TURKISH JOURNAL OF AGRICULTURE AND FORESTRY-Turk J Agric For E-ISSN: 1303-6173 ISSN: 1300-011X Year: 2021 Volume: 45 Number: 1 Assessment of growth, flowering and seed yield in Calendula ( Calendula officinalis L.) as influenced by gold-nanoparticle Ranjan K. Srivastava 1 *, Satish Chand, B.D. Bhuj, Ajit Kumar, Rajat Sharma and Sheeba Belwal Department of Horticulture, G.B. Pant University of Agriculture & Technology, Pantnagar-263 145, INDIA Abstract Gold-nanoparticles spray influences growth, flowering and seed yield of Calendula. Experiment consisted of four treatments (5, 10, 15, 20 ppm Gold-nanoparticle), along with control and was laid out in Randomized Block Design with four replications. Foliar application of Gold- nanoparticle suspension was done 25 days after transplanting of seedlings to the experimental field. Among the various treatments, application of 10 ppm of Gold-nanoparticle was found best for most of the parameters viz., plant height (73.95 cm), plant spread (54.62), number of leaves (127.55), flower diameter(7.06 cm), fresh flower weight (4.31 g), days to flower bud initiation (30.85 days), duration to flowering (105.15 days), total number of flowers (131.30), seed weight (35.73 g), estimated flower yield (28 tons/ha). Key words: Calendula, Gold-nano particles, growth, flowering, seed yield Introduction: Calendula (Calendula officinalis) commonly known as pot marigold or poor man’s saffron is linked to the astrological sign of summer as the flowers follow the sun. Commercially, calendula is extensively grown in beds, baskets and boxes. Flowers are sold in the market as loose or for making garlands. Flowers are also gaining popularity as cut flower, and traditionally used for offering in churches and temples for use in ceremonies, festivals, beautification and landscape plans. Calendula plant was grown by Egyptians, Arabs, Indians, and Greeks for medicinal purposes during 12th century (Zaman, 24).In Europe, calendula flowers have been introduced as drug in 1 Email: ranjansrivastava25@gmail.com