Preeharvest treatments of fruit
In order to obtain big fruits of high quality, there is a need to thin fruits. As in many other fruit
species there is a negative correlation between the number of fruits and their size. Even distribution of fruits on the branches is desired: about 5 fruits on a group of small branches with a good (20 cm) distance between the fruits. Where a group of fruits develops, the touching fruits are removed. If fruits touch each other, the touching place has favourable conditions for development of insects.
From their local experience, farmers know how much they can load the tree without influencing fruit size. For example when a farmer has 400 trees per hectare (6×4 planting distance) and is aiming for 30 tons of 500 g fruits each, he will need 150 1⁄2 kg fruits per tree at harvest. The fruits should be well distributed in the canopy. Some farmers thin more than once.
In order to obtain fruits without damage to the rind and with good colour, some farmers clean the small branches around the fruits which might scratch the fruit. By doing this they also expose the fruit to sunlight. There is an idea to use reflective plastic sheets underneath the foliage to improve colour. This has not yet been experimented.
The main disorder which causes a severe economic impact is splitting of ripe fruit. The damage can be even of half of the yield.
Regular irrigation can decrease the damage. However regular irrigation as is done in the
commercial orchards in Greece does not prevent it completely.
Some growers claim that if they leave more fruits on a tree the phenomena is bigger, and that
thinning helps to reduce it. Another explanation is that when they leave more fruits per tree and wait for it to attain regular size, the grains swell and crack the rind.
Another damage is the sunburn on fruit rind which reduces its value. The damage happens only at a certain physiological stage of fruit development. In cvs which have a willowy canopy there is no damage.
Harvesting, packing and storage
As mentioned before, more than in other fruits, pomegranates are used for decorative purposes. Therefore the most important criteria for beginning of harvesting is the external appearance, mainly the colour but also the "fullness" of the fruit.
For some reason the sour cvs are red, while the sweet ones are more pinkish or greener.
Generally when a cv. starts to be harvested in Greece its eating quality is not good enough. It is improved later on. Fruits of early cvs are harvested selectively, while late cvs are harvested all together.
When harvested, stalkless fruits are arranged in plastic boxes so that the stalk will not damage it’s neighbouring fruit. As the fruit crown should be kept unharmed the fruits are put manually on the weighting plate of the grading machines – avoiding the elevator and singulator parts. After careful observation of external appearance fruits are packed according to size in 21⁄2 kg cardboxes for export and around 8 kg for the local market.
When supply is bigger than the demand, and for prolonging the season, fruits can be stored in cold storage. Fruits are kept at 7 C and 90% R.h. Only clean fruits with no insect damage, especially clear of criptoblabos gnidiella damages, are stored. Fruits damaged by the insect may rot in storage.
Fruits can be easily stored for a period of 3 months. If the stored fruit is not mature, external
browning of the rind occur. Pomegranates can be stored in the ambient conditions for quite a long time. The rind dries and turns brown but the inside grains are kept well.
Needs for the future
In many countries, the pomegranate which is a traditional crop, or a new crop, needs more
investment in research and development. In order to base the knowledge on sound ground, such are the needs for fertilising, for irrigation and for other horticultural practices.
More environmentally-friendly plant protection practices have to be developed, as the markets
demand cleaner (from pesticides) fruits, than it obtains today.
Better cultivars, of higher internal quality of fruits, have to be cultivated. Standards of quality are needed in the markets. Cooperation in research, development and exchange of the existing knowledge are some of the first steps towards better production and products.