Udine September 20, 2011

Harvesting and Storage

Fruit are harvested when soluble solids content (SSC) reaches 8 °Brix. Such a sugar content is generally reached in the first fifteen days of October, with differences according to the growing area and the season.
The harvest can be delayed up to 12-14 ° Brix, corresponding to the almost complete ripening of fruit in plant.
Earlier harvests with SSC below 8 ° Brix are not advised because of the scarce quality of fruit offered to the consumer.
Fruit with SSC between 8 and 10 ° Brix can be destinated to relative long storage, up to 4-6 months (February-April in the Northern hemisphere). Fruit collected at higher SSC (above 12 ° Brix) are either delivered to the market or keept for a short storage, no longer than 2-3 months. Fruit collected in advanced ripening stage need all the same a layover of at least one week in the cold store before they are delivered  to the market.
Fruit storage at normal atmospheres (NA) is limited to few months, while controlled atmosphere (CA) with ethylene removal can prolong the storage life up to 6 months.
We recommend curing the fruit by holding them in the shade for at least 48–72 hours before storage in the coolstore. This reduces the incidence of Botrytis during storage, possibly by sealing the picking scar or wound. Curing can help protect also against other postharvest disorders.
There is no specific data about parameters for ‘Soreli’ CA storage. General recommendations on kiwifruit storage should therefore be followed.


Udine May 11, 2011

PSA bacteriosis on kiwifruit

All tests for the presence of Pseudomonas syringae pv. actinidiae (PSA) on the mother plants of ‘Soreli’ and ‘Belen’, the kiwifruit cultivars released by the University of Udine, have proved negative.

The University of Udine (UNIUD) submitted mother plants of ‘Soreli’ (female) and ‘Belén’ (male) selections to test for the presence of PSA. These tests were carried out by the Regional Phytosanitary Service (SFR). All tests were negative and the mother plants held at the University Experimental Farm can be considered until now as being free of PSA. We can therefore reasonably assume that up to now licensees have been provided with healthy budwood.

There have been widespread rumours that kiwifruit cultivars vary in their susceptibility to PSA. UNIUD scientists want to emphasise to licensees that these are rumours only without foundation and that only trials, comparing different kiwifruit cultivars under the same conditions, would answer the question. What is clear is that the cultivars available to western growers are all more or less susceptible to PSA. The greatest differences are seen between mature orchards, where the disease spreads more slowly, and the young or very young orchards, where the attack by the virulent strain of PSA is often devastating. Obviously, information on ‘Soreli’ is rather limited owing to the recent release of the cultivar and to the small number of orchards that can be observed.

Vine removal, imposed to reduce the bacterial inoculum, is an issue that concerns both growers and nurseries. The University of Udine wants to emphasise two very important aspects of disease control: (a) removal of orchards and vines, being compulsory, must be accompanied by financial support to growers as this would encourage them to collaborate with the Phytosanitary Services; (b) nurserymen should be considered in the same way of growers and they should not be considered just as spreaders of disease. Nurseryman are the first victims of the PSA disease and there is a risk they will suffer more financially than others from the ban on their activities and the ban on new orchards imposed by several local governments.

Considering the recent governmental decree (DM February 7, 2011 issuing measures to prevent, control and eradicate the kiwifruit bacterial canker caused by Pseudomonas syringae pv. actinidiae), scientists of University of Udine support the recommendations proposed in Attachment I (action plan to control the disease). As for Attchment II (regulation on kiwifruit propagation), the University of Udine is coordinating with the SFR of Friuli Venezia Giulia. However, the UNIUD scientists have concerns with the decision of the Ministry of Agriculture to require mother plants to be freed of viruses (Attachment III). UNIUD scientists would stress that the scientific community has increasing concerns about the risk of exposing such ‘cleaned plants’ to pathogens once they are in the field.

UNIUD scientists support the recommendations of the Regional Phytosanitary Services that are all in agreement with the Attachment I of the Government decree cited above, but they are concerned by the information that has appeared recently in grower magazines about the control of the disease, as this is causing growers to become confused.

UNIUD scientists are working towards setting up a PSA research project coordinated at the national level , but the situation is currently rather confused and the work carried out up to now is poorly funded and totally uncoordinated, as any grower attending scientific meetings on PSA in different regions must have noticed.