A SURVEY OF DAMAGE OF CITRUS IN THE MAZANDARAN REGION OF IRAN FOLLOWING THE JANUARY 2008 FREEZE

Regions of northern Iran were hit by an unusually bad cold snap in January 2008. Temperatures in the Mazandaran region dropped from 7 to -6°C and to -12°C in some coastal areas.
After 10 days of heavy snowing and 20 days of cold weather, citrus trees were severely damaged.
We evaluated citrus trees and fruits to determine the extent of damage.
Frost damage resulted in symptoms on the fruit skin, bitter taste of the fruit juice and fruit drop.
Medium and small fruits with sugar contents higher than 13% and those orchards which were not irrigated well during the summer showed less damage.
However, in total 800,000 tons of oranges were destroyed.
Trees from 1-5 years old of all kinds of citrus died completely.
Almost all limes and lemon died completely.
Among oranges cultivars, ‘Thomson Navel’ orange sustained less damage but ‘Shamooty’ orange died entirely. ‘Hamlin’, ‘Frost Navel’, and ‘Valencia’ orange had up to 50% shoot burn.
The least damage was observed in ‘Wase’ mandarin.
Hardiness ranking were: mandarins > oranges > grapefruits > pummelos > limes and lemon.
Trifoliate oranges and citranges were not affected by the freeze but dieback was observed on sour orange.
Young trees 20 to 100 m a.s.l. were completely destroyed, whereas trees at 200 to 300 m elevation were not affected.
Between 100 to 200 m elevation, frost injury depended on cultivar.
In western Mazandaran, the combination of cold and heavy snow resulted in broken branches on up to 50% of trees in an orchard.

IX International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems

H. Sadeghi, A. Ghanbari

tree death, hardiness, fruit quality, elevation, rootstock, orange, grapefruit, mandarin, lemon, lime, pummelos

https://doi.org/10.17660/ActaHortic.2011.903.162