Nutrient utilization by cumin (Cuminum cyminum) and weeds as influenced by different weed-control methods

A field study was conducted during the winter season of 2003–04 and 2004–05 at Mandor, Jodhpur with 15 weed-management treatments, to study the nutrient uptake by cumin (Cuminum cyminum L.) and depletion by associated weeds. Amongst the weed-management treatments, oxyfluorfen and oxadiargyl at 50 g/ha applied 20 days after sowing (DAS) along with 1 hand-weeding 35 DAS caused maximum reduction in weed biomass production and nutrient depletion by weeds 90 DAS and resulted in higher weed-control efficiency. These treatments also enhanced cumin yield, essential oil content in the seed and uptake of N, P and K by the crop and net monetary returns. Weeds in check plots cornered 93.5 kg N, 14.5 kg P and 142.6 kg K/ha recorded 90 DAS, which was significantly higher than in other treatments. Paraquat and glyphosate applied 7 DAS failed to check depletion of nutrients by weeds significantly. Application of oxadiargyl @ 50 g/ha applied 20 DAS was found better than its application 7 DAS. Early post-emergence application of oxyfluorfen and oxadiargyl 50 g/ha followed by 1 hand-weeding computed considerably higher net returns (Rs 25,595 and 24,823/ha respectively) and benefit: cost ratio (2.92 and 2.80), and lower nutrient uptake compared to other integrated weed-control treatments.