ارزيابي مقاومت نسبي ارقام تجاري بادام نسبت به بيماري لكه آجري در استان چهارمحال و بختياري

RELATIVE RESISTANCE OF SELECTED ALMOND CULTIVARS TO THE CAUSAL AGENT OF RED LEAF BLOTCH DISEASE, IN CHAHAR MAHAL-VA-BAKHTIARI PROVINCE

Almond red leaf blotch caused by Polystigma amygdalinum, is one of the most important leaf disease of almond. In order to evaluate relative resistance of commercial almond cultivars to P. amygdalinum, 20 cultivars of 2 year-old- almond seedlings were planted in a randomized block design with 3 replication (3 plants in each replicate) in Chahar-Takhteh Station in Shahr-e-Kord. Overwinterd infected almond leaves were used as inucula in each plot. In order to maintain proper moisture for the release of ascospores, all planted trees irrigated daily with sprinkirrg system for 0.5-1 hour, from the time of leaf emergence to complete leaf maturity. Sampling were carried out at the time of maximum lesion expanded. Relative resistance was acs&ssed based on disease intensity and percent of leaf infection. The results showed that there are significant difference among cultivars.Cultivars of Frragness, Shekofeh , Shalurud-12 and Shahrud-6 were highly resistance,where as, Emamieh l. Shahrud-l6, Shahrud-7 and Shahrud-19 cultivars were susceptible.