A field experiment was conducted at University of Agricultural Sciences, Dharwad during Kharif Season under rainfed condition to now the influence of weed composts.  Parthenium hysterophorus, Cassia serecia, and Chromolaena odorata  weed composts were prepared at preflowering and postflowering stage while Portulaca oleracea at preflowering stage.  These composts were compared with farm yard manure (FYM), vermin compost and poultry manure in combination with recommended dose of fertilizer (RDF).  Before application to the filed these composts were analyzed for major nutrients composition.  The highest N content ( 2.95%) was noticed  in Parthenium compost (before flowering)  followed by Chromolaena (2.32 %.  While P content was more in poultry manure ( 1.60%) Potatssium content was higher in poultry manure (1.42%)  and Parthenium compost (1.39%). Among the treatments., application of poultry manure + RDF recorded highest LAI (4.81), photosynthetic rate (36.1 µ mol co2 m-2 s-1) and grain yield ( 35.5 q ha-1) with better partitioning efficiency ( 41%).  The next best treatment was RDF in combination with Parthenium compost (prepared at preflowering stage) which had on par yield of 30.7 q ha-1 with poultry manure.  Composts prepared from weed species before flowering stage had more beneficial effects than the composts prepared at later stages because of higher nutrients content.  Whereas, the compost prepared at postflowering stage contained more viable weed seeds.