The warning was issued by East Malling Research (EMR) storage specialist David Johnson, who said that most growers are clued up enough to take the right preventative action.
According to the EMR LTB predictive computer model the LTB risk is severe. In addition, fruit analysis indicated that bitter pit was likely to be pretty high. The LTB model is based on summer weather conditions and factors like low phosphorus concentration (below 9mg per 100g fresh weight) and late picking that can also make the fruit more prone to the problem.
Although increasing the store temperature by 0.5 degsC to 4.5 degsC or 5 degsC helps reduce the LTB risk, it's essential for growers to carry out regular fruit monitoring throughout the fruit's storage life to assess its internal condition, advised Johnson. "You can see the first signs of LTB as very faint browning at the calyx end," he explained. "Shelf life tests are also essential.
"This means keeping the fruit for seven days at room temperature (about 20 degsC), although some growers do a 14-day test as well."
If LTB or bitter pit develops during these tests it is necessary to market the fruit earlier than otherwise to avoid losses and ensure the fruit is acceptable to supermarkets.
"Once bitter pit reaches a level that supermarkets won't accept - say, five per cent - you really should act," Johnson said.