The occurrence of weeds and the shape of the planting are two of the most important factors affecting fennel performance in limited irrigation conditions of semi–arid ecologies. Adoption of weed management practices under different plant rectangularity may lead towards achieving higher productivity with system sustainability. A two–year field experiment was conducted at semi–arid climatic conditions of Rajasthan in the rabi season of 2016–2018 to investigate the response of fennel crop to weed management practices under different planting geometry. The twenty four treatment combinations, comprising four plant rectangularity viz. 50 x 20 cm, 50 x 25 cm, 60 x 15 cm and 60 x 20 cm with six weed management practices viz. weedy check, two HW at 25 and 50 DAS, pendimethalin @ 0.75 kg/ha (PE), oxadiargyl @ 75 g/ha (PE), pendimethalin @ 0.75 kg/ha (PE) + one HW at 30 DAS and oxadiargyl @ 75 g/ha (PE) + one HW at 30 DAS. These treatments were replicated thrice in split spot design and analyzed. Result illustrated that significantly (p <0.05) highest seed yield (22.13 q/ha), straw yield (74.46 q/ha) and biological yield (96.59 q/ha) were recorded in plant rectangularity60 x 20 cm over plant rectangularity’s 50 x 25 cm, 50 x 20 cm and 60 x 15 cm. Similarly, respective nutrient content and their uptake in plant samples were increase under plant rectangularity 60 x 20 cm. Among the weed management practices, HW twice at 25 and 50 DAS significantly (p <0.05) improved the yield, nutrient content and their uptake by fennel followed by pendimethalin @ 0.75 kg/ha (PE) + one HW at 30 DAS, oxadiargyl @ 75 g/ha (PE) + one HW at 30 DAS and pendimethalin @ 0.75 kg/ha (PE) and proved superior over pre-emergence application of oxadiargyl @ 75 g/ha and weedy check.