تاثیر چهار قارچ‌کش بر شدت بیماری سوختگی آلترناریایی پسته

Pistachio as a strategic product has a special place among Iranian agricultural products and has a major role in non-oil exports. Various diseases such as Alternaria late blight affect pistachio production in the world and of course in Iran. The main causal agent of this disease is Alternaria alternata (Fr.) Keissl. One of the most important ways to control Alternaria late blight is using fungicides. Pyradim ® DF with pyraclostrobin+dimetomorph active ingredient is a new fungicide. In the present study, its efficacy was evaluated in comparison with fungicides Captan ®(captan WP50%), Nordox®(copper oxide WG38%), Mishocap® (copper oxychloride WP35%). The experiment was carried out in a Randomized Complete Block Design (RCBD) with 8 treatments and 4 replications in Markazi (Zarandieh), Kerman and Semnan provinces with natural infection. At harvest, the treated trees were examined and sampled from the clusters to assess the incidence and severity of the disease. Disease incidence percentage and disease severity percentage were analyzed using SAS software. Mean comparison of disease severity and disease incidence percentages were done by Duncan's multiple range test. The results showed that Pyradim with dosage of 1 and 0.75 per thousand has a good efficacy in controlling pistachio Alternaria late blight disease. Captan fungicide also had acceptable efficacy in controlling pistachio Alternaria late blight disease. In contrast, Nordox and Mishocap fungicides did not have good efficiency and except Nordox, which was 60% effective in Markazi province, in other areas, the effectiveness of these fungicides was less than 50%.Therefore, in general, it can be said that since the dose of 0.75 g L-1 of Pyradim fungicide has a good efficiency in controlling pistachio Alternaria late blight disease and there is no statistically significant difference with 1 g L-1 of Pyradim, also, the recommended dose of the company is 0.75 g L-1. Therefore, 0.75 g L-1Pyradim is recommended for controlling Alternaria late blight disease.