in this research corn were planted in 3 densities (8, 12, 16 plant/m2) in two planting patterns (single and double-row) with seven summer weed species, including redroot pigweed, green foxtail, annual bluegrass, common lambsquarter, jimsonweed, black nightshade and johnsongrass were planted. temperature, quality and quantity of light reaching to soil surface were measured and the number of emer...