برآورد اولیه تاثیر تناوب زراعی بر جمعیت گروه‌های مختلف تغذیه‌ای نماتدها در مزارع پروژه ملی گندم بنیان موسسه تحقیقات کشاورزی دیم کشور (مراغه- استان آذریابجان‌شرقی)

Crop rotation is one of the oldest and most important methods of plant parasitic nematodes control. Due to the disadvantages of using chemical compounds to nematodes management, the importance of paying attention to crop rotation has increased and in many cases it has become a common method for manageming of plant parasitic nematodes. In order to investigation the effect of crop rotation on the population of different feeding groups of nematodes, sampling was carried out from the fields of National Wheat Project - Dryland Agricultural research Institute (Maragheh -East-Azerbaijan) which has been under different crop rotation during past years by cultivating various common suitable crops for dry and cold rainfed areas, including various wheat and pea cultivars. This experiment was performed in the form of a randomized complete block with three treatment and three repetitions (polt), each plot size was 90 × 20 m. Wheat (Homa cultivar) - green fallow without tillage - wheat (Baran cultivar) scenario was selected as a control. Sampling from control and two other scenarios (a): wheat (Homa cultivar) - pea (Anna cultivar) -green fallow without tillage and (b): wheat (Baran cultivar) - pea (Anna cultivar) (each in three repetitions) were performed, too. Taking samples was carried out randomly by five soil samples weighing approximately one kilogram from the depth 30 cm in a zigzag path, then the samples of each plot were mixed together and a sample with one kg weight was taken. After transferring the soil samples to laboratory, the nematodes were extracted from the same volume of soil (200 cm3) using a tray method. The nematodes were then counted under the same conditions (seven repetitions and one replication of one milliliter of the extracted solution) using a stereomicroscope. After counting, statistical analysis was performed using STATISTIX 10 software. Analysis of the variance of the converted data showed that there was a significant difference in the number of plant parasitic nematodes and bacteriophagous at different levels of 1% and 5% probability, respectively, meanwhile it was not any different between predators and dorylaims. However, there was a significant difference between predators and dorylaims of the blocks. Comparing the mean with LSD, it was found that the number of plant parasitic nematodes in chickpea rotations was significantly higher than the control, but there was a significant difference between treatments with chickpeas in rotation. The bacteriophagous nematode population was also significantly higher in the pea-free rotaion (control). These results show that crop cultivation is effective in increasing the population of different feeding groups of nematode