RESPONSE OF MAIZE AND THREE PERENNIAL WEEDS TO DIFFERENT COMBINATIONS OF MACRO-NUTRIENTS

Pot experiment was conducted in the department of weed science, the university of agriculture, peshawar, pakistan in july 2009 investigating the response of three perennial weeds and maize to different combinations of macro-nutrients. the experiment was laid out in completely randomized design and each treatment being replicated three times. there were eight treatments comprising the control (no macro-nutrients), nitrogen (n), phosphorous (p), potassium (k) and the combinations of np, nk, pk and npk. the doses of npk each alone and in mixture were 300, 200 and 100 mg kg-1 soil. five seeds of maize and three rhizomes/stolons of cyperus rotundus, cynodon dactylon and sorghum halepense were planted in pots. analysis of the data revealed that all the fertilizers significantly increased the growth parameters of the weed species and the crop studied. however combine use of the macro-nutrients were more effective in promoting the plant height, fresh plant biomass, dry plant biomass and the plants root weight as compared using them alone. the present findings revealed that macro-nutrients (fertilizer) application in maize not only favour the crop growth but also promote the growth of the three perennial test weeds. thus band application of the macro-nutrients may show advantages over the broadcast application as npk is shared equally by weeds and maize as well.