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INTRAANNUAL VARIATIONS IN WEED COMMUNITIES OF LENTIL FIELDS IN CHAKWAL, PAKISTAN

SIKANDER SULTAN^* AND ZAHEER AHMAD NASIR¹

Abstract: Weed communities are never static nor are they necessarily at equilibrium as they change in response to external and internal forces. To identify the ecologically operative weed communities, two surveys were carried out at eight sites in lentil fields of District Chakwal during 1999-2000. Twenty nine weed species in 1999 and 36 weed species in 2000 were recorded from the study area. Based  on the  importance value, 8 weed communities viz, 1) Asphodelus – Sorghum – Convolvulus in Bhaun; 2) Asphodelus – Carthamus – Fumaria in Dudyal; 3) Fumaria – Asphodelus – Launaea in Pindi Gugran; 4) Sorghum – Medicago – Carthamus in Balkasar; 5) Sorghum – Pentanema – Centaurea in Dulmyal; 6) Carthamus – Emex – Asphodelus in Jahtla; 7) Asphodelus – Carthamus – Cousinea in Kot Sarang; and 8) Asphodelus – Carthamus – Convolvulus in Taman were recognized during 1999. Whereas in 2000 another 8 weed communities viz., 1) Lathyrus – Anagallis – Vicia; 2) Chenopodium – Medicago – Fumaria; 3) Asphodelus – Vicia – Convolvulus; 4) Asphodelus – Fumaria – Carthamus; 5) Asphodelus – Convolvulus – Pentanema; 6) Asphodelus – Medicago – Convolvulus; 7) Carthamus – Convolvulus – Sorghum; and 8) Carthamus – Convolvulus – Asphodelus were recognized in these sites. Asphodelus tenuifolius, Carthamus oxycantha, Fumaira indica, Medicago denticulata, Convolvulus arvensis and Sorghum halepense were important dominants in different capacities. An interspecific population shift in weed communities was observed during the growth season of the crop.
 

Department of Microbiology & Molecular Genetics,  University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan
¹Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, Essex, UK.