Phyto-Sociological Studies of Kharif Season Weeds with Special Reference to Oxalis latifolia in U.P. Hills

A phyto-sociological survey was conducted in all the eight districts of Kumaon and Garhwal regions of V.P. hills during kharlf 1989 and 1990. The data revealed that major weeds found in rainfed kharif cropswere: Oxalis latifolia, Cyperus rotundus, Galinsoga parviflora, Digitaria ciliaris, Poligonum capitatum, Commelina benghalensis, Setaria glauca, Echinochloa colonum, etc. Among these weeds, O. latifolia recorded highest distribution (22.36%), density (168.48/m2), relative dominance (31.91%) and absolute dominance (0.90), while the C. rotundus had maximum frequency (73.05%). O. latifolia, which iscommonly known as tipatiya, was firstly introduced into V. P. hills as rabbit feed about 200 years back. Its spread from the place of introduction was mainly through fodder grasses via farm-yard manure. Presently about 33.53% of the total cultivated area and 56.0% of the total villages in V. P. hills found to be affected by O. latifolia weed.