بررسی ساختار جوامع و ترکیب گونه‌ای علف‌های‌هرز مزارع گندم آبی استان فارس

The first and most important step in managing and controlling weeds is to know the flora and structure of communities and their geographical distribution. In order to identify and determine the structure of weed communities in the wheat fields of Fars province, a study was conducted during the years 2023 and 2024 in 16 major and important wheat planting cities from different parts of the province including: Marvdasht, Darab, Fasa, Eqlid, Kazerun, Mamasani, Kavar, Abadeh, Sarchehan, Firouzabad, Larestan, Khorram bid, Juyom, Kharameh, Estahban and Khonj were conducted from 144 farms and the density and species composition of weeds in the farms were determined. 102 species from 23 plant families were identified in these farms. Three plant families Brassicaceae, Asteraceae and Poaceae accounted for the most species with 21, 17 and 14 species respectively (51% in total). According to the abundance index of ryegrass (Lolium rigidum), wild oat (Avena ludoviciana), field bindweed (Convolvulus arvensis), little seed canary grass (Phalaris minor), cleavers (Galium aparine), prostrate knotweed (Polygonum aviculare), wild mustard (Sinapis arvensis), rye (Secale cereale), wild barley (Hordeum spontaneum), annual yellow sweet clover (Melilotus indicus), mallow (Malva neglecta), shortpod mustard (Hirschfeldia incana) and oriental knight’s-spur (Consolida orientalis) as important weeds of the province, respectively, had the highest frequency in the monitored fields. Ryegrass is the most important weed in the wheat fields of Fars province in the southern and southeastern cities of the province (Darab, Larestan, Juyom, Khonj, Fasa) with a hot and dry to semi-hot climate and some central areas (Firouzabad, Kavar, Estahban and Marvdasht) with a semi-temperate climate had a high distribution. The average density of this weed in the mentioned areas varied from 10.4 to 142.72 plants per square meter. In the northern regions of the province (Eqlid, Abadeh, Khorram bid, Sarchehan) with cold weather, broad-leaf weeds, especially cleavers, oriental knight’s-spur, hare's ear mustard (Conringia orientalis), greater bur-parsley (Turgenia latifolia) and field bindweed were more density and important. In some of these areas, narrow leaves such as rye and rough bluegrass (Poa trivialis) also had a high density. In the western regions of the province (Mamasani and Kazerun), some broad-leaved species such as scarlet pimpernel (Anagalis arvensis), fineleaf fumitory (Fumaria parviflora), lambsquarters (Chenopodium album), cleavers, and wild barley (Kazerun city) they were more dominant. Waxy leaved mustard (Isatis quadrialata) as a new weed was observed for the first time in Fars province from Abadeh and currently its distribution is limited to this city.