DIVERSITY OF WEED FLORA IN ONION FIELDS OF PUNJAB, PAKISTAN

ABSTRACT Weeds are serious management threat for onion (Allium cepa) production but very little information is available on their distribution frequency in various agro ecological zones of Pakistan. The information for weed distribution and its associated factors for crop production technology and effect of weed frequency and its impact on plant stand quality and yield were observed. A total 33 weeds belonging to 16 angiosperm families were noted in onion fields that included Amaranthus hybridus, Amaranthus retroflexus,Anagallis arvensis, Atricaria chamomilla, Avena sterilis, Capsella bursapastoris, Carduus nutans, Chenopodium album, Chenopodium murale, Convolvulus arvensis, Cyperus rotundus, Digitaria sanguinalis, Euphorbia prostarta, Fumaria indica, Galium aparine, Lactuca serriola, Lolium temulentum, Malva sylvestris, Medicago polymorpha, Polygonum aviculare, Papaver rhoeas, Parthenium hysterophorus, Poa annua, Rumex dentatus, Setaria verticillata, Silybum marianum, Sinapis arvensis, Solanum nigrum, Sonchus asper, Sonchus oleraceus, Sorghum halepense, Stelleria media, Vicia sativa and Xantium strumarium. The highest weed invasion was in suburban areas where onion was grown on commercial or house hold consumption basis while lowest weeds frequency was in urban areas where small kitchen gardening was done. Plant health quality was affected even at 18-20% distribution frequency describing the collective performance of weeds on agronomic traits of onion crop. Poaceae and Papaveraceae family weeds proved more harmful for onion plant stand, yield quality and all of the test parameters. Several factors can affect the overall growth and development of weeds (Kashmir et al., 2016). [...]a systematic study was conducted in onion growing district of Punjab, Pakistan to focus the dissemination of different weed...