Effect of sowing time, varieties and plant growth regulators on growth, physiological indices and productivity of coriander (Coriandrum sativum)

A field experiment was conducted during winter (rabi) seasons of 2011-12 and 2012-13 at Agronomy Farm, Jobner, Rajasthan, to study the response of coriander (Coriandrum sativum L.) varieties to plant-growth regulators under normal and late-sown conditions grown on irrigated loamy sand soil of semi-arid Eastern Plains Zone of Rajasthan. The experiment consisting of 2 sowing times (normal in the first week of November and late sown in the third week of November), 3 varieties ('RCr 41', 'RCr 435' and 'ROI* 480') and 5 plant-growth regulators (PGR), i.e. control (water sprayed), triacontanol @ 1,000 ppm, brassinolide @ 1 ppm, thiourea @ 1,000 ppm and naphthalene acetic acid (NAA) @ 50 ppm at 40 and 70 days after sowing (DAS) making 30 treatment combinations, were replicated thrice in split a plot design, keeping dates of sowing and varieties in main-plots and PGR treatments in subplots. The crop sown at normal sowing time showed significantly higher values of the growth parameters and physiological indices and seed yield (1.48 t/ha), stover yield (2.20 t/ha) and net returns (sic 32,810/ha) than the late-sown crop. Variety 'RCr 435', being at par with 'RCr 480', showed significantly higher growth and better physiological indices at all the growth stages. However, the highest seed (1.37 t/ha) and stover (2.03 t/ha) yields and net returns (sic 28,478/ha) were obtained from 'IRCr 480' coriander. Foliar spray of 1,000 ppm thiourea significantly increased the crop growth at all the stages/phases over other PGRs and remained at par with triacontanol. However, foliar spray of 1,000 ppm triacontanol significantly increased the seed (1.40 t/ha) and stover (2.12 t/ha) yields and net returns (sic 30,020/ha) as compared to the other PGRs, while it was at par with brassinolide.