Document Type : Research Paper
Authors
1
Agricultural Research, Education and Extension Organization, Horticultural Sciences Research Institute, Temperate Fruits Research Center
2
Agricultural Research, Education and Extension Organization, Horticultural Sciences Research Institute, Temperate Fruits Research center, Karaj, Iran
Abstract
Cacopsylla pyricola Foerster is one of the most important pests affecting pear production. The main purpose of this research was to investigate the resistance of the best pear cultivars to pear psylla for the recommendation in the integrated management program of this pest. This research was conducted for four years between 2019 and 2023. For this project, nine cultivars were used: Boheme, Shah Mieveh, Natanzi, Sebri, Darghazi, Beiruti (Louisbon), Harvest Queen, Potomac and Cosia. The collection of information about the population of different psyllids, eggs, nymphs, and dult were done at the peak of its activity, i.e., from early February to November, every 7 days. The indices of antixenosis resistance included the Attraction Index, Mean crowding intensity, Relative abundance establishment rate, Non-preference index and Prevalence index of eggs, nymphs and adults. The characteristics of the tree form, one-year branches, current branches, leaves, flowers and fruits were examined. In order to separate the cultivars based on the degree of sensitivity to pear Psylla, cluster analysis was used. The relationship between the traits of pear cultivars and the occurrence of antixenosis mechanisms was done through correlation analysis. The results showed that the most resistant cultivars to pear Psylla included Cosia, Boheme, Sabri, Natanzi and Potomac. Egg/nymph/adult atteraction index is 0.99, 0.99 and 0.95, crowding intensity index is 58.30, 149.14 and 16.13, the relative establishment rate 3.68, 3.65 and 3.40 egg/nymph/adult, the non-perference index of 98.04, 98.06 and 19.98 and the prevalence index were 49.66, 49.47 and 47.50, for egg/nymph/adult respectively.
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