Density and prevalence of weed species in pistachio orchards of Siirt province

Abstract

In this study, we aimed to determine the weeds and their prevalence and densities in pistachio gardens of Siirt province. Survey studies were carried out in the 2017-2018 vegetation periods. In the scope of the study, a total of 103 pistachio orchards were randomly selected to represent the region. As a result of survey, a total of 170 weed species belonging to 37 families, including 4 monocots and 33 dicots were recorded. The highest number of weed species were belong to Asteraceae (29 species), Poaceae (23 species), Fabaceae (18 species), Apiaceae (12 species) and Brassicaceae (12 species). Among the identified weed species; Avena spp., Anchusa azurea Miller., Bromus tectorum L., Cardaria draba (L.) Desv., Carduus pycnocephalus L., Fumaria officinalis L., Lamium amplexicaule L., Lactuca serriola L., Galium aparine L., Lolium perene L., Medicago sativa L., Papaver rhoeas L., Sinapis arvensis L., Thlaspi arvense L. and Vicia sativa L. were the most common species that have highest frequency of occurrence. The species have the highest density in the region were Cynodon dactylon (L.) Pers. and Convolvulus arvensis L. The overall coverage area of the weed species in pistachio orchards of Siirt province was determined as 37%. However, the number of weed species, their frequencies and densities and the coverage areas were found to be highly diverse among the districts. The highest percentage of weeds was found in the Siirt center with the rate of 53%, while the lowest rate was found as 19% in Baykan district. Eruh (155 species) district had the highest number of weed species, while the lowest number of weed species was recorded in Baykan (76 species) district. The results revealed that region specific weed management strategies should be applied in the study area.