Effect of Graded Levels of Nutrients and Organic Amendments on Growth and Flower Yield of African marigold (Tagetes erecta L.)
Authors: Murugan V. Thirumal , Manivannan K. , Nanthakumar S. 
Published: March 2022

Production of marigold can be improved to a large extent by the judicious cultural operations i.e., application of optimum fertilizer at required time and appropriate crop management practices. Excessive application of chemical fertilizers produces adverse effects on the atmosphere and groundwater quality, causing several health hazards. In India, effective nutrient management has played a major role in accomplishing the enormous increase in food production. However, it is not possible to supply all the nutrient requirements of crops through inorganic fertilizers. Integrated Nutrient Management provides an excellent opportunity to sustain soil health and enhance the crop production. To improve the physical, chemical and biological properties of the soil, and increase the efficiency of applied fertilizers, apply the required quantity of organic manures and bio-fertilizers along with balanced use of chemical fertilizers [1].

In this experiment, the organic amendments viz., Vermicompost, Humic acid and Arka microbial consortium applied as basal and the recommended full dose of phosphorus through single super phosphate and pottasium through Muriate of potash were applied just before transplanting of seedlings. Nitrogen through urea was applied in two split doses, i.e., first ½ dose of total nitrogen was applied at the time of transplanting of seedlings and remaining dose of nitrogen was applied at 45 DAT according to the treatment combinations. The experiment was carried out in Randomized Block Design with three replications and thirteen treatment combinations viz. Control (RDF 100% - 90:90:75 kg N, P2O5 and K2O kg ha-1) (T1), RDF 75% + Vermicompost (T2), RDF 100% + Vermicompost (T3), RDF 75% + Humic acid (T4), RDF 100% + Humic acid (T5), RDF 75% + Vermicompost + Humic acid (T6), RDF 100% + Vermicompost + Humic acid (T7), RDF 75% + Humic Acid + Arka microbial consortium (T8), RDF 100% + Humic Acid + Arka microbial consortium (T9), RDF 75% + Vermicompost + Arka microbial consortium (T10), RDF 100% + Vermicompost + Arka microbial consortium (T11), RDF 75% + Vermicompost + Humic Acid + Arka microbial consortium (T12), RDF 100% + Vermicompost + Humic Acid + Arka microbial consortium                   (T13).

The treatment T13 recorded the maximum plant height (109.28 cm), number of branches plant-1 (18.74) and number of leaves plant-1 (136.94) were recorded for those plants applied with RDF 100% + Vermicompost + Humic Acid + AMC (T13) in 30, 60 and 90 days after transplanting. Similarly, maximum single flower weight (6.95 g), number of flowers plant-1 (58.42), flower yield plant-1 (312.63 g) and plot-1 (10.5 kg), estimated flower yield 13.86 t ha-1 and xanthophyll content (18.26 g kg-1 of petal meal). Hence, it is concluded that application of Vermicompost @ 5 t ha-1 + Humic acid @ 5 kg ha-1 along with Arka microbial consortium@ 12.5 kg ha-1 in addition with 100 % RDF (90:90:75 kg N, P2O5 and K2O kg ha-1) will be effective in increasing the growth, flower yield and xanthophyll content of African marigold.