Pecan (Carya illinoensis Koch.) is one of the most important nut fruits of the world. As in many cropping systems weeds are present problems in pecan orchards and compete with trees for water, light, and nutrients. However, the effects of this competition vary throughout the life of the tree. In newly planted pecan orchards, weed competition can decrease survival and severely retard tree growth, production and productivity. The treatment of our work includes black polythene mulch (200 gauge), hay mulch (10-15cm thickness), atrazine (4 kg/ha), glyphosate (0.8 kg/ha), black polythene mulch +atrazine (3 kg/ha), black polythene mulch+ glyphosate (0.8 kg/ha), hay mulch +atrazine (3 kg/ha), hay mulch +glyphosate (0.8 kg/ha), atrazine (3 kg/ha) + glyphosate (0.8 kg/ha), hand weeding at monthly interval and unweeded control. The present work demonstrated that the treatment combination of Hay mulch + atrazine @ 3kg/ ha resulted in the highest tree height (m), growth, trunk girth (mm), tree volume (m3), nut weight (g), kernel length (mm), kernel breadth (mm), kernel weight (g), kernel (%) and kernel oil (%) in comparison to unweeded control. It was found that treatment hay mulch gave maximum flowering, fruit set (%), fruit retention (%) and yield (kg/tree). Black polythene mulch gave the highest soil temperature and flowering percentage. Weed control efficiency was maximum under treatment combination of black polythene + glyphosate @ 0.8 kg/ha