AGRO-ECONOMIC IMPACT OF ORGANIC MULCHES ON WEED DYNAMICS AND PRODUCTIVITY OF RAINFED WHEAT (Triticum aestivum L.)

Wheat is a widely grown cereal crop under rainfed conditions of semi-arid areas of the world including Pakistan. Unfortunately, its yield remains low due to heavy weed infestation and scarce moisture supply in the root zone from erratic rainfall. Therefore, a field experiment was conducted to observe the influence of different organic mulches on the soil moisture, weeds, growth and yield of wheat crop. Four organic mulches i.e wheat straw sawdust, rice straw and rice husk were applied up to 2 inches surface layer between the rows of wheat crop.  Application of wheat straw mulch conserved the highest soil moisture (72.3%) at 0-15cm depth six weeks after sowing and caused maximum weed suppression with 81.17% weed control efficiency and 63.70% weed control index as compared to unmulched control. Maximum plant height (70.8cm), productive tillers (137.33 m-2), grain weight per spike (2.37g), grains per spike (52.3), 1000-grain weight (50.66 g), biological yield (9393.9 kg ha-1), grain yield (3665.6 kg ha-1), harvest index (38.60%) and benefit-cost ratio (1.69) were observed in rainfed wheat crop treated with wheat straw mulch. Wheat crop total rainfall use efficiency followed the order of wheat straw > rice straw > saw dust> rice husk> control. The highest weed density and dry weight while lowest soil moisture and grain yield were recorded with no mulch and rice husk treatments.