This is junk science because…
… at the very least, the claim is based on two apple orchards in Japan, which is not a leading producer of apples.
Channel News Asia reports:
Global warming is causing apples to lose some of their crunch but is also making them sweeter, a study said Thursday.
Analysing data gathered from 1970 to 2010 at two orchards in Japan, a research team said there was clear evidence that climate change was having an effect on apple taste and texture.
“All such changes may have resulted from earlier blooming and higher temperatures” during the growth season, they wrote in the journal Nature Scientific Reports.