Winter sunscald as a predisposing factor for bacterial canker of almond and peach trees in Chaharmahal va Bakhtiari province

Winter sunscald is a physiological disorder that causes damage to almond and peach trees in some orchards of Chaharmahal va Bakhtiary province. In orchards with favorable conditions for this disorder bacterial canker was more severe observed. Early symptoms consist of discolored bark, similar to a canker, and some small vertical cracking in the bark. As time progresses, bark will begin to slough off, the death of the trunk and dieback. Symptoms can be seen on the south and southwest sides of the trees. The relationship between winter sunscald and bacterial canker of almond and peach in Chaharmahal va Bakhtiary province was investigated during 2016-2019. This study was conducted in 12 selected peach and almond orchards in different areas of the province. In almonds, disorder index on the southwest side of the trees increased by 83% compared to the northeast side of the trees, while in peaches the increase was about 82.7%. Frequency of isolation of Pseudomonas syringae pv syringae (bacterial canker agent) on the southwest side of the trees was about 78.4% and 75% higher for almonds and peaches, respectively. The southwestern white painting treatment of the trunk compared to the control showed that in almonds it decreased sunscald and canker symptoms in almonds70 to 81% and for peaches56.3 to 86%. So, it can be said that winter sunscald is causes of decline and plays role as a predisposing factor for e bacterial canker of almond and peach trees in Chaharmahal va Bakhtiary province.