The phenomenon known as "kiwifruit vine decline" was reported in Verona for the first time in 2012. In 2016, over 1,000 hectares have already been dug up. The disease was also observed in Piedmont for the first time in 2015.
At first, the plants in a certain part of the orchard wither, then slowly all the trees die. Usually the disease spreads in just one season.
The big roots are the ones that get hit first. Their colour turns reddish-brown and they lose their absorbing function.
Left: tree with a suffering root system. Right: big rotting root.
Initially, the leaves wither, then they become necrotic and die. The production of fruit is completely compromised.
A technical note on kiwifruit vine decline by Agrion technicians Graziano Vittone and Luca Nari was published on 26th August 2016. As the damage caused by the PSA since 2011 is still fresh on everyone's mind, the technicians are working with other bodies to identify the causes of this phenomenon, which does not look like it is being caused by a pathogen.
"Biotic causes have been excluded - 75% of planting tests remained fertile, confirming the theory that the tissue is altered by a physical factor rather than by a parasite, so all treatments against root rot are useless."
The attention must therefore turn towards the water and soil.
Agrion technicians advise 1) checking the state of the roots; 2) using tensiometers and other tools to assess the water in the soil; 3) checking the irrigation system used (water quantity and operative times).
Contacts:
Graziano Vittone e Luca Nari
Agrion - Fondazione per la ricerca l'innovazione e lo sviluppo tecnologico dell'agricoltura piemontese
Manta (CN)
Via Falicetto, 24
12030 Manta (CN)
Tel.: (+39) 0175 1953030
Email: [email protected]
Web: www.agrion.it
