last year's apple crop has also suffered more from Phytophthora syringae, "which is synonymous with wet weather", particularly in later-harvested fruit, added Saville.
EMR has accumulated decades-worth of data on the impact of each rot on the UK crop and continues to survey packhouses. "It's important to identify what rot it is so you know what to treat it with," said Saville. "We at EMR also want to know where to target our research."
Cherry breeding Research programme
A ten-year cherry-breeding programme at East Malling Research aims to yield more commercially appealing varieties, junior research leader Dr Emma Skipper told the fruit storage conference.
It will assess a large F1 population genetically, seeking individuals with desirable flavour, texture and shelf life characteristics.
"Cherries lose flavour in storage and can be damaged through the supply chain," Skipper explained. "Good flavour is also essential for repeat purchases."