AusBonsai

starting harvest this week-we supply a fresh domestic market and this fruit shows no indication of this problem until it's cut- so far about 10% of samples are affected--there are no signs of insect activity-no eggs or grubs-trees seem normally healthy- my thoughts-possibly heat or water or nutrient stress-or problem at flowering --no real idea at the moment---.may cause us to abandon the crop for this season---any ideas or pointers appreciated.----Guy

I would of thought it was some kind of grub doing this. I get this in some apples if I don't spray them but that is from codling moth I believe
https://en.wikipedia.org/wiki/Codling_moth

thanks for the reply Matthew--- I have considered codling moth but there is no evidence of any grubs being present---no skin blemishes or holes into the fruit--the internal is dry ,similar to galls caused by sun damage but nowhere near the skin--
it's got me 'flummoxed'

The likely culprit seems to be (possibly) Alternaria alternata

The infection can occur at flower senescence.


https://www.google.com.au/search?q=alte ... =933&dpr=1


http://www.extento.hawaii.edu/kbase/cro ... _alter.htm

thanks treeman -will check that out