Afflicted Apples, Reduced Rotations and Towering Tomatoes
Your questions answered
Are my afflicted apples alright?
We had an abundant harvest from one of our apple trees. The majority of the fruit was great quality, had near perfect skin and was perfect in taste – not too sweet, not too sour. However, some of the apples had a marbling pattern inside.
We ate them anyway and the marbling didn’t affect the taste at all. This is our second year harvesting apples from this tree but this is the first year with the marbling. Any ideas what this could be and what I may have done wrong?
Michelle S., Trentham, Vic
The problem is called water core and is a result of an excess of a sugar alcohol called sorbitol in the fruit. I’ve had this occur in my fruit in the past.
There’s no clear cause of water core and the advice for preventing it is loose, but consider the following:
Some apple varieties, such as Cox's Orange Pippin, Delicious, Fuji, Braeburn and Jonathan, are more susceptible.
It’s more common when fruit is picked when over-ripe.
Low calcium levels in the fruit can exacerbate the problem. However, calcium availability is complex and it’s not as simple as ensuring there’s enough calcium in the soil. Irrigation, soil pH, magnesium levels (remember my Epsom salts post) and all sorts of factors can affect calcium levels in the fruit.
Environmental conditions (particularly sudden onset of cold weather) can increase the problem.
Water stress can cause the tree to rapidly move sorbitol from the leaves to the fruit and increase water core symptoms.
Nitrogen levels in the soil may also play a role.
It could be any combination of these points, but the water stress is where my money would be with the dry conditions we’ve had this year.
The good news is that fruit affected by water core is still fine to eat. It’s just that affected fruit probably won’t cold-store for very long. Unfortunately, there’s no way to tell from the outside which fruit is affected and which isn’t. So you will be best to eat what you can fresh and then focus on dehydrating or bottling any you want to store long term.
Different apple trees of mine have been affected to a different extent each autumn. So hopefully this won’t occur for you every year.
Reduced rotations require strong seeds
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Colette B., Gawler, SA