| The influence of alternate bearing (ON/OFF year) on population of common pistachio psyllid (CPP), Agonoscena pistaciae (Hemiptera: Aphalaridae), in central Iran |
| Paper ID : 1214-3IICE (R1) |
| Authors: |
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hossein dehghani yachdani *1, Shahzad Iranipour2, Mohammad Reza Mehrnejad3, Reza Farshbaf pourabad4 1plant protection, agriculture, university of Tabriz 2Department of Plant Protection, Faculty of Agriculture, University of Tabriz, Tabriz, Iran 3pistachio Reserch institue 4Department of Plant Protection, Faculty of Agriculture, University of Tabriz |
| Abstract: |
| Abstract Pistacia vera Linnaeus (Sapindales: Anacardiaceae) is a plant with a characteristic biennial production system. It means that following a high productive year, a pistachio tree rests in subsequent year. This physiological phenomenon is addressed as ON/OFF year by farmers. It is believed that outbreaks of common pistachio psyllid (CPP) occur at ON years. In order to test above hypothesis and provide evidences to support or reject it, a study was conducted in Maybod county, Yazd province in 2016. The abundance of CPP eggs and nymphs was recorded in four pistachio orchards on six pistachio trees of the same age, same cultivar and same production measures, three of which were fertile (ON year) and three were infertile (OFF year). Regular weekly samples were taken for 28 times during the growing season. Four fully matured apical leaflets were cut with a scissor from four geographical sides of the trees, 2 m above the ground level. After transference to the laboratory, the number of nymphs, eggs and parasitized nymphs of common pistachio psylla on the upper and lower parts of the leaflet was counted and summed over the four directions. Number of eggs and nymphs were subjected to one-way ANOVA to test whether abundance were similar in all orchards and between ON/OFF year trees. The results revealed a significant difference in the abundance of eggs and nymphs at different locations (F=5.062; df=3, 20; P-value=0.009 for eggs; F=18.747; df=3, 20; P-value<0.001 for nymphs) but there was no significant difference between trees in ON and Off years (F=1.93; df=1,22; P-value=0.178 for eggs; F=0.09; df=1,22; P-value=0.767 for nymph). These results do not support common belief of relation between outbreaks and production status of pistachio trees. |
| Keywords: |
| Pistachio psyllid, alternate bearing, population |
| Status : Paper Accepted (Poster Presentation) |
