Fruit samples taken over the past several weeks from an orchard in Marion County have shown some progression of pit splitting. Symptoms were first noted on fruit samples taken on 3/23/2018: Notice the small hairline cracks within the developing pits in the right half of the photo.
Another sample from 3/29/2018 with the seed removed shows the signs more clearly:
Here are additional photos taken of samples from 4/4/2018. It was incredible to see the rapid change in size, skin color, and flesh color development within the last week of these fruit with pit splitting.
When does pit splitting happen and what are the potential causes?
This disorder can appear as early as a few weeks after bloom and occur through the pit hardening stage. Although the direct cause is still unclear, factors that can contribute to splitting include:
Early ripening cultivars: This may be due to the more rapid fruit growth compared with later ripening varieties. There is good correlation between rate of growth and pit splitting.
Genetic cause: Pit splitting may be a characteristic trait expressed more in one variety than another. Two genes have been identified as being expressed during fruit growth, and may lead to further insight.
Environmental: Below freezing weather or high heat, and excessive rainfall within short period of time during critical stages can contribute.
Cultural practices: Excessive irrigation, thinning, and fertilizing can contribute by changing the available resources the growing fruit has to draw from, and the rate of growth.