CAMPARATIVE STUDY OF WEED SPECIES RECORDED IN DIFFERENT FIELD CROPS OF BANNU, KHYBER PAKHTUNKHWA, PAKISTAN

Relative density of weeds, found in different fields of cereal crops (wheat, rice and maize) and sugarcane (a cash crop) of district bannu was determined by using the oosting scale method during 2013. in this research work, a total of 135 weeds belonging to 37 families were collected, identified botanically, preserved and documented. results showed that 20 species belonged to asteraceae which comprised 54% of the whole collected weeds followed by 19 species of poaceae (51%), eight species each of solanaceae, amaranthaceae and boraginaceae (21%). seven species were recorded each from papilionaceae, euphorbiaceae and brassicaceae (18.9%), five species from polygonaceae and malvaceae (13.5%), four from chenopodiaceae and three from plantaginaceae which were 10.8 and 8%, respectively. about 5.4% contribution was made by asclepiadaceae, convolvulacea, caryophyllaceae, cucurbitaceae, genetaceae, apiaceae, and verbenaceae with two species each. the remaining seventeen families (aizoaceae, cyperaceae etc.) were represented by 2.7% with only one species each. there were seven weeds found in all of the above mentioned crops which were cirsium arvense, convolvulus arvensis, conyza bonariensis, cynodon dactylon, cyperus rotundus, parthenium hysterophorus, and sonchus aspera. according to the oosting scale, the very abundant weeds in sugarcane fields were leptochloa panicea, enneapogon avrnuceus, e. alba, e. crus-galli and c. dactylon; while abundant weeds were s. halepense, p. hysterophorus, c. rotundus, c. arvense, carduus argentatus, and a. viridis. wheat, rice and maize fields were dominated by c. dactylon, c. rotundus, asphodelus tenuifolius, astragalus hamosus, c. arvensis, and e. helioscopia.