Split PIts
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Identification
Split pit
- Opening or split of the pit at the stem end of the fruit
- Develops during final swell, the third stage of fruit growth
- Immature fruit that have abnormal shapes or sutures often manifest split pit symptoms during final swell
- Most common in early-maturing varieties but can occur in later maturing varieties
- Fruit with split pit generally develops rot much faster than sound fruit
- Fruit with visible split pits at the stem end may also have fractured pit halves and considerable gumming in the pit cavity
- Prone to rot problems, and rots can spread rapidly from split pit fruit to sound fruit
Pit shattering
- Pit breaks into multiple pieces
- Associated with internal gumming
- More common in malformed fruits but occurs in fruit that appear normal
- Primarily at the blossom end of the fruit
Biology
The causes of pit breakage are poorly understood. Cold or freeze damage during flowering and early fruit development seems to promote split pits. Rainfall is not responsible but may aggravate split-pits. There has been no consistent association between micro nutrient status deficiency or excess, in trees and split-pits. It appears that anything that upsets the carbohydrate balance between leaves and roots can increase the split-pit problem. This includes winter injury, girdling, high heat, heavy watering, excess vigour, or trunk damage. Rapid growth of fruit is frequently associated with split pits.
Early peach varieties frequently enter their final swell of growth before complete hardening of the pit has occurred. However, the weakening of the pit that leads to the splitting probably occurs in the latter stages of pit hardening. Rapid fruit enlargement causes, or worsens, much of the pit fracturing that occurs. Most early varieties are clings or semi-freestone, so the strong attachment of flesh to pit may contribute to the problem.
In mid- and late season varieties, pits have more structural integrity because they have properly lignified and hardened before pressure is exerted by the flesh during the final growth stage.
Shattered pit-gumming problems are much less common in fruits with viable seeds. It is not known if the pit shatters because of seed death or if a breakage of the pit actually causes the seed death.
Management Notes
Plant varieties that are not prone to split pits.
Do not thin fruit on problem varieties excessively.
Avoid excessive nitrogen applications, especially close to harvest time.
Use stricter packinghouse grading for problem varieties to remove misshapen fruit. These fruit are most at-risk for split pits.
Avoid thinning fruit during the pit hardening stage. Thin only once pits are hard.
Avoid irregular watering during the pit hardening stage.
Avoid long irrigation sets during 4 – 6 wks prior to pit-hardening.
Blossom thinning may induce better size while minimizing split-pit, because earlier thinning may promote cell division and secure the possibility of better fruit growth after the risky stage.
Some information included above excerpted from;
http://www.ipm.ucdavis.edu/PMG/GARDEN/FRUIT/ENVIRON/pchsplitpit.html
