Abstract:
For the purpose of study, Barani Tract of Punjab (Pakistan) was divided into four zones on the basis of annual rainfall. The zones comprised of very low annual rainfall, i.e., 150-300 mm (zone I), low, 300-500mm (zone II), medium, 500-1000 mm and high, 1000-1500 mm annual rainfall (zone IV). In each zone the weed density by species was observed 4-6 weeks after sowing (WAS), for two consecutive years. (Weeds grown during this period are considered more competitive). Highest numbers of weed species were found in zone III, whereas their density remained highest in zone IV. Zones I and II were holding less number of weed species with low densities as compared to those of zones III and IV. On the basis of density at 4-6 WAS, Convolvulus arvensis and Asphodellus tenuifohus in zone I and zone II are the first two competent weeds. In zone III, Fumaria indica emerges during this period with highest density. Medicago polymorpha and Melilotus indicus are the next two important weeds. In zone IV (high rainfall) Veronica didyma and Lamium amplexicaule emerge during the early period of 4-6 WAS, and that too in high density.
Page(s):
21-25
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Science, Volume: 50, Issue: 1--2, Year: 1998