Effect of different weed control measures on physiological growth parameters of cumin (Cuminum cyminum L.) at different dates of sowing under arid western Rajasthan

A field experiment titled “Effect of different weed control measures on physiological growth parameters of cumin (Cuminum cyminum L.) at different dates of sowing under arid western Rajasthan” was conducted at the College of Agriculture, Bikaner, during the rabi seasons of 2021-2022 and 2022-2023. The study employed a split plot design with four sowing dates (01 November, 15 November, 30 November, and 15 December) as main plots and seven weed control treatments as subplots: Weedy check (control), weed-free, Pendimethalin (1.0 kg ha^-1, pre-emergence), Pendimethalin + Oxyfluorfen (500 g ha^-1, pre-emergence), Flumioxazin (100 g ha^-1, pre-emergence), Oxyfluorfen (50 g ha^-1, post-emergence), and Oxadiargyl (50 g ha^-1, post-emergence). The experiment was replicated three times. The findings underscore the importance of timely sowing for maximizing growth rates in cumin. Early sowing not only enhances crop growth during the initial stages but also contributes to overall yield potential by improving plant establishment. As sowing was delayed to November 15 and November 30, a gradual decline in growth rate was noted, with pooled values of 0.108 g m²; day^-1; and 0.102 g m²; day^-1;, respectively. The lowest growth rate was observed for the December 15 sowing, with a pooled average of only 0.073 g m²; day^-1;.The relative growth rate (RGR) varied significantly across different sowing dates. Notably, the RGR increased with delayed sowing from November 1 to December 15, with the highest pooled RGR of 43.72 mg g^-1; day^-1; recorded for the December 15 sowing date. The weed-free treatment consistently yielded the highest growth rates, with pooled averages of 0.124 g m²; day^-1; for the initial 45 days. Among the chemical weed control treatments, Pendimethalin + Oxyfluorfen (500 g ha^-1;) and Oxyfluorfen (50 g ha^-1;) performed relatively well, with pooled growth rates of 0.094 g m²; day^-1; and 0.108 g m²; day^-1;, respectively.